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UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

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Commission File Number: 001-33480

CLEAN ENERGY FUELS CORP.

(Exact name of registrant as specified in its charter)

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4675 MacArthur Court, Suite 800, Newport Beach, CA 92660
(Address of principal executive offices, including zip code)

(949) 437-1000
(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

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Securities registered pursuant to section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes  ☒     No  ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes  ☐     No  ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes  ☒     No  ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes  ☒     No  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

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If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes  ☐     No  ☒

The aggregate market value of the voting stock held by non-affiliates of the registrant as of June 30, 2023, the last business day of the registrant’s most recently completed second fiscal quarter, was approximately $879,338,902. The treatment of persons as affiliates of the registrant for purposes of this calculation is not, and shall not be considered, a determination as to whether any such person is an affiliate of the registrant for any other purpose.

As of February 22, 2024, there were 223,238,496 shares of the registrant’s common stock, par value $0.0001 per share, issued and outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive proxy statement for its 2024 annual meeting of stockholders are incorporated by reference in Part III of this report.

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Clean Energy Fuels Corp.

Annual Report on Form 10-K

For the Fiscal Year Ended December 31, 2023

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This annual report on Form 10-K contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Forward-looking statements are statements other than historical facts. These statements relate to future events or circumstances or our future performance, and they are based on our current assumptions, expectations and beliefs concerning future developments and their potential effect on our business. In some cases, you can identify forward-looking statements by the following words: “if,” “may,” “might,” “shall,” “will,” “can,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “goal,” “objective,” “initiative,” “anticipate,” “believe,” “estimate,” “predict,” “project,” “forecast,” “potential,” “continue,” “ongoing” or the negative of these terms or other comparable terminology. The absence of these words, however, does not mean that a statement is not forward-looking. The forward-looking statements we make in this report include statements about, among other things, our future financial and operating performance, our growth strategies, including expectations regarding our delivery and sales of RNG (as defined below) and sale of U.S. federal, state and local government credits, and anticipated trends in our industry and our business.

The preceding list is not intended to be an exhaustive list of all of the topics addressed by our forward-looking statements. Although the forward-looking statements we make reflect our good faith judgment based on available information, they are only predictions of future events and conditions. Accordingly, our forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our or our industry’s actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by our forward-looking statements. Factors that might cause or contribute to such differences include, among others, those discussed in Item 1A. Risk Factors of this report, as such factors may be amended, supplemented or superseded from time to time by other reports we file with the Securities and Exchange Commission (the “SEC”). In addition, we operate in a competitive and rapidly evolving industry in which new risks emerge from time to time, and it is not possible for us to predict all of the risks we may face. Nor can we assess the impact of all factors on our business or the extent to which any factor or combination of factors could cause actual results to differ from our expectations. As a result of these and other potential risks and uncertainties, our forward-looking statements should not be relied on or viewed as guarantees of future events or conditions.

All of our forward-looking statements in this report are made only as of the date of this document and, except as required by law, we undertake no obligation to update publicly any forward-looking statements for any reason, including to conform these statements to actual results or to changes in our expectations. You should, however, review the factors and risks we describe in the reports we will file from time to time with the SEC for the most recent information about our forward-looking statements and the risks and uncertainties related to these statements.

We qualify all of our forward-looking statements by this cautionary note.

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Unless the context indicates otherwise, all references to “Clean Energy,” the “Company,” “we,” “us,” or “our” in this report refer to Clean Energy Fuels Corp., together with its majority and wholly owned subsidiaries.

We own registered or unregistered trademark or service mark rights to Clean Energy™ and Clean Energy Renewables™. Although we do not use the “®” or “™” symbol in each instance in which one of our trademarks appears in this report, this should not be construed as any indication that we will not assert our rights thereto to the fullest extent under applicable law. Any other service marks, trademarks and trade names appearing in this report are the property of their respective owners.

Investors and others should note that we disseminate information to the public about our Company, our products, services and other matters through various channels, including our website (www.cleanenergyfuels.com), SEC filings, press releases, public conference calls and webcasts, in order to achieve broad, non-exclusionary distribution of information to the public. We encourage investors and others to review the information we make public through these channels, as such information could be deemed to be material information.

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PART I

Item 1.   Business.

Overview

Clean Energy Fuels Corp., a Delaware corporation, is a leading renewable energy company focused on the procurement and distribution of renewable natural gas (“RNG”) and conventional natural gas, in the form of compressed natural gas (“CNG”) and liquefied natural gas (“LNG”), for the United States (“U.S.”) and Canadian transportation markets. RNG, which is delivered as either CNG or LNG, is created by the recovery and processing of naturally occurring, environmentally detrimental waste methane (“biogas”) from non-fossil fuel sources – such as dairy and other livestock waste and landfills – for beneficial use as a replacement for fossil-based transportation fuels. Methane is one of the most potent climate-harming greenhouse gases (“GHG”) with a comparative impact on global warming that is about 28 times more powerful than that of carbon dioxide. We are focused on developing, owning, and operating dairy and other livestock waste RNG projects and supplying RNG (currently procured from third party sources and from our anaerobic digester gas (“ADG”) RNG joint venture project with TotalEnergies S.E. (the “DR JV”) (see Note 4)) to our customers in the heavy and medium-duty commercial transportation sectors. We have participated in the alternative vehicle fuels industry for over 20 years. We believe we are in a unique position because the valuable Environmental Credits (as defined below) are generated by the party that dispenses RNG into vehicle fuel tanks, and we believe we have access to more dispensers than any other market participant.

We believe we were the first organization to supply RNG for vehicle fuel use in the U.S., and sales of our RNG for such purpose have increased from 13.0 million gasoline gallon equivalents (“GGEs”) in 2013 to 225.7 million GGEs in 2023. We calculate one GGE to equal 125,000 British Thermal Units (“BTUs”) and, as such, one million BTUs (“MMBTU”) equals eight GGEs. We are North America’s leading provider of the cleanest fuel for the commercial transportation market, based on both the number of stations we operate and the amount of GGEs serviced and GGEs sold of RNG and conventional natural gas, in the form of CNG and LNG, which amounted to a total of 466.2 million GGEs in 2023. With the Company’s focus on RNG, our sales of RNG have grown from 12% of our vehicle fuel sales in 2013 to 89% of our vehicle fuel sales in 2023 (excluding GGEs from O&M (as defined below) services sales and non-vehicle sales). We believe that during 2023 we provided 53% and 47% of the RNG used for transportation fuel in California and the U.S., respectively.

As a comprehensive clean energy solutions provider, we also design and build, as well as operate and maintain (“O&M”), public and private vehicle fueling stations in the U.S. and Canada; sell and service compressors and other equipment used in RNG production and at fueling stations; transport and sell RNG and conventional natural gas via “virtual” natural gas pipelines and interconnects; sell U.S. federal, state and local government credits (collectively, “Environmental Credits”) we generate by selling RNG as a vehicle fuel, including Renewable Identification Numbers (“RIN Credits” or “RINs”) under the federal Renewable Fuel Standard Phase 2 and credits under the California, Oregon, and Washington Low Carbon Fuel Standards (collectively, “LCFS Credits”); and obtain federal, state and local tax credits, grants and incentives. We serve fleet vehicle operators in a variety of markets, including heavy-duty trucking, airports, refuse, public transit, industrial and institutional energy users, and government fleets. We believe these fleet markets will continue to present a growth opportunity for our vehicle fuels for the foreseeable future.

Commercial transportation, including heavy-duty trucking, generates a significant portion of the emissions of overall carbon dioxide and other climate-harming GHGs, and transitioning this sector to low and negative carbon fuels is a critical step towards reducing overall global GHG emissions. According to the Global Carbon Project’s Global Carbon Budget published in December 2023 and International Energy Agency’s topic analysis on transport, 37.1 billion metric tons of carbon dioxide were emitted globally in 2022, of which 8.0 billion metric tons, or 22%, came from the transportation sector. There is a global demand for reducing GHG emissions, as evidenced by 96% of the world’s countries having committed to the Paris Agreement according to The United Nations Framework Convention in Climate Change, and 98% of S&P 500 companies focusing on sustainability metrics, including GHG emissions, according to the Governance & Accountability Institute’s Flash Report published in 2023.

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Biogas, the primary source of RNG, is produced by microbes as they break down organic matter in the absence of oxygen. Our sources of commercial scale biogas are ADG, which is produced inside an airtight tank used to breakdown organic matter such as dairy and other livestock waste, and landfill gas (“LFG”), which is produced by the decomposition of organic waste at landfills.

Given the potential growth and positive environmental impact of RNG, our mission is to obtain as much RNG supply as possible. To that end we are pursuing development and ownership of dairy and other livestock waste ADG projects on our own and with partners including TotalEnergies S.E. (“TotalEnergies”) and BP Products North America (“bp”). Further, we enter long-term RNG supply offtake agreements with well-known third parties that own RNG production facilities. Because our business transforms waste methane into a renewable source of energy, our RNG generates valuable Environmental Credits under federal and state initiatives.

Depending on the source, the California Air Resources Board (“CARB”) has determined that RNG can have a significantly negative carbon intensity score, enabling our customers to achieve a net carbon negative emissions profile.

California Air Resources Board “Current Fuel Pathways” Q2 2021 to Q3 2023
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At present, we see the best use of RNG as a replacement for fossil-based fuel in the transportation sector. We believe the most attractive market for RNG is U.S. heavy-duty Class 8 trucking and, based on information from the American Trucking Association and our own internal estimates, we believe there are approximately 4.1 million Class 8 heavy-duty trucks operating in the U.S. that use over 40 billion gallons of fuel per year. As of December 31, 2023, we deliver RNG to the transportation market through 579 fueling stations we own, operate or supply in 43 states and the District of Columbia in the U.S., including over 200 stations in California. We also own, operate, or supply 24 fueling stations in Canada as of December 31, 2023. Critically, to generate valuable Environmental Credits, the RNG must be placed in vehicle fuel tanks. We believe our stations and customer relationships allow us to sell substantially more RNG to vehicle operators than any other participant in the market – we calculate that we have access to more fueling stations and vehicle fleets than all our competitors combined. As of December 31, 2023, we served over 1,000 fleet customers operating over 50,000 vehicles on our fuels. We believe we are the only company in the U.S. that provides RNG vehicle fuel at scale in California and nationally.

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Longer term, we plan to expand availability of hydrogen fuel for vehicle fleets. As operators deploy more hydrogen powered vehicles, we can modify our fueling stations to reform our RNG and deliver clean hydrogen to customers. We also believe our RNG can be used to generate clean electricity to power electric vehicles, and we have the capability to add electric vehicle charging at our station sites, although the cost of adding electric vehicle charging capacity may be significant.

Our Principal Products, Services and Other Business Activities

Our principal products, services and other business activities are described below. Information about the revenue we receive from these activities is discussed in this report in Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Fuel Sales

We sell RNG and conventional natural gas, in the form of CNG and LNG, as fuel for medium and heavy-duty vehicles.

Conventional natural gas is typically sourced from local utilities or third-party conventional natural gas marketers. We purchase conventional natural gas under North American Energy Standards Board base contracts on a spot market or short-term forward index basis or forward purchase contracts under take-or-pay arrangements that require us to purchase minimum volumes of conventional natural gas. Conventional natural gas is purchased on a normal purchase normal sale basis, as the conventional natural gas we purchase is for physical delivery of the commodity to our fueling stations for sale to customers.

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Sales of Environmental Credits.   We generate Environmental Credits consisting of RINs and LCFS Credits when we sell RNG for use as a vehicle fuel in the U.S. We sell these Environmental Credits to third parties who must comply with federal and state emissions requirements. Generally, the number of Environmental Credits we generate increases as we sell higher volumes of RNG as a vehicle fuel. The number of Environmental Credits we sell and our revenue from these sales can vary depending on a number of factors, including the market for these credits, which has been volatile and subject to significant price fluctuations in recent periods (for example, in 2023, market prices for RINs were as high as $3.55 and as low as $1.88), any changes to the federal and state programs under which the credits are generated and sold, and our ability to strictly comply with these programs.

O&M Services.   We perform maintenance service on Clean Energy-owned and customer-owned fueling stations. Our maintenance program is backed by over 200 company employed service technicians and support personnel, an in-house 24/7 remote monitoring center, technician training center, computerized maintenance management system and inventory warehouses throughout the U.S. and Canada. For maintenance services, we generally charge a fixed fee or per gallon fee based on volume of fuel dispensed at the station.

Station Construction and Engineering.    We design and construct fueling stations and sell or lease some of these stations to our customers. Since 2008, we have served as the general contractor or supervised qualified third-party contractors to build over 460 natural gas fueling stations.

Grant Programs.    We apply for and help our fleet customers apply for federal, state and local grant programs in areas in which we operate. These programs can provide funding for vehicle purchases, fueling station construction and vehicle fuel sales.

Our Company’s Sustainability Program

Our vision is to deliver renewable transportation fuel for a cleaner, safer, more equitable tomorrow. We have a bold program, supported by ambitious goals to drive progress across four key pillars: fueling the transition to renewable energy in transportation, building the workforce for the future of renewable energy, advancing smart policies that drive the transformation to zero carbon fuels, and earning stakeholder trust.

Fueling transportation’s transition to renewable energy.

The fuel we provide enables our customers to transition from diesel to a solution with significantly lower GHG emissions and air quality impacts today. We are committed to pushing ourselves and our partners further by helping to produce and distribute 100% RNG, which can have a low carbon profile. We are also committed to doing our part to reduce our own emissions across our operations and supply chain.

Building the workforce for the future of renewable energy.

At Clean Energy we have always had a strong focus on employee and contractor safety and strive to be a zero-incident workplace for our service technicians and staff, as well as our customers using our facilities. Looking towards the future, we will continue to focus on employee recruitment, retention, and engagement. It is important that we build a leadership

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team and supplier base that are reflective of the communities in which we operate. We acknowledge the lack of diversity in the energy sector and strive to be part of the solution.

Advancing smart policies that drive the transformation to zero carbon fuels.

Widespread change will be necessary across all industries to achieve our collective climate goals. We recognize that some physical climate impacts are unavoidable in the near-term and that the transition to a low carbon economy may bring new risks to our business. We also recognize that natural gas extraction and processing causes environmental and social impacts that must be appropriately managed. By investing in the energy transition, our aim is to reduce our own risks and provide lasting benefits to society. To enable lasting change, we must ensure the adoption of performance-driven state and federal policies that accelerate the shift from diesel and other transportation fuels with high GHG emissions and negative air quality impacts to zero net carbon emission transportation fuels. We are also committed to contributing to quality of life improvement and economic development in the communities where we conduct business, many of which are disadvantaged communities that suffer from poor air quality due to the use of transportation fuels, including diesel, that have high GHG emissions and significantly negative air quality impacts.

Earn stakeholder trust.

To realize our ambitious goals we are building trusted partnerships with our stakeholders. We strive to act ethically and responsibly in all aspects of our business, seeking to meet expectations related to human rights, labor standards, air quality, water stewardship, operational energy efficiency, biodiversity and land use, disaster preparedness, business ethics, and other material topics.

Market Opportunity

Increasing demand for RNG

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Demand for RNG produced from biogas is significant and growing in large part due to an increased focus by the U.S. public and investors, as well as federal, state, and local regulatory authorities, on reducing the emission of GHG, such as methane. According to the U.S. Environmental Protection Agency (“EPA”), methane is a significant GHG, which accounted for roughly 12% of all U.S. GHG emissions from human activities in 2021 and which has a comparative impact on global warming that is about 28 times more powerful than that of carbon dioxide over a 100-year period. Biogas processing facilities substantially reduce methane emissions at livestock farms and landfills, which together accounted for approximately 40% of U.S. methane emissions in 2021 according to the EPA.

Over the past decade we have seen the transportation sector be the fastest growing end market for RNG, where RNG is used as a replacement for fossil-based fuel. This growth has been principally driven by an increased focus on reducing GHGs, as well as Environmental Credits to support the production of renewable transportation fuels. According to NGV America, a national organization dedicated to the development of a growing, profitable, and sustainable market for vehicles powered by RNG, in 2022, “RNG use as a transportation fuel increased 218% from 2018 levels, and RNG use as a motor fuel displaced 5.63 million metric tons of carbon dioxide equivalent.” Further, RNG engines now commercially available for heavy-duty, regional-haul, refuse, transit, and vocational applications have been certified to satisfy CARB’s optional low nitrogen oxide (“NOx”) emission standard of 0.02 g/bhp-hr. This means that these engines emit 90% less smog-forming NOx than the existing regulatory standards, making them the lowest certified ultra-low NOx emission engines in the U.S.

Given public and investor calls for, and U.S. federal, state, and local regulatory trends and policies aimed at, reducing GHG emissions, we expect continued regulatory support for RNG as a replacement for fossil-based fuels and therefore continued and growing demand for RNG in the foreseeable future.

Increasing vehicle availability

RNG is a replacement for fossil-based fuel consumed by vehicles that use internal combustion engines like those used in gasoline- or diesel-powered vehicles. Virtually any car, truck, bus, or other vehicle is capable of being manufactured to

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run on RNG. Many types and models of heavy- and medium-duty RNG vehicles and engines are available in the U.S., including, among others, long-haul tractors, refuse trucks, regional tractors, transit buses, ready-mix trucks, delivery trucks, vocational work trucks, school buses, shuttles, pickup trucks and cargo and passenger vans.

More broadly, many companies are developing and commercializing hydrogen and electric commercial vehicles, particularly as the commercial transportation sector increasingly shifts toward low-emission, zero-emission, or carbon neutral vehicle solutions. Various manufacturers have announced their plans to bring long-haul Class 8 commercial hydrogen- and battery-powered vehicles to the market over the coming years.

Availability of long-term feedstock supply

Biogas is collected and processed to remove impurities for use as RNG and injected into existing natural gas pipelines. RNG is fully interchangeable with and chemically identical to conventional natural gas. Common sources of biogas include livestock farms, landfills, and wastewater resource recovery facilities.

Livestock- and landfill-sourced biogas represent a significant opportunity to produce RNG and reduce GHG emissions. Although LFG has accounted for most of the growth in biogas projects to date, biogas from dairy and other livestock farm waste represents significant opportunities for RNG production that remain largely untapped. According to ICF Consulting, Inc., the global consulting services company, by 2040, the U.S. has the technical potential to annually produce up to 34.4 billion GGEs of RNG, including up to 20.6 billion GGEs of ADG RNG.

All-in prices paid for RNG from livestock farms can be significantly higher than prices for RNG from landfills due to higher value available from state-level low-carbon fuel incentives for these projects. Given our market leadership in RNG, we believe we are well-positioned to take advantage of this market.

TotalEnergies Joint Venture

On March 3, 2021, we entered into an agreement (the “TotalEnergies JV Agreement”) with TotalEnergies to create 50/50 joint ventures to develop ADG RNG production facilities in the U.S. The TotalEnergies JV Agreement contemplates investing up to $400.0 million of equity in production projects, and TotalEnergies and the Company each committed to initially provide $50.0 million. Pursuant to the TotalEnergies JV Agreement, the Company and TotalEnergies have given each party a limited right of first opportunity to invest in ADG RNG projects they respectively originate. Currently, there is one ADG RNG joint venture project (the DR JV) in operation pursuant to the TotalEnergies JV Agreement. This project is estimated to produce up to 1.1 million GGEs of RNG annually, all of which will be available to the Company for sale to the vehicle fuels market.

bp Joint Venture

On April 13, 2021, pursuant to a memorandum of understanding we entered into with bp in December 2020, we entered into an agreement (“bp JV Agreement”) with bp that created a 50/50 joint venture (the “bpJV”) to develop, own and operate new ADG RNG production facilities in the U.S. From inception to December 31, 2023, we and bp have collectively contributed approximately $455.5 million of equity to the bpJV. Currently, there are five ADG RNG projects under construction, which are planned to be substantially complete between the first quarter of 2024 and the first quarter of 2025, and one ADG RNG project, located at Drumgoon Dairy, in operation. The RNG project at Drumgoon Dairy is designed to produce approximately 1.7 million GGEs of RNG annually when at full capacity. Collectively, the six ADG RNG projects in the bpJV are currently estimated to produce up to 11.1 million GGEs of RNG annually, and 100% of the RNG produced from these projects will be available to us for sale as vehicle fuel pursuant to our existing marketing agreement with bp.

The Company’s RNG projects

As of December 31, 2023, we had three 100% owned ADG RNG projects under development, which are anticipated to be substantially complete between the second and third quarter of 2025. In accordance with the TotalEnergies JV Agreement, we will provide TotalEnergies with the right of first opportunity to invest in these ADG RNG projects

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alongside the Company. Collectively, our three 100% owned ADG RNG projects will have an estimated RNG production volume of 3.6 million GGEs per year, all of which will be available to us for sale to the vehicle fuels market.

Tourmaline Joint Development

On April 18, 2023, we and Tourmaline Oil Corp. (“Tourmaline”) announced a CAD $70 million Joint Development Agreement to build and operate a network of CNG stations along key highway corridors across Western Canada. Under a 50-50 shared investment, we and Tourmaline expect to construct and commission up to 20 CNG fueling stations over the next five years, allowing heavy-duty trucks and other commercial transportation fleets that operate in the area to transition to the use of CNG, a lower carbon alternative to gasoline and diesel.

Use of environmental credits to promote RNG growth

When used as a transportation fuel, RNG generates additional revenue streams through Environmental Credits. These Environmental Credits are provided under a variety of programs, including the national Renewable Fuel Standards (“RFS”), and state-level Low Carbon Fuel Standard (“LCFS”) programs.

The RFS program requires transportation fuel to contain a minimum volume of renewable fuel. To fulfill this regulatory mandate, the EPA obligates refiners and importers (“Obligated Parties”) to blend renewable fuel with standard fuel to meet renewable volume obligations (“RVOs”). Obligated Parties can comply with RVOs by either blending RNG into their existing fuel supply or purchasing Renewable Identification Numbers, or RINs. RINs are generated when eligible renewable fuels are produced or imported and blended with a petroleum product for use as a transportation fuel. The RFS program has been a key driver of growth in the RNG industry since 2014 when the EPA ruled that RNG, when used as a transportation fuel, would qualify for D3 RINs (for cellulosic biofuels), which are generally the most valuable among the four categories of RINs. In 2023, we estimate that we generated 47% of all D3 RINs in the U.S.

The monetization of RNG also benefits from low-carbon fuel initiatives at the state-level, specifically from established programs in California, Oregon and Washington. California’s LCFS (“CA LCFS”) program requires fuel producers and importers to reduce the carbon intensity (“CI”) of their products, with goals of a 10% reduction in carbon emissions from 1990 levels by 2020 and a 20% reduction by 2030. CARB awards CA LCFS credits to RNG projects based on each project’s CI score relative to the target CI score for gasoline and diesel fuels. The CI score represents the overall net impact of carbon emissions for each RNG pathway and is determined on a project-by-project basis. Because our business involves the capture and transformation of waste methane into a renewable source of energy, our customers are able to significantly reduce, if not eliminate, GHG emissions from their commercial transportation activities. Further, CARB calculates RNG produced by livestock farms as carbon negative, generating substantial incremental CA LCFS credits. Multiple other states, including New York and New Mexico are considering LCFS initiatives like those implemented in California, Oregon and Washington. In 2023, we estimate that we generated 44% of all LCFS credits under Bio-CNG and Bio-LNG pathways in the CA LCFS.

Our Strategy

We aim to maintain and increase our position as the leading provider of RNG to the commercial vehicle market in North America, and our goal is to deliver 100% RNG to our entire fueling infrastructure by 2025. We support this objective through a multi-pronged strategy of:

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Promoting the reduction of methane emissions and expanding the use of renewable fuels to displace fossil-based fuels.

We share the renewable fuel industry’s commitment to provide sustainable renewable energy solutions and to offer products with high economic and ecological value. By simultaneously replacing fossil-based fuels and reducing overall methane emissions, our business has a substantial positive environmental impact. We are committed to the sustainable development, deployment, and utilization of RNG to reduce the country’s dependence on fossil fuels. In addition to its methane emission benefits, the increased production and use of RNG have several other environmental benefits. Anaerobically digested livestock waste produces significantly less odor than conventional storage and land application systems. The odor of stored livestock waste mainly comes from volatile organic acids and hydrogen sulfide, which has a “rotten egg” smell. In an anaerobic digester, volatile organic compounds are reduced to methane and carbon dioxide, which are odorless gases. The volatized fraction of hydrogen sulfide is captured with the collected ADG and destroyed. Anaerobic digestion provides several water quality and land conservation benefits as well. Digesters, particularly heated digesters, can destroy more than 90% of disease-causing bacteria that might otherwise enter surface waters and pose a risk to human and animal health. Digesters also reduce biochemical oxygen demand (“BOD”). BOD is one measure of the potential for organic wastes to reduce dissolved oxygen in natural waters. Because fish and other aquatic organisms need minimum levels of dissolved oxygen for survival, farm practices that reduce BOD protect the health of aquatic ecosystems. In addition to protecting local water resources, implementing anaerobic digesters on livestock facilities improves soil health. Adding digestate to soil increases the organic matter content, reduces the need for chemical fertilizers, improves plant growth and alleviates soil compaction. Further, digestion converts nutrients in manure to a more accessible form for plants to use. The risks of water and soil contamination from flooding of open lagoons are also mitigated by digesters.

Increasing supply of RNG through the development of new project investment opportunities, expanding our existing supplier portfolio, and leveraging our extensive fueling station network and customer relationships.

In our view, the market has not yet unlocked the full potential of RNG. We believe we were the first company to deliver RNG to the commercial vehicle fuels market, have the most extensive RNG fueling infrastructure and customer relationships, and our stations and customer relationships allow us to obtain and deliver substantially more RNG to vehicle operators than any other participant in the market. This is important because RNG must be placed in vehicle fuel tanks to generate the valuable Environmental Credits.

Dependable and economic sources of RNG are critical to our success. We continue to leverage our relationships built over the past several decades to identify and execute new RNG project development and supply offtake opportunities. These come from our relationships with feedstock owners and project developers who value our long operating history, strong reputation in the industry and unmatched access to fueling infrastructure and vehicle operators for certainty of Environmental Credit generation. Based on the foregoing, we believe that we are presented with nearly every material development, supply and distribution opportunity in the market.

We exercise financial discipline in pursuing projects by targeting project returns that are in line with the relative risk of the specific projects and associated feedstock costs and any related attributes that can be monetized. We also support third parties that own RNG production facilities by entering into long-term RNG supply offtake agreements. As these facility owners expand their operations, we provide additional access to our fueling infrastructure and customer relationships.

As of December 31, 2023, we obtain RNG from over 100 supply sources. We believe that we have one of the largest and most diverse supply portfolios in the RNG industry, which allows us to provide certainty of RNG supply to our vehicle operator customers.

In our view, all the foregoing gives us a competitive advantage relative to existing and new market entrants.

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Empowering our customers to achieve their sustainability and carbon reduction objectives.

In November 2023, global leaders met in Dubai, United Arab Emirates for the United Nations Climate Change Conference (“COP28”) to discuss the world’s efforts to address climate change under the Paris Agreement. With evidence indicating that the world community may fall short of limiting the Paris Agreement’s target of global warming to less than 1.5°C, governments and regulators globally responded with a decision on how to accelerate actions across all areas by 2030, including a call on governments to speed up the transition away from traditional fossil fuels to renewables. There is pressure from politicians, regulators, non-governmental organizations and the investment community directed at corporations to sharpen focus on credible, net-zero aligned transition plans, and key investors have made climate change risk management a key priority.

We believe we are uniquely positioned to empower our customers to achieve their sustainability and carbon reduction goals. Because our business involves the capture and transformation of waste methane into a renewable source of energy, we believe our customers can significantly reduce, if not eliminate, GHG emissions from their commercial transportation activities. Further, our RNG is available today to reduce climate harming GHG and meet sustainability objectives and at a cost to customers that is very competitive to other fuels like diesel. We also assist our customers in their transition to cleaner transportation fuels by helping them obtain federal, state and local tax credits, grants and incentives, providing vehicle financing, including through our Zero Now and Chevron Adopt-A-Port programs, engineering and constructing fueling stations, and facilitating customer selection of vehicle specifications that best meet their needs.

Management expertise

Our management team has decades of combined experience in the alternative vehicle fueling industry. We believe our team’s proven track record in alternative vehicle fuels and focus on RNG gives us a strategic advantage in continuing to grow our business profitably. Our diverse experience and integration of key technical, environmental, and administrative support functions, along with our first-to-market advantage, further our ability to successfully deliver RNG to the commercial vehicle fuels market.

Environmental, health and safety and compliance leadership

Our executive team places the highest priority on the health and safety of our staff and third parties, as well as the preservation of the environment. Our corporate culture is built around supporting these priorities, as reflected in our well-established practices and policies. By setting and maintaining high standards in the renewable energy field, we are often able to contribute positively to the safety practices and policies of our partners and customers. Our high safety standards include use of wireless gas monitoring safety devices, active monitoring of all field workers, performing environmental health and safety (“EHS”) audits and using technology throughout our safety processes from employee training in compliance with operational processes and procedures to emergency preparedness. By extension, we incorporate our EHS standards into our subcontractor selection qualifications to ensure that our commitment to high EHS standards is shared by our subcontractors. For 2023, our Total Recordable Incident Rate (“TRIR”) was 1.89, which is lower than the 2022 national average of 3.0 TRIR for all industries. As of December 31, 2023, we have not received any U.S. Occupational Health and Safety Administration (“OSHA”) or state OSHA citations in the last five years.

How We Generate Revenue

We generate revenue from selling RNG and conventional natural gas as a vehicle fuel, as well as by selling the associated Environmental Credits. RNG made up 89% of our vehicle fuel sales in 2023, and we expect 100% of our vehicle fuel sales to be RNG by 2025. Although RNG has the same chemical composition as natural gas from fossil sources, it has unique Environmental Credits assigned to it due to its origin from low- and negative-carbon, renewable sources. The Environmental Credits that we sell are composed of RINs and state low-carbon fuel credits, including CA LCFS credits, which are generated from the conversion of biogas to RNG that is used as a transportation fuel.

In addition to revenues generated from sales of RNG and conventional natural gas as a vehicle fuel and Environmental Credits, we also generate revenues by providing O&M services for public and private RNG, natural gas and hydrogen vehicle fleet customer stations; selling and servicing compressors and other equipment used in RNG production and at RNG, natural gas and hydrogen stations; and obtaining federal, state and local tax credits, grants and incentives.

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We are experts in the engineering, design and construction of fueling stations. When we build stations for customers, we charge construction, other fees, or lease rates based on the size and complexity of the project. Since 2008, we have served as the general contractor or supervised qualified third-party contractors to build over 460 fueling stations.

Key Customer Markets

We serve customers in a variety of markets, including trucking, airports, refuse and public transit. We believe these customer markets are well-suited for the adoption of RNG and other alternative vehicle fuels because they consume relatively high volumes of fuel, refuel at centralized locations or along well-defined routes and/or are facing increasingly stringent emissions or other environmental requirements. During the years ended December 31, 2021, 2022 and 2023, no single customer accounted for 10% or more of our total revenue.

Trucking

We believe heavy-duty trucking represents the greatest opportunity for RNG and other alternatives to be used as a vehicle fuel. We estimate there are approximately 4.1 million Class 8 heavy-duty trucks operating in the U.S. using over 40 billion gallons of fuel each year. Because these high-mileage vehicles consume substantial amounts of fuel, operators can derive significant benefits from the carbon and GHG reductions associated with our vehicle fuels. We are focused on fueling more heavy-duty trucks, and many well-known shippers, manufacturers, retailers and other truck fleet operators have started to use RNG fueled trucks to move their freight, including, among others, Amazon, Pepsi Frito-Lay, FedEx, Anheuser-Busch, USPS, UPS, Kroger, KeHe Distributors, Kenan Advantage Group, and Estes Express.

Zero Now

To help facilitate the transition of trucking fleets to our fuels, we have launched the Zero Now truck financing program, which is intended to increase the deployment of the commercially available RNG heavy-duty trucks in the U.S. The Zero Now program generally involves the following:

We previously entered into the following agreements to implement the Zero Now program:

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In addition, we are supporting the growth of the RNG heavy-duty truck market through commodity swap arrangements under which we have locked in a discount price to diesel for customers fueling with us; our negotiation of favorable fuel tank pricing from manufacturers, which we are passing along to our customers; and our network of truck-friendly fueling stations (we refer to this network as “America’s Natural Gas Highway” or “ANGH”), which we have built in key locations nationwide. Many existing ANGH stations are located at Pilot Travel Centers, the largest truck fueling operator in the U.S.

Chevron Adopt-A-Port Program

In 2020, we partnered with Chevron Products Company, a division of Chevron U.S.A. Inc (“Chevron”) on Adopt-A-Port, an initiative that provides truck operators serving the ports of Los Angeles and Long Beach with RNG to reduce emissions. For its part, Chevron provides funding for Adopt-A-Port and supplies RNG to Clean Energy stations near the ports. Chevron’s funding allows truck operators to subsidize the cost of buying new RNG-powered trucks. We manage the program, including offering fueling services for qualified truck operators. Truck operators participating in the program, which supports the ports’ Clean Trucks Program and Clean Air Action Plan, fuel at our stations supplied with Chevron RNG. Importantly, Adopt-A-Port provides a meaningful air quality improvement for the adversely impacted communities around the port – such communities typically have the worst air quality in the nation. In 2023, customers contracted 95 trucks under Adopt-A-Port, and we expect 96 additional trucks to be ordered in 2024.

Airports

We estimate that vehicles serving airports in the U.S., including airport delivery fleets, rental car and parking passenger shuttles and taxis, consume an aggregate of approximately two billion gallons of fuel per year. Additionally, many U.S. airports face emissions challenges and are under regulatory directives and political pressure to reduce pollution, particularly as part of any expansion plans. As a result, many of these airports have adopted various strategies to address tailpipe emissions, including rental car and hotel shuttle consolidation and requiring or encouraging service vehicle operators to switch their fleets to our vehicle fuels.

Refuse

We believe that there are nearly 200,000 refuse trucks in the U.S. that collect and haul refuse and recyclables, which aggregately consume approximately two billion gallons of fuel per year. We estimate that approximately 60% of new refuse trucks are capable of operating on RNG, up from approximately 3% of new refuse trucks in 2008. Refuse haulers are increasingly adopting trucks that run on our vehicle fuels to realize operational savings and to address demands for reduced emissions from the public, investors, and governmental agencies. As of December 31, 2023, we fuel approximately 16,000 refuse vehicles for customers including Waste Management, Republic Services, Waste Connections, GFL Environmental, Atlas Disposal, Burrtec, CR&R, Recology and Waste Pro, among others. We also provide vehicle fueling services to municipal refuse fleets.

Public Transit

We believe that there are over 72,000 municipal transit buses operating in the U.S. In many areas, increasingly stringent emissions standards have limited the fueling options available to public transit operators. Also, transit agencies typically fuel at a central location and use high volumes of fuel. We estimate that transit agencies in the U.S. consume approximately one billion gallons of fuel per year. Many transit agencies have been early adopters of vehicles using our

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fuels, and approximately 30% of existing transit buses and approximately 35% of new transit buses can operate on RNG. As of December 31, 2023, public transit customers for which we serve include the Los Angeles County Metropolitan Transit Authority, New York MTA, Foothill Transit (Los Angeles County, California), Orange County Transit Authority, Santa Monica Big Blue Bus, Dallas Area Rapid Transit, Phoenix Transit, New Jersey Transit, Jacksonville Transportation Authority, NICE Bus (Nassau County, New York) and Washington Metro Area Transportation Authority.

Competition

There are many other companies operating in the renewable energy and waste-to-energy space. Regarding RNG production and supply, our primary competition is from other companies or solutions for access to biogas from waste. Evolving customer preferences, regulatory conditions, ongoing waste industry trends, and project economics have a strong effect on the competitive landscape. We have demonstrated a track record of strategic flexibility across our history which has allowed us to pivot towards projects and markets that we believe deliver optimal returns and stockholder value in response to changes in market, regulatory and competitive pressures. The biogas and RNG markets are heavily fragmented. We believe we are in a strong position to compete for new project development and supply opportunities. Competition for such opportunities, however, including the prices being offered for fuel supply, affect the profitability of the opportunities we pursue, and may make opportunities unsuitable to pursue.

The market for vehicle fuels is highly competitive. The biggest competition for RNG use as a vehicle fuel is diesel because most vehicles in our key markets are powered by this fuel. Many established businesses are in the market for RNG and other alternatives for use as vehicle fuel, including alternative vehicle and alternative fuel companies, refuse collectors, industrial gas companies, truck stop and fuel station owners, fuel providers, utilities and their affiliates and other organizations. We also compete with suppliers of other alternative vehicle fuels, including renewable diesel, biodiesel and ethanol, as well as producers and fuelers of alternative vehicles, including hybrid, electric and hydrogen-powered vehicles. Additionally, our stations compete directly with other natural gas fueling stations and indirectly with electric vehicle charging stations and fueling stations for other vehicle fuels. In addition, we transport and sell CNG through NG Advantage’s virtual natural gas pipelines and interconnects and compete with other participants in this market.

If the alternative vehicle fuel market grows then the number and type of participants in this market and their level of capital and commitments to alternative vehicle fuel programs will increase. We compete for vehicle fuel users based on demand for the type of fuel, which may be affected by a variety of factors, including, among others, cost, supply, availability, quality, cleanliness, and safety of the fuel; cost, availability and reputation of vehicles and engines; convenience and accessibility of fueling stations; regulatory mandates and other requirements; and recognition of the brand. We believe we compare favorably with our competitors based on these factors; however, some of our competitors have substantially greater financial, marketing, and other resources than we have. As a result, these competitors may be able to respond more quickly to changes in customer preferences, legal requirements or other industry or regulatory trends; devote greater resources to the development, promotion and sale of their products; adopt more aggressive pricing policies, dedicate more effort to infrastructure and systems development in support of their business or product development activities; implement more robust or creative initiatives to advance customer acceptance of their products; or exert more influence on the regulatory landscape that impacts the vehicle fuels market.

Governmental Regulation

We are subject to a variety of federal, state and local laws and regulations relating to the environment, health and safety, labor and employment, building codes and construction, zoning and land use, the government procurement process, any political activities or lobbying in which we may engage, public reporting and taxation, among others. Many of these laws and regulations are complex, change frequently and have become more stringent over time. Any changes to existing regulations, adoption of new regulations or failure by us to comply with applicable regulations may result in significant additional expense to us or to our customers or a variety of administrative, civil, and criminal enforcement measures, any of which could have a material adverse effect on our business, reputation, financial condition and results of operations. Certain regulations that significantly affect our various operating activities are described below. Compliance with these regulations has not had a material effect on our capital expenditures, earnings, or competitive position to date, but new regulations or amendments to existing regulations to make them more stringent could have such an effect in the future. We cannot estimate the expenses we may incur to comply with potential new laws or changes to existing laws, or the other

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potential effects these laws may have on our business, and these unknown costs and effects are not specifically contemplated by our existing customer agreements or our budgets and cost estimates.

We are subject to federal, state, and local air quality, solid waste, and water quality regulations and permitting requirements. Specific construction and operating permit requirements may differ among states. Specific permits we frequently must obtain include air permits, nonhazardous waste management permits, pollutant discharge elimination permits, and beneficial use permits. We must also maintain compliance with relevant federal, state and local environmental, health and safety requirements.

RNG projects are subject to federal RFS program regulations. The EPA administers the RFS program with volume requirements for several categories of renewable fuels. The EPA’s RFS regulations establish rules for fuel supplied and administer the RIN system for compliance, trading credits and rules for waivers. The EPA calculates a blending standard for each year based on estimates of gasoline usage from the Department of Energy’s Energy Information Agency. Separate quotas and blending requirements are determined for cellulosic biofuels, biomass-based diesel, advanced biofuels, and total renewable fuel. Further, we are required to register each RNG project with the EPA and relevant state regulatory agencies. We qualify our RINs through a voluntary Quality Assurance Plan, which typically takes from three to five months from first injection of RNG into the commercial pipeline system. Further, we may make a large project investment prior to receiving the regulatory approval and RIN qualification. In addition to registering each RNG project, we are subject to quarterly audits under the Quality Assurance Plan of our projects to validate our qualification.

Our operations are also subject to state renewable fuel standard regulations. The CA LCFS program requires producers of petroleum-based fuels to reduce the CI of their products, which began with a quarter of a percent in 2011 to a 10% total reduction by 2020, and a 20% total reduction by 2030. Petroleum importers, refiners and wholesalers can either develop their own low-carbon fuel products or buy CA LCFS credits from other companies that develop and sell low-carbon alternative fuels, such as biofuels, electricity, natural gas, or hydrogen. We are subject to a qualification process like that for RINs, including verification of CI levels and other requirements existing for CA LCFS credits.

Before an RNG project can be developed, all Resource Conservation and Recovery Act (“RCRA”) Subtitle D requirements (requirements for nonhazardous solid waste management) must be satisfied. In particular, because methane is explosive in certain concentrations and poses a hazard if it migrates, biogas collection systems must meet RCRA Subtitle D standards for gas control. RNG projects may be subject to other federal, state and local regulations that impose requirements for nonhazardous solid waste management.

Certain of our operations may be subject to federal requirements to prepare for and respond to spills or releases from tanks and other equipment and provide training on operation, maintenance and discharge prevention procedures and the applicable pollution control laws. We may be required to develop spill prevention, control and countermeasure plans to memorialize our preparation and response plans and to update them on a regular basis.

Our operations may result in liability for hazardous substances or other materials placed into soil or groundwater. Pursuant to the Comprehensive Environmental Response, Compensation and Liability Act of 1980 or other federal, state, or local laws governing the investigation and cleanup of sites contaminated with hazardous substances, we may be required to investigate and/or remediate soil and groundwater contamination at our projects, contiguous and adjacent properties and other properties owned and/or operated by third parties.

Additionally, biogas projects may need to obtain National Pollutant Discharge Elimination System permits if wastewater is discharged directly to a receiving water body. If wastewater is discharged to a local sewer system, biogas projects may need to obtain an industrial wastewater permit from a local regulatory authority for discharges to a Publicly Owned Treatment Works. The authority to issue these permits may be delegated to state or local governments by the EPA. The permits, which typically last five years, limit the quantity and concentration of pollutants that may be discharged. Permits may require wastewater treatment or impose other operating conditions to ensure compliance with the limits. In addition, the Clean Water Act and implementing state laws and regulations require individual permits or coverage under general permits for discharges of storm water runoff from certain types of facilities.

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On September 23, 2020, the California Governor issued an Executive Order N-79-20 setting goals for expanding the sale and use of zero-emission vehicles within California, including 100% of in-state sales of new passenger cars and trucks to be zero-emission by 2035, and 100% of medium- and heavy-duty truck vehicles in California to be zero-emission by 2045 for all operations where feasible. The Governor also directed CARB to develop and propose regulations to achieve these goals consistent with state and federal law. This order is the latest in a series of targets set by California to transform the energy and transportation fuel sectors and reduce GHG emissions. Executive Order B55-18 sets a statewide target to achieve carbon neutrality no later than 2045. The transitioning of California’s energy markets to increased reliance on renewable and carbon-free sources has the potential to create favorable market conditions for RNG but could also harm our vehicle fueling business. Future regulatory actions will be required to meet the state’s zero-emission and carbon neutrality targets.

Employees and our Human Capital

As of December 31, 2023, we employed 566 people. We have not experienced any work stoppages, and none of our employees are subject to collective bargaining agreements.

The success and growth of our business is significantly correlated with our ability to recruit, train, promote and retain talented individuals at all levels of our organization. To succeed in a competitive labor market, we have developed and maintain key recruitment and retention strategies. These include competitive salary structures, including bonus compensation programs, and competitive benefits policies, including paid time off for vacations, sick leave and holidays, short-term disability coverage, group term life insurance, and various retirement savings and incentive plans.

We are committed to increasing diversity, equity, and inclusion in all areas of our company. It is important that we build and maintain a diverse and inclusive workforce and leadership team that is reflective of the communities in which we operate. We also strive to promote diversity on our Board of Directors. Currently, two of our nine directors are female, and one of our nine directors identify as being members of an ethnic minority.

Safety of our personnel is a core value of Clean Energy and maintaining a safe work environment is critical to an energy company’s ability to attract and retain employees.

Sales and Marketing

We market our brands, products and services primarily through our direct sales force, which includes sales representatives covering all of our major geographic and customer markets, as well as attendance at trade shows and participation in industry conferences and events. Our sales and marketing team also work closely with federal, state and local government agencies to provide education about the value of our vehicle fuels and to keep abreast of proposed and newly adopted regulations that affect our industry.

Seasonality

To some extent, our business may experience seasonality. For more information, see the discussion under “Seasonality and Inflation” in Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

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Intellectual Property

Our intellectual property rights primarily consist of trade secrets, patents, know-how and trademarks, and we rely on a combination of trademark laws, trade secret laws, confidentiality provisions and other contractual provisions to protect these rights and our proprietary information. These intellectual property rights help us to retain existing business and secure new relationships with customers.

We have a total of 13 issued patents currently active, including 10 patents issued by the United States Patent and Trademark Office (“USPTO”) and 3 patents issued by the Canadian Intellectual Property Office (“CIPO”), expiring between 2027 and 2036. Additionally, we have 13 registered trademarks, including 10 trademarks registered with the USPTO and 3 trademarks registered with the CIPO, expiring between 2024 and 2032, and 2 trademark applications pending, including 1 trademark application filed with the USPTO and 1 trademark application filed with the CIPO.

More Information

Our website is located at www.cleanenergyfuels.com. We make available, free of charge on our website, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. The SEC maintains a website at www.sec.gov that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC, including us. All references to our website in this report are inactive textual references, and the contents of our website are not incorporated into this report.

Item 1A. Risk Factors

An investment in our Company involves a high degree of risk of loss. You should carefully consider the risk factors discussed below and all of the other information included in this report before you make any investment decision regarding our securities. We believe the risks and uncertainties described below are the most significant we face, but additional risks and uncertainties not known to us or that we currently deem immaterial could also be or become significant. The occurrence of any of these risks could harm our business, financial condition, results of operations, prospects and reputation and could cause the trading price of our common stock to decline.

Risks Related to Our Business

Our success is dependent on the willingness of fleets and other customers to adopt our vehicle fuels, which may not occur in a timely manner, at expected levels or at all.

Our success is highly dependent on the adoption by fleets and other customers of our RNG and conventional natural gas vehicle fuels. The market for our vehicle fuels has experienced slow, volatile and unpredictable growth in many sectors. For example, adoption and deployment of our vehicle fuels in heavy-duty trucking has been slower and more limited than we anticipated. Also, other important fleet markets, including airports and public transit, had slower volume and customer growth in recent years that may continue. If the market for our vehicle fuels does not develop at improved rates or levels, or if a market develops but we are not able to capture a significant share of the market or the market subsequently declines, our business, prospects, financial condition, and operating results would be harmed.

Factors that may influence the adoption of our vehicle fuels, many of which are beyond our control, include, among others: lack of demand for trucks that use our vehicle fuels; adoption or expansion of government policies, programs, funding or incentives, or increased publicity or popular sentiment in favor of vehicles or fuels other than RNG and natural gas, including long-standing support for diesel-powered vehicles, changes to emissions requirements applicable to vehicles and fleets powered by diesel, RNG, natural gas, or other vehicle fuels and/or growing support for electric and hydrogen-powered vehicles; limitations on the capabilities of utilities to provide services to meet our requirements. For example, natural gas utilities may be unable to expand piping or provide services for new expansions, and electric utilities may lack the capacity to provide service for our projects; perceptions about the benefits of our vehicle fuels relative to diesel and other alternative vehicle fuels, including with respect to factors such as supply, cost savings, environmental benefits and

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safety; increases, decreases or volatility in the supply, demand, use and prices of crude oil, diesel, RNG, natural gas and other vehicle fuels, such as electricity, hydrogen, renewable diesel, biodiesel and ethanol; inertia among fleets and fleet vehicle operators, who may be unable or unwilling to prioritize converting a fleet to our vehicle fuels over an operator’s other general business concerns, particularly if the operator is not sufficiently incentivized by emissions regulations or other requirements or lacks demand for the conversion from its customers, drivers, or other stakeholders; vehicle cost, fuel efficiency, availability, quality, safety, convenience (to fuel and service), design, performance and residual value, as well as operator perception with respect to these factors, generally and in our key customer markets and relative to comparable vehicles powered by other fuels; the development, production, cost, availability, performance, sales and marketing and reputation of engines that are well-suited for the vehicles used in our key customer markets, including heavy-duty trucks and other fleets; increasing competition in the market for vehicle fuels generally, and the nature and effect of competitive developments in this market, including improvements in or perceived advantages of other vehicle fuels and engines powered by these fuels; the impact of federal or state laws, orders or regulations mandating new or additional limits on GHG emissions, “tailpipe” emissions or internal combustion engines, including the Advanced Clean Trucks regulation, the September 2020 Executive Order, the Advanced Clean Fleets regulation and the 2021 Executive Order (each as defined below); the availability and effect of environmental, tax or other government regulations, programs or incentives that promote our products or other alternatives as a vehicle fuel, including certain programs under which we generate credits by selling RNG as a vehicle fuel, as well as the market prices for such credits; and emissions and other environmental regulations and pressures on producing, transporting, and dispensing our fuels.

In addition, as our customers and partners react to economic conditions and the potential for a global recession, they may reduce spending and take additional precautionary measures to limit or delay expenditures and preserve capital and liquidity. Reductions in spending, delays in purchasing decisions, lack of renewals, inability to attract new customers, uncertainty about business continuity as well as pressure for extended billing terms or pricing discounts, could limit our ability to grow our business and negatively affect our operating results and financial condition.

We are dependent on the production of vehicles and engines in our key customer and geographic markets by manufacturers, over which we have no control.

Vehicle and engine manufacturers control the development, production, quality assurance, cost and sales and marketing of their products, which shapes the performance, availability and reputation of these products in the marketplace. We are dependent on these manufacturers to succeed in our target markets, and we have no influence or control over their activities. A small number of manufacturers, chiefly Cummins, produce engines that use our vehicle fuels. The number of manufacturers making vehicles that use our fuels is limited as well. These manufacturers may decide not to expand or maintain, or may decide to discontinue or curtail, their engine or vehicle product lines for a variety of reasons, including as a result of the adoption of government policies or programs such as the Advanced Clean Trucks regulation, the September 2020 Executive Order and the Advanced Clean Fleets regulation. The limited production of engines and vehicles that use our fuels increases their cost and limits availability, which restricts large-scale adoption, and may reduce resale value, which may contribute to operator reluctance to convert their fleets to vehicles that use our fuels. In addition, some operators have communicated to us that earlier models of heavy-duty truck engines using our fuels have a reputation for unsatisfactory performance, and that this reputation or their first-hand experiences of such performance may be a factor in operator decisions regarding whether to convert their fleets to vehicles that use our fuels. If manufactures of vehicles and engines that use our fuels develop unsatisfactory vehicles or engines, then our business, financial condition, and results of operations may be adversely affected.

Our RNG business may not be successful.

Our RNG business consists of procuring RNG from projects we plan to develop and own or from projects owned by third-party producers and reselling this RNG through our fueling infrastructure. The success of our RNG business depends on our ability to secure, on acceptable terms, a sufficient supply of RNG; sell this RNG in adequate volumes and at prices that are attractive to customers and produce acceptable margins for us; and sell Environmental Credits we may generate under applicable federal or state programs from our sale of RNG as a vehicle fuel at favorable prices as well as our ability to appropriately balance supply we take with demand from customers. Our ability to maintain an adequate supply of RNG is subject to risks affecting RNG production, including unpredictable production levels or other difficulties due to, among others, problems with equipment, severe weather, droughts, financial condition of the applicable ADG and LFG source

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owner, health crises and pandemics, construction delays, technical difficulties, high operating costs, limited availability, unfavorable composition of collected feedstock gas, and plant shutdowns caused by upgrades, expansion or required maintenance. Our ability to balance supply with demand from customers is subject to risk where we are committed to acquire RNG produced by third-party producers that could exceed the level of demand of our customers. If we are unable to maintain an adequate supply of RNG or are oversupplied with RNG versus customer demand,  our business, financial condition, and performance could be negatively affected. In addition, increasing demand for RNG will result in more robust competition for supplies of RNG, including from other vehicle fuel providers, gas utilities and other users and providers. If we or any of our RNG suppliers experience these or other difficulties in RNG production processes, or if competition for RNG development projects and supply increases, then our supply of RNG and our ability to resell it as a vehicle fuel could be jeopardized.

Our ability to generate revenue from our sale of RNG or our generation and sale of Environmental Credits depends on many factors, including the markets for RNG as a vehicle fuel and for Environmental Credits. The markets for Environmental Credits have been volatile and unpredictable in recent periods, and the prices for these credits are subject to fluctuations. Additionally, the value of Environmental Credits, and consequently the revenue levels we may receive from our sale of these credits, may be adversely affected by changes to the federal and state programs under which these credits are generated and sold, prices for and use of oil, diesel or gasoline, the inclusion of additional qualifying fuels in the programs, increased production and use of other fuels in the programs, or other conditions. Our ability to generate revenue from sales of Environmental Credits depends on our strict compliance with these federal and state programs, which are complex and can involve a significant degree of judgment. If the agencies that administer and enforce these programs disagree with our judgments, otherwise determine we are not in compliance, conduct reviews of our activities or make changes to the programs, then our ability to generate or sell these credits could be restricted, permanently limited, or lost entirely, and we could also be subject to fines or other sanctions. Any of these outcomes could force us to purchase credits in the open market to cover any credits we have contracted to sell, retire credits we may have generated but not yet sold, reduce or eliminate a significant revenue stream, or incur substantial additional and unplanned expenses. Any permanent or temporary discontinuation or suspension of federal and state programs that provide credits, grants and incentives, such as the AFTC, would also adversely impact our revenue. Moreover, in the absence of programs that allow us to generate and sell Environmental Credits or other federal and state programs that support the RNG vehicle fuel market, or if our customers are not willing to pay a premium for RNG, we may be unable to operate our RNG business profitably or at all.

Our commercial success depends on our ability and the ability of our third-party supply sources to successfully develop and operate projects and produce expected volumes of RNG.

Our specific focus on RNG exposes us to risks related to the supply of and demand for RNG and Environmental Credits, the cost of capital expenditures, government regulation, and economic conditions, among other factors. As an RNG supplier we may also be negatively affected by lower RNG production resulting from lack of feedstock, mechanical breakdowns, faulty technology, competitive markets, or changes to the laws and regulations that mandate the use of renewable energy sources.

In addition, other factors related to the development and operation of renewable energy projects could adversely affect our business, including: (i) changes in pipeline gas quality standards or other regulatory changes that may limit our ability to transport RNG on pipelines for delivery to vehicles or increase the costs of processing RNG to allow for such deliveries; (ii) construction risks, including the risk of delay, that may arise because of inclement weather, natural disasters, accidents, labor disruptions, disputes, or increases in costs for or shortages of equipment and construction materials; (iii) operating risks; (iv) weather conditions; (v) financial condition of the applicable source owner; (vi) health of the applicable dairy herd; (vii) consolidation in the dairy industry; (viii) budget overruns; (ix) possible liabilities because of unforeseen environmental, construction, technological or other complications; (x) failures or delays in obtaining desired or necessary rights, including leases and feedstock agreements; and (xi) failures or delays in obtaining and keeping in good standing permits, authorizations and consents from local city, county, state and U.S. federal governments as well as local and U.S. federal governmental organizations. Any of these factors could prevent completion or operation of projects, or otherwise adversely affect our business, financial condition, and results of operations.

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Acquisition, financing, construction, and development of projects by us or our partners that own projects and divestitures, investments or other strategic relationships, may not commence on anticipated timelines or at all, may not meet expectations, and may otherwise harm our business.

Our strategy is to continue to expand, including through the acquisition of additional projects and by signing additional supply agreements with third-party project owners. From time to time, we and our partners enter into nonbinding letters of intent for projects. Until the negotiations are final, however, and the parties have executed definitive documentation, we or our partners may not be able to consummate any development or acquisition transactions, or any other similar arrangements, on the terms set forth in the applicable letter of intent or at all. The acquisition, financing, construction and development of projects involves numerous risks, including: the ability to obtain financing for a project on acceptable terms or at all; difficulties in identifying, obtaining, and permitting suitable sites for new projects; failure to obtain all necessary rights to land access and use; inaccuracy of assumptions with respect to the cost and schedule for completing construction; inaccuracy of assumptions with respect to the biogas potential, including quality, volume, and asset life; delays in deliveries or increases in the price of equipment; permitting and other regulatory issues, license revocation and changes in legal requirements; increases in the cost of labor, labor disputes and work stoppages; potential business or financial stress of partners; failure to receive quality and timely performance of third-party or utility services; unforeseen engineering and environmental problems; cost overruns; accidents involving personal injury or the loss of life; and weather conditions, catastrophic events, including fires, explosions, earthquakes, droughts and acts of terrorism, and other force majeure events.

Additionally, we may acquire or invest in other companies or businesses or pursue other strategic transactions or relationships, such as joint ventures, collaborations, divestitures, or other similar arrangements. These strategic transactions and relationships and any others we may pursue in the future involve numerous risks, any of which could harm our business, performance and liquidity, including, among others, the following: (i) difficulties integrating the operations, personnel, contracts, service providers and technologies of an acquired company or partner; (ii) diversion of financial and management resources from existing operations or other opportunities; (iii) failure to realize the anticipated synergies or other benefits of a transaction or relationship; (iv) risks of entering new customer or geographic markets in which we may have limited or no experience; (v) potential loss of our or an acquired company’s or partner’s key employees, customers, vendors or assets in the event of an acquisition or investment; and (vi) incurrence of substantial costs or debt or equity dilution to fund an acquisition, investment or other transaction or relationship, as well as possible write-offs or impairment charges relating to any businesses we partner with, invest in or acquire. Further, our partners, including TotalEnergies, bp and Chevron, may reallocate their resources from RNG to other renewable or low carbon vehicle fuels. Any such action would have a material adverse effect on our plans, results of operations and financial condition.

To secure ADG RNG from new projects we develop, we typically face a long and variable development cycle that requires significant resource commitments and a long lead time before we realize revenue.

The development, design and construction process for ADG RNG projects generally lasts between 12 to 24 months on average. Prior to entering into a letter of intent with respect to an ADG RNG project, we typically conduct a preliminary assessment of whether the site is commercially viable based on our expected return on investment, investment payback period, and other operating metrics, as well as whether the necessary permits to develop a project on that site are available. After entering into a project letter of intent, we perform a more detailed review of the site’s facilities, including a life-cycle assessment, which serves as the basis for the final specifications of the project. Finally, we negotiate and execute contracts with the site owner and other parties. This extended development process requires the dedication of significant time and resources from our personnel, with no certainty of success or recovery of our expenses. Further, upon commencement of operations, it takes about 15-18 months for the project to ramp up to expected production level, receive necessary registrations and approvals from the EPA and CARB, and begin generating revenue. All these factors, and in particular, expenditures on development of projects that will not generate significant revenue in the near term, can contribute to fluctuations in our financial performance and increase the likelihood that our operating results in a particular period will fall below investor expectations.

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Livestock waste and dairy farm projects are dependent on LCFS credits and RINS.

Livestock waste and dairy farm projects are heavily dependent on the LCFS credits and, to a lesser extent, RINs for commercial viability. If CARB reduces the CI score that it applies to waste conversion projects, such as dairy digesters, the number of LCFS credits for RNG generated at livestock waste and dairy farm projects will decline. Additionally, revenue from LCFS credits also depends on the price per LCFS credit. LCFS credit prices are driven by various market forces, including the supply of and demand for LCFS credits, which depends on the demand for traditional and other renewable fuels and mandated CI targets, which determine the number of LCFS credits required to offset LCFS deficits. Fluctuations in the price of LCFS credits or the number of LCFS credits assigned will significantly affect the success of our livestock waste and dairy farm projects. RINs and LCFS Credit prices have fluctuated in recent years and will likely continue to be volatile. A significant decline in the value of LCFS credits could adversely affect our business, financial condition, and results of operations.

We have a history of losses and may incur additional losses in the future.

We have incurred pre-tax losses in the past, may incur losses in the future, and may never sustain profitability, any of which would adversely affect our business, prospects and financial condition and may cause the price of our common stock to fall. Furthermore, historical losses may not be indicative of future losses, and our future losses may be greater than our past losses. In addition, to try to achieve or sustain profitability, we may choose or be forced to take actions that result in material costs or material asset or goodwill impairments. For instance, we have recorded significant charges in connection with our closure of certain fueling stations, our determination that certain assets were impaired because of the foregoing, and other actions. We review our assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset or asset group may not be recoverable, and we perform a goodwill impairment test on an annual basis and between annual tests in certain circumstances, in each case in accordance with applicable accounting guidance and as described in the financial statements and related notes included in this report. Changes to the use of our assets, divestitures, changes to the structure of our business, significant negative industry or economic trends, disruptions to our operations, inability to effectively integrate any acquired businesses, further market capitalization declines, or other similar actions or conditions could result in additional asset impairment or goodwill impairment charges or other adverse consequences, any of which could have material negative effects on our financial condition, our results of operations and the trading price of our common stock.

Our plans for hydrogen and electric vehicle stations will require significant cash investments and management resources and may not meet our expectations.

As operators deploy hydrogen powered vehicles, we plan to modify our fueling stations to reform our RNG, build additional hydrogen stations, and deliver clean hydrogen. Further, we have the capability to add electric charging at our sites, and we believe our RNG can be used to generate clean electricity to power vehicles. Our plans will require significant cash investments and management resources and may not meet our expectations with respect to additional sales of our vehicle fuels. We have experience constructing hydrogen fueling stations, but such facilities cost significantly more than traditional RNG vehicle fueling stations. In addition, we have not yet added electric charging capability to any of our stations, and the cost of such capability may be significant. We will need to ensure compliance with all applicable regulatory requirements, including obtaining any required permits and land use rights, which could take considerable time and expense and is subject to the risk that government support in certain areas may be discontinued. If we are unable to modify our stations to provide hydrogen or add electric charging to our stations, or if we experience delays in doing so, our stations may be unable to meet our customer demand, which may negatively impact our business, prospects, financial condition, and operating results. Additionally, even if we are able to successfully modify our stations to provide hydrogen or electric charging stations, we will be dependent on the manufacturers of hydrogen and electric vehicles to succeed in our target markets, and we will have no influence over their activities. See the risks discussed under “We are dependent on the production of vehicles and engines in our key customer and geographic markets by original equipment manufacturers, over which we have no control,” above and elsewhere in these risk factors.

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Increases, decreases and general volatility in oil, diesel, renewable diesel,  natural gas, RNG and Environmental Credit prices could adversely affect our business.

The prices of RNG, natural gas, crude oil, diesel, renewable diesel, and Environmental Credits can be volatile, and this volatility may continue to increase. Factors that may cause volatility in the prices of RNG, natural gas, crude oil, diesel, renewable diesel, and Environmental Credits include, among others, changes in supply and availability of crude oil, RNG and other renewable transportation fuels, and natural gas, government regulations, inventory levels, customer demand, price and availability of alternatives, weather conditions, negative publicity about crude oil or natural gas drilling, production or transportation techniques and methods, worldwide economic, military, health and political conditions, transportation costs and the price of foreign imports. If the prices of crude oil and diesel are low or decline, or if the price of RNG or natural gas increases without corresponding increases in the prices of crude oil and diesel or Environmental Credits, we may not be able to offer our customers an attractive price for our vehicle fuels, market adoption of our vehicle fuels could be slowed or limited and/or we may be forced to reduce the prices at which we sell our vehicle fuels in order to try to attract new customers or prevent the loss of demand from existing customers. Natural gas and crude oil prices are expected to remain volatile for the near future because of market uncertainties over supply and demand, including due to the state of the world economy, geopolitical conditions, military conflicts such as the wars in Ukraine and the Middle East, energy infrastructure and other factors. Fluctuations in natural gas prices affect the cost to us of the natural gas commodity. High natural gas prices adversely affect our operating margins when we cannot pass the increased costs through to our customers. Conversely, lower natural gas prices reduce our revenue when the commodity cost is passed through to our customers.

Pricing conditions may also exacerbate the cost differential between vehicles that use our fuels and diesel-powered vehicles, which may lead operators to delay or refrain from purchasing or converting to our vehicle fuels. Generally, vehicles that use our fuels cost more initially than diesel-powered vehicles because the components needed for a vehicle to use our fuels add to the vehicle’s base cost. Operators then seek to recover the additional base cost over time through a lower cost to use our fuels. Operators may, however, perceive an inability to timely recover these additional initial costs if our vehicle fuels are not available at prices sufficiently lower than diesel. Such an outcome could decrease our potential customer base and harm our business prospects.

We face increasing competition from competitors, many of which have far greater resources, customer bases and brand awareness than we have, and we may not be able to compete effectively with these businesses.

The market for vehicle fuels is highly competitive. The biggest competition for our products is diesel because most vehicles in our key markets are powered by these fuels. We also compete with suppliers of other alternative vehicle fuels, including renewable diesel, biodiesel, and ethanol, as well as producers and fuelers of alternative vehicles, including hybrid, electric and hydrogen-powered vehicles. Additionally, our stations compete directly with other natural gas fueling stations and indirectly with electric vehicle charging stations and fueling stations for other vehicle fuels. Many businesses are in the market for RNG and other alternatives for use as vehicle fuel, including alternative vehicle and alternative fuel companies, refuse collectors, industrial gas companies, private equity groups, commodity traders, truck stop and fuel station owners, fuel providers, gas marketers, utilities and their affiliates and other organizations. If the alternative vehicle fuel market grows, the number and type of participants in this market and their level of capital and other commitments to alternative vehicle fuel programs could increase. Many of our competitors have substantially greater customer bases, brand awareness and financial, marketing and other resources than we have. As a result, these competitors may be able to respond more quickly to changes in customer preferences, legal requirements or other industry or regulatory trends; devote greater resources to the development, promotion and sale of their products; adopt more aggressive pricing policies; dedicate more effort to infrastructure and systems development in support of their business or product development activities; implement more robust or creative initiatives to advance customer acceptance of their products; or exert more influence on the regulatory landscape that affects the vehicle fuels market. We expect competition to increase in the vehicle fuels market generally. In addition, if the demand for alternative vehicle fuels, including RNG, increases, then we expect competition to also increase. Any such increased competition may reduce our customer base and revenue and may lead to increased pricing pressure, reduced operating margins and fewer expansion opportunities.

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We rely on information technology in our operations, and any material failure, inadequacy, interruption, or security failure of that technology could harm our business.

Increased global cybersecurity threats and more sophisticated and targeted computer crime pose a risk to the security of our information systems and the confidentiality, availability and integrity of our data. There have been several recent, highly publicized cases in which organizations of various types and sizes have reported the unauthorized disclosure of customer or other confidential information, as well as cybersecurity incidents involving the dissemination, theft and destruction of corporate information, intellectual property, cash or other valuable assets. There have also been several highly publicized cases in which hackers have requested “ransom” payments in exchange for not disclosing customer or other confidential information or for not disabling the target company’s computer or other systems. Implementing security measures designed to prevent, detect, mitigate or correct these or other cybersecurity threats involves significant costs. Although we have taken steps to protect the security of our information systems and the data maintained in those systems, we have, from time to time, experienced cyberattacks or other cybersecurity incidents that have threatened our data and information systems, including malware and computer virus attacks and it is possible that future cybersecurity incidents we may experience may materially and adversely affect our business. We cannot provide assurance that our safety and security measures will prevent our information systems from improper functioning or damage, or the improper access or disclosure of personally identifiable information such as in the event of cybersecurity incidents. Any IT security threats that are successful against our security measures could, depending on their nature and scope, lead to the compromise of confidential information, improper use of our systems and networks, manipulation and destruction of data, operational disruptions, and substantial financial outlays. Further, a cybersecurity incident could occur and persist for an extended period of time without detection, and an investigation of any successful cybersecurity incident would likely require significant time, costs and other resources to complete. We may be required to expend significant financial resources to protect against or to remediate such cybersecurity incidents. In addition, our information technology infrastructure and information systems are vulnerable to damage or interruption from natural disasters, power loss and telecommunications failures. Any failure to maintain proper function, security and availability of our information systems and the data maintained in those systems could interrupt our operations, damage our reputation, subject us to liability claims or regulatory penalties, harm our business relationships or increase our security and insurance costs, which could have a material adverse effect on our business, financial condition and results of operations.

NG Advantage may not be successful.

NG Advantage provides “virtual pipelines” to transport CNG by truck from compression facilities to pipeline interconnects and to industrial and commercial customer users that do not have direct access to natural gas pipelines. NG Advantage faces unique risks, including among others: (i) it has a history of net losses and has incurred substantial indebtedness; (ii) NG Advantage may need to raise additional capital, which may not be available, may only be available on onerous terms, or may only be available from the Company; (iii) the labor market for truck drivers is very competitive, which increases NG Advantage’s difficulty in meeting its delivery obligations; (iv) NG Advantage often transports CNG in trailers over long distances and these trailers may be involved in accidents; and (v) NG Advantage’s CNG trailers may become subject to new or changed regulations that could adversely affect its business. If NG Advantage fails to manage any of these risks, our business, financial condition, liquidity, results of operations, prospects and reputation may be harmed. In addition, we have been a significant source of financing for NG Advantage. If NG Advantage needs to raise additional capital and is not able to obtain financing from external sources, we may need to provide additional debt or equity capital to allow NG Advantage to satisfy its commitments and maintain operations.

Our station construction activities subject us to business and operational risks.

As part of our business activities, we design and construct vehicle fueling stations that we either own and operate ourselves or sell to our customers. These activities require a significant amount of judgment in determining where to build and open fueling stations, including predictions about fuel demand that may not be accurate for any of the locations we target. As a result, we have built stations that we may not open for fueling operations, and we may open stations that fail to generate the volume or profitability levels we anticipate, either or both of which could occur due to a lack of sufficient customer demand at the station locations or for other reasons. For any stations that are completed but unopened, we would have substantial investments in assets that do not produce revenue, and for any stations that are open and underperforming, we may decide to close the stations. For example, we have several nearly completed stations that are not open for fueling

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operations. We do not know when or if these stations will open, and some of these stations are subject to agreements that may expire prior to us being able to open such stations. Closure of these and/or any other stations could result in substantial additional costs and non-cash asset impairments or other charges and could cause the price of our common stock to decline.

We also face many operational challenges in connection with our station design and construction activities. For example, we may not be able to identify suitable locations for the stations we or our customers seek to build. Additionally, even if preferred sites can be located, we may encounter land use or zoning difficulties, problems with utility services, challenges obtaining and retaining required permits and approvals or local resistance, including due to reduced operations of permitting agencies because of health crises, any of which could prevent us or our customers from building new stations on these sites or limit or restrict the use of new or existing stations. Any such difficulties, resistance or limitations or any failure to comply with local permit, land use or zoning requirements could restrict our activities or expose us to fines, reputational damage or other liabilities, which would harm our business and results of operations. In addition, we act as the general contractor and construction manager for new station construction and facility modification projects, and we typically rely on licensed subcontractors to perform the construction work. We may be liable for any damage we or our subcontractors cause or for injuries suffered by our employees or our subcontractors’ employees during the course of work on our projects. Additionally, shortages of skilled subcontractor labor could significantly delay a project or otherwise increase our costs. Further, our expected profit from a project is based in part on assumptions about the cost of the project, and cost overruns, delays or other execution issues may, in the case of projects we complete and sell to customers, result in our failure to achieve our expected margins or cover our costs, and in the case of projects we build and own, result in our failure to achieve an acceptable rate of return. If any of these events occur, our business, operating results and liquidity could be negatively affected.

We have significant contracts with government entities, which are subject to unique risks.

We have, and expect to continue to seek, long-term fueling station construction, maintenance and fuel sale contracts with various government bodies, which accounted for 31%, 27% and 30% of our revenue in 2021, 2022 and 2023, respectively. In addition to normal business risks, including the other risks discussed in these risk factors, our contracts with government entities are often subject to unique risks, some of which are beyond our control. For example, long-term government contracts and related orders are subject to cancellation if adequate appropriations for subsequent performance periods are not made. Further, the termination of funding for a government program supporting any of our government contracts or any other governmental action that results in reduced support for our government contracts could result in the loss of anticipated future revenue attributable to the contract. Moreover, government entities with which we contract are often able to modify, curtail or terminate contracts with us at their convenience and without prior notice, and would only be required to pay for work completed and commitments made at or prior to the time of termination.

In addition, government contracts are frequently awarded only after competitive bidding processes, which are often protracted. In many cases, unsuccessful bidders for government contracts are provided the opportunity to formally protest the contract awards through various agencies or other administrative and judicial channels. The protest process may substantially delay a successful bidder’s contract performance, result in cancellation of the contract award entirely and distract management. As a result, we may not be awarded contracts for which we bid, and substantial delays or cancellation of contracts may follow any successful bids as a result of any protests by other bidders. The occurrence of any of these risks would have a material adverse effect on our results of operations and financial condition.

Our results of operations fluctuate significantly and are difficult to predict.

Our results of operations have historically experienced, and may continue to experience, significant fluctuations as a result of a variety of factors, including, among others, the amount and timing of our vehicle fuel sales, Environmental Credit sales and recognition of government credits, station construction sales, grants and incentives, such as AFTC (for example, we recorded all of the AFTC revenue associated with our vehicle fuel sales made in the first and second quarters of 2022 during the third quarter of 2022); fluctuations in commodity, station construction and labor costs; fluctuations in expenditures and resource commitments due to new ADG RNG project developments; variations in the fair value of certain of our derivative instruments that are recorded in revenue; sales of compressors and other equipment used in RNG production and at fueling stations; the amount and timing of our billing, collections and liability payments; and the other factors described in these risk factors.

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Our performance in certain periods has also been affected by transactions or events that have resulted in significant cash or non-cash gains or losses. These or other similar gains or losses may not recur, in the same amounts or at all in future periods. These significant fluctuations in our operating results may render period-to-period comparisons less meaningful, especially with respect to periods heavily impacted by effects of the COVID-19 pandemic, and investors in our securities should not rely on the results of one period as an indicator of performance in any other period. Additionally, these fluctuations in our operating results could cause our performance in any period to fall below the financial guidance we may have provided to the public or the estimates and projections of the investment community, which could negatively affect the price of our common stock.

The COVID-19 pandemic has and may continue to adversely affect, and a future pandemic or epidemic may adversely affect, our business, results of operations and financial condition.

Our business has been and may continue to be adversely affected by the COVID-19 pandemic. For example, as a result of the COVID-19 pandemic, we experienced increased costs on equipment and construction services, and longer lead times on equipment and materials orders. Any future pandemic, epidemic, or infectious disease outbreak could also adversely affected our business through delaying the adoption of our RNG and natural gas vehicle fuels by heavy-duty trucks and/or a delaying increased usage of our vehicle fuels; decreasing the volume of truck and fleet operations, including shuttle buses at airports, and public transportation generally, and disrupting production of vehicles and engines that use our fuels. Any of the foregoing may result in decreased demand for our vehicle fuels, plant closures, decreased manufacturing capacity, and delays in deliveries, which would negatively impact our business, operations, and financial condition.

Our future success will depend on our ability to attract and retain qualified management, technical, and other personnel.

Our future success is dependent on the services and performance of our executive officers and other key management, engineering, information technology, scientific, manufacturing and operating personnel. The loss of the services of any such personnel could materially adversely affect our business. Our ability to achieve our strategic plans will also depend on our ability to attract and retain additional qualified personnel. Recruiting key personnel in our industry is highly competitive and we cannot assure you that we will be able to do so. Our inability to attract and retain additional qualified personnel, or the departure of key employees, could materially and adversely affect our strategic plans and, therefore, our business, results of operations and financial condition. In addition, our inability to attract and retain sufficient personnel to quickly increase production at our facilities when and if needed to meet increased demand may adversely impact our ability to respond rapidly to any new product, growth or revenue opportunities.

Risks Related to Our Indebtedness and Other Capital Resources.

We may need to raise additional capital to continue to fund our business, which could have negative effects and may not be available when needed, on acceptable terms or at all.

We require capital to pay for capital expenditures, operating expenses, any mergers, acquisitions or strategic investments, capital calls related to our joint ventures, transactions or relationships we may pursue, and to make principal and interest payments on our indebtedness. If we cannot fund any of these activities with capital on-hand or cash provided by our operations, we may seek additional capital from other sources, such as by selling assets or pursuing debt or equity financing.

Asset sales and equity or debt financing may not be available when needed, on terms favorable to us or at all. Any sale of our assets to generate cash proceeds may limit our operational capacity and could limit or eliminate any revenue streams or business plans that are dependent on the sold assets. Any issuances of our common stock or securities convertible into our common stock to raise capital would dilute the ownership interest of our existing stockholders. Any debt financing we may pursue could require us to make significant interest or other payments and to pledge some or all of our assets as security. In addition, higher levels of indebtedness could increase our risk of non-repayment, adversely affect our creditworthiness, and amplify the other risks associated with our existing debt, which are discussed elsewhere in these risk factors. Further, we may incur substantial costs in pursuing any capital-raising transactions, including investment

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banking, legal and accounting fees. On the other hand, if we are unable to obtain capital in amounts sufficient to fund our obligations, expenses, and strategic initiatives, we could be forced to suspend, delay or curtail our business plans or operating activities or could default on our contractual commitments. Any such outcome could negatively affect our business, performance, liquidity, and prospects.

Our indebtedness could adversely affect our financial condition or operating flexibility and prevent us from fulfilling our obligations under our credit agreement and other indebtedness we may incur, and we may not generate sufficient cash flow from our business to pay our debt.

On December 12, 2023, we and our wholly-owned direct subsidiary Clean Energy entered into a senior secured first lien term loan agreement (the “Credit Agreement”) with the lenders from time to time party thereto (“Lenders”) and Stonepeak CLNE-L Holdings LP (“Stonepeak”), as the administrative agent and collateral agent for the Lenders and collateral agent for the secured parties, pursuant to which the Lenders funded a $300,000,000 senior secured term loan and committed to making an additional $100,000,000 of delayed draw term loans available for the two-year period after closing. As of December 31, 2023, we had total consolidated indebtedness of $264.8 million, net of debt discount, and we may incur additional debt in the future. Our outstanding and any future indebtedness could make us more vulnerable to adverse changes in general U.S. and worldwide economic, including rising interest rates, regulatory, and competitive conditions, limit our flexibility to plan for or react to changes in our business or industry, place us at a disadvantage compared to our competitors that have less debt, or limit our ability to borrow or otherwise raise additional capital as needed.

Our payments of amounts owed under our various debt instruments will reduce our cash resources available for other purposes, including pursuing strategic initiatives, transactions or other opportunities, satisfying our other commitments, and generally supporting our operations. Moreover, our ability to make these payments depends on our future performance, which is subject to economic, financial, competitive and other factors, including those described in these risk factors, and many of which are beyond our control. Our business may not generate sufficient cash from operations to service our debt. If we cannot meet our debt obligations from our operating cash flows, we may pursue one or more alternative measures. Any repayment of our debt with equity, however, would dilute the ownership interests of our existing stockholders. We are permitted under the Credit Agreement to incur additional debt under certain conditions. If new debt were to be incurred in the future, the related risks that we now face could intensify. The Credit Agreement requires us and our subsidiaries, on a consolidated basis, to comply with a maximum total net leverage ratio, a minimum interest coverage ratio, and a minimum liquidity test. In addition, the Credit Agreement contains certain covenants that limit or restrict our and our subsidiaries’ ability to incur liens, incur indebtedness, dispose of assets, make investments, make certain restricted payments, merge or consolidate, amend our charter documents and certain other agreements, and enter into speculative hedging arrangements. In the event of any default on our debt obligations, the holders of the indebtedness could, among other things, declare all amounts owed immediately due and payable and foreclose on our assets that serve as collateral. Any such declaration could deplete all or a large portion of our available cash flow, and thereby reduce the amount of cash available to pursue our business plans or force us into bankruptcy or liquidation.

Our warranty reserves may not adequately cover our warranty obligations, which could result in unexpected costs.

We provide product warranties with varying terms and durations for the stations we build and sell, and we establish reserves for the estimated liability associated with these warranties. Our warranty reserves are based on historical trends and any specifically identified warranty issues known to us, and the amounts estimated for these reserves could differ materially from the warranty costs we may actually incur. We would be adversely affected by an increase in the rate or volume of warranty claims or the amounts involved in warranty claims, any of which could increase our costs beyond our established reserves and cause our cash position and financial condition to suffer.

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Risks Related to Environmental Health and Safety and Governmental and Environmental Regulations

Our business is influenced by environmental, tax and other government regulations, programs and incentives that promote our vehicle fuels, and their modification or repeal could negatively affect our business.

Our business is influenced by federal, state, and local tax credits, rebates, grants and other government programs and incentives that promote or exclude the use of our vehicle fuels. These include various government programs that make grant funds available from the purchase of vehicles and construction of fueling stations, as well as the AFTC under which we generate revenue for our vehicle fuel sales. Additionally, our business is influenced by laws, rules and regulations that require reductions in carbon emissions and/or the use of renewable fuels, such as the programs under which we generate Environmental Credits.

These programs and regulations, which have the effect of encouraging the use of RNG as a vehicle fuel, could expire or be repealed or amended for a variety of reasons. For example, parties with an interest in gasoline and diesel, electric or other alternative vehicles or vehicle fuels, including lawmakers, regulators, policymakers, environmental or advocacy organizations, producers of alternative vehicles or vehicle fuels, or other powerful groups, may invest significant time and money in efforts to delay, repeal or otherwise negatively influence regulations and programs that promote RNG. Many of these parties have substantially greater resources and influence than we have. Further, changes in federal, state or local political, social or economic conditions, including as a result of a lack of legislative focus on these programs and regulations or prolonged U.S. government shutdown, could result in their modification, delayed adoption or repeal. For example, the IRA contains credits and tax incentives that may be beneficial to us but interagency guidance processes are still ongoing. Any failure to adopt, delay in implementing, expiration, repeal or modification of these programs and regulations, or the adoption of any programs or regulations that encourage the use of other alternative fuels or alternative vehicles over RNG, could reduce the market for RNG as a vehicle fuel and harm our operating results, liquidity, and financial condition.

To benefit from Environmental Credits, RNG projects are required to be registered and are subject to audit.

RNG projects are required to register with the EPA and relevant state regulatory agencies. Further, we qualify our RINs through a voluntary Quality Assurance Plan, which typically takes from three to five months from first injection of RNG into the commercial pipeline system. We also must certify RNG pathways with CARB, which typically takes from 15-18 months from first injection of RNG into the commercial pipeline system. Delays in obtaining registration, RIN qualification, and any LCFS credit qualification of a new project could delay future revenues from a project and could adversely affect our cash flow. Further, we may make large investments in projects prior to receiving the regulatory approval and RIN qualification. By registering RNG projects with the EPA’s voluntary Quality Assurance Plan and by establishing RNG pathways under CARB’s LCFS program, we are subject to third-party audits and on-site visits of projects to validate generated RINs and overall compliance with the federal renewable fuel standard and the LCFS. We are also subject to a separate third party’s annual attestation review. The Quality Assurance Plan provides a process for RIN owners to follow, for an affirmative defense to civil liability, if used or transferred Quality Assurance Plan verified RINs were invalidly generated. A project’s failure to comply could result in remedial action, including penalties, fines, retirement of RINs, or termination of the project’s registration, any of which could adversely affect our business, financial condition and results of operations.

Our business could be negatively affected by federal or state laws, orders or regulations mandating new or additional limits on GHG emissions, “tailpipe” emissions or internal combustion engines.

Federal or state laws, orders or regulations have been adopted, such as California’s AB 32 cap and trade law, and may in the future be adopted that impose limits on GHG emissions or otherwise require the adoption of zero-emission electric vehicles. The effects of GHG emission limits on our business are subject to significant uncertainties based on, among other things, the timing of any requirements, the required levels of emission reductions, the nature of any market-based or tax-based mechanisms adopted to facilitate reductions, the relative availability of GHG emission reduction offsets, the development of cost-effective, commercial-scale carbon capture and storage technology and supporting regulations and liability mitigation measures, the range of available compliance alternatives, and our ability to demonstrate that our vehicle fuels qualify as a compliance alternative under any statutory or regulatory programs to limit GHG emissions. If our vehicle

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fuels are not able to meet GHG emission limits or perform as well as other alternative fuels and vehicles, our solutions could be less competitive. Furthermore, additional federal or state taxes could be implemented on “tailpipe” emissions or on methane emissions generally, which would have a negative impact on the cost of our vehicle fuels, as compared to vehicle fuels that do not generate tailpipe emissions.

In June 2020, CARB adopted the Advanced Clean Trucks regulation, which requires manufacturers to sell a gradually increasing proportion of zero-emission electric trucks, vans and pickup trucks from 2024 onwards. By the year 2045, the Advanced Clean Trucks regulation seeks to have every new commercial vehicle sold in California be zero-emissions. Further, in September 2020, the Governor of the State of California issued an executive order (the “September 2020 Executive Order”) providing that it shall be the goal of California that (i) 100% of in-state sales of new passenger cars and trucks will be zero-emission by 2035, (ii) 100% of medium- and heavy-duty vehicles in California will be zero-emission by 2045 for all operations, where feasible, and by 2035 for drayage trucks, and (iii) the state will transition to 100% zero-emission off-road vehicles and equipment by 2035 where feasible. The September 2020 Executive Order also directed CARB to develop and propose regulations and strategies aimed at achieving the foregoing goals. Resulting regulations mandate increasing adoption of zero-emission vehicles. In April 2023, CARB adopted the Advanced Clean Fleets regulation, which requires all truck fleets be zero emission by 2042. The Advanced Clean Fleets regulation also seeks to end the sale of combustion trucks in California in 2036. Among other things, we believe the intent of the Advanced Clean Trucks regulation, the September 2020 Executive Order, and the Advanced Clean Fleets regulation is to limit and ultimately discontinue the production and use of internal combustion engines because such engines have “tailpipe” emissions. Implementation of such regulations and executive actions may slow, delay or prevent the adoption by fleets and other commercial customers of our vehicle fuels, particularly in California. Moreover, other states have taken steps to enact similar regulations, which may slow, delay, change, or prevent the adoption of our vehicle fuels in those states as well. These actions could result in state funding and incentive programs being directed only to the adoption of zero emission vehicles. In December 2021, President Biden signed an executive order (the “2021 Executive Order”) that directs the federal government to achieve certain goals, including purchasing 100% zero-emission vehicles by 2035 for its fleet of over 600,000 cars and trucks.

Our business is subject to a variety of government regulations, including environmental regulations, which may restrict our operations and result in costs and penalties or otherwise adversely affect our business and ability to compete.

We are subject to a variety of federal, state and local laws and regulations relating to the environment, health and safety, labor and employment, building codes and construction, zoning and land use, the government procurement process, any political activities or lobbying in which we may engage, public reporting and taxation, among others. It is difficult and costly to manage the requirements of every authority having jurisdiction over our various activities and to comply with their varying standards. Many of these laws and regulations are complex, change frequently, may be unclear and difficult to interpret and have become more stringent over time. Any changes to existing regulations, adoption of new regulations, or judicial rulings regarding such regulations, may result in significant additional expense to us or our customers. For example, our operations are and will be subject to federal, state and local environmental laws and regulations, including laws relating to the use, handling, storage, disposal of and human exposure to hazardous materials. Contamination at properties we own or operate, will own or operate, or formerly owned or operated to which hazardous substances were sent by us, are subject to the Comprehensive Environmental Response, Compensation and Liability Act, which can impose liability for the full amount of remediation-related costs without regard to fault, for the investigation and cleanup of contaminated soil and ground water, for impacts to human health and for damages to natural resources.

Further, from time to time, as part of the regular evaluation of our operations, including newly acquired or developing operations, we may be subject to compliance audits by regulatory authorities, which may distract management from our revenue-generating activities and involve significant costs and use of other resources. Also, we often need to obtain facility permits or licenses to address, among other things, storm water or wastewater discharges, waste handling and air emissions in connection with our operations, which may subject us to onerous or costly permitting conditions or delays if permits cannot be timely obtained. Our failure to comply with any applicable laws and regulations could result in property damage, bodily injury or a variety of administrative, civil and criminal enforcement measures, including, among others, assessment of monetary penalties, imposition of corrective requirements, including cleanup costs, or prohibition from providing services to government entities. If any of these enforcement measures were imposed on us, our business, financial condition, and performance could be negatively affected.

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Our operations entail inherent safety and environmental risks, which may result in substantial liability to us.

Our operations entail inherent safety risks, including risks associated with equipment defects, malfunctions, failures, and misuses. For example, operation of LNG pumps requires special training because of the extremely low temperatures of LNG. Also, LNG tanker trailers and CNG fuel tanks and trailers could rupture if involved in accidents or improper maintenance or installation. Further, improper refueling of vehicles that use our fuels or operation of vehicle fueling stations could result in sudden releases of pressure that could cause explosions. In addition, our operations may result in the venting of methane, which is flammable and is a potent GHG. These safety and environmental risks could result in uncontrollable flows of our fuels, fires, explosions, death, or serious injury, any of which may expose us to liability for personal injury, wrongful death, property damage, pollution and other environmental damage. We may incur substantial liability and costs if any such damages are not covered by insurance or are more than policy limits, or if environmental damage causes us to violate applicable GHG emissions or other environmental laws. Additionally, the occurrence of any of these events with respect to our fueling stations or our other operations could materially harm our business and reputation. Moreover, the occurrence of any of these events to any other organization in our vehicle fuel business could harm our industry generally by negatively affecting perceptions about, and adoption levels of, our vehicle fuels.

Risks Related to Our Common Stock

A significant portion of our outstanding common stock is owned or otherwise subject to acquisition by three equityholders, each of which may have interests that differ from the Company’s other stockholders and which now or in the future may be able to influence the Company’s corporate decisions, including a change of control.

After giving effect to the issuance of the Amazon Warrant and the Stonepeak Warrant (defined below), Total Marketing Services, SAS (“TMS”), a wholly owned subsidiary of TotalEnergies, owns approximately 19% of our outstanding shares of common stock as of December 31, 2023. In addition, TotalEnergies was granted certain special rights that our other stockholders do not have in connection with its acquisition of this ownership position, including the right to designate two individuals to serve as directors of our Company and a third individual to serve as an observer on certain of our board committees.

The Amazon Warrant was immediately exercisable by Amazon Holdings for 4.999% of our outstanding common stock when issued. Subject to additional vesting through fuel purchase from the Company pursuant to the Fuel Agreement, the Amazon Warrant will be exercisable for up to 19.999% of our outstanding common stock on a fully diluted basis (determined at the time of issuance), subject to certain anti-dilution provisions, and Amazon Holding’s beneficial ownership will initially be contractually limited to the beneficial ownership limitation unless Amazon Holdings gives the Company sixty one (61) days’ notice that it is waiving such limitation.

The Stonepeak Warrant is exercisable at any time after December 12, 2025 for up to 9.999% of our common stock outstanding immediately after giving effect to such exercise, and Stonepeak’s beneficial ownership will initially be contractually limited to such beneficial ownership limitation unless Stonepeak gives the Company sixty one (61) days’ notice that it is waiving such limitation.

TotalEnergies or other current or future large stockholders may be able to influence or control matters requiring approval by our stockholders, including the election of directors, mergers and acquisitions, or other extraordinary transactions. Large stockholders may have interests that differ from other stockholders and may vote or otherwise act in ways with which the Company or other stockholders disagree or that may be adverse to your interests. A concentration of stock ownership may also have the effect of delaying, preventing or deterring a change of control of our Company, which could deprive our stockholders of an opportunity to receive a premium for their shares of our common stock as part of a sale of our Company and could affect the market price of our common stock. Conversely, such a concentration of stock ownership may facilitate a change of control under terms other stockholders may not find favorable or at a time when other stockholders may prefer not to sell.

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Sales of our common stock, or the perception that such sales may occur, could cause the market price of our stock to drop significantly, regardless of the state of our business.

All outstanding shares of our common stock are eligible for sale in the public market, subject in certain cases to the requirements of Rule 144 under the Securities Act. Also, shares of our common stock that may be issued upon the exercise, vesting or conversion of our outstanding stock options and restricted stock units may be eligible for sale in the public market, to the extent permitted by Rule 144 and the provisions of the applicable stock option and restricted stock unit agreements or if such shares have been registered under the Securities Act. Sales of large amounts of our common stock by large stockholders, or the perception that such sales may occur, could cause the market price of our common stock to decline, regardless of the state of the Company’s business. Our common stock held by TMS, our common stock underlying the Amazon Warrant, and our common stock underlying the Stonepeak Warrant may be sold in the public market under Rule 144 or in registered sales or offerings pursuant to registration rights held by each stockholder. If these shares are sold, or if it is perceived that they may be sold, in the public market, the trading price of our common stock could decline.

The price of our common stock may continue to fluctuate significantly, and you could lose all or part of your investment.

The market price of our common stock has experienced, and may continue to experience, significant volatility. Factors that may cause volatility in the price of our common stock, many of which are beyond our control, include, among others, the following: (i) the factors that may influence the adoption of our vehicle fuels, as discussed elsewhere in these risk factors; (ii) our ability to implement our business plans and initiatives and their anticipated, perceived or actual level of success; (iii) failure to meet or exceed any financial guidance we have provided to the public or the estimates and projections of the investment community; (iv) the market’s perception of the success and importance of any of our acquisitions, divestitures, investments or other strategic relationships or transactions; (v) the amount and timing of sales of, and prices for, Environmental Credits; (vi) actions taken by state or federal governments to mandate or otherwise promote or incentivize alternative vehicles or vehicle fuels over, or to the exclusion of, RNG; (vii) technical factors in the public trading market for our common stock that may produce price movements that may or may not comport with macro, industry or company-specific fundamentals, including, without limitation, the sentiment of retail investors (including as may be expressed on financial trading and other social media sites), the amount and status of short interest in our common stock, access to margin debt, and trading in options and other derivatives on our common stock; (viii) changes in political, regulatory, health, economic and market conditions; and (ix) a change in the trading volume of our common stock.

In addition, the securities markets have from time-to-time experienced significant price and volume fluctuations that are unrelated to the operating performance of particular companies, but which have affected the market prices of these companies’ securities. These market fluctuations may also materially and adversely affect the market price of our common stock. Volatility or declines in the market price of our common stock could have other negative consequences, including, among others, further impairments to our assets, potential impairments to our goodwill and a reduced ability to use our common stock for capital-raising, acquisitions or other purposes. The occurrence of any of these risks could materially and adversely affect our financial condition, results of operations and liquidity and could cause further declines in the market price of our common stock.

Item 1B.   Unresolved Staff Comments.

None.

Item 1C.   Cybersecurity.

We maintain an information security program as part of our enterprise-wide risk management system. Our information security program is managed by our Group Vice President, whose portfolio includes top level oversight of information technology, information security and IT risk management. The Group Vice president is responsible, along with his team, for leading company-wide cybersecurity strategy, policy, standards, architecture, and processes. Our Group Vice President has served in that role since 2012 and has been in cybersecurity related roles for 25 years. Our Group Vice President and IT Director provide periodic updates to our Board of Directors, Audit Committee, and other senior management members. These updates include, among other risk management issues, updates on the Company’s cybersecurity risks and threats,

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the status of projects to strengthen our information security systems, assessments of the information security program, and the emerging threat landscape.

Our program is regularly evaluated by internal and external experts with the results of those reviews reported to the Board of Directors, Audit Committee, and senior management. We also collaborate with thought leaders in cybersecurity including with key vendors, business partners, cybersecurity and data breach response counsel, and industry participants as part of our continuing efforts to evaluate and improve the effectiveness of our information security policies and procedures. This collaboration allows us to rapidly adopt industry best practices developed through firsthand experience mitigating cyber incidents.

When reviewing potential threats or cybersecurity incidents, our Board of Directors has delegated the authority to the Audit Committee to setup crisis incident management teams comprised of senior management and appropriate specialists. These crisis incident management teams report on an as needed basis to the Audit Committee and full Board of Directors to keep them informed and seek direction where necessary.

We are not aware of any risks from cybersecurity threats, including as a result of any cybersecurity incidents, which have materially affected or are reasonably likely to materially affect our company, including our business strategy, results of operations, or financial condition. Refer to “Item 1A. Risk Factors” in this annual report on Form 10-K, including “We rely on information technology in our operations, and any material failure, inadequacy, interruption, or security failure of that technology could harm our business,” for additional discussion about cybersecurity-related risks.

Item 2.   Properties.

Our corporate headquarters are located at 4675 MacArthur Court, Suite 800, Newport Beach, California 92660, where we occupy approximately 48,000 square feet of office space. Our lease for this facility expires in June 2028.

We own and operate the Boron Plant in Boron, California, approximately 125 miles from Los Angeles. In November 2006, we entered into a 30-year ground lease for the 36 acres on which this plant is situated. The Boron Plant can produce 56.0 million gallons of LNG per year and has a dual tanker trailer loading system and a 1.8 million gallon storage tank that can hold up to 1.5 million usable gallons. The plant had a production utilization rate of 79% and 78% for the years ended December 31, 2022 and 2023, respectively.

We own and operate the Pickens Plant located in Willis, Texas, approximately 50 miles north of Houston. We own approximately 24 acres of land on which this plant is situated, along with approximately 34 acres surrounding the plant. The Pickens Plant can produce 28.0 million gallons of LNG per year and includes a tanker trailer loading system and a 1.0 million gallon storage tank that can hold up to 840,000 usable gallons. The plant had a production utilization rate of 62% for the year ended December 31, 2022. During the year ended December 31, 2023, the Pickens Plant was offline for maintenance and repairs; hence, the plant had no LNG production in 2023.

We own, operate or supply 579 fueling stations in the U.S. and 24 in Canada. Fueling stations are facilities where RNG or conventional natural gas is dispensed in the form of CNG or LNG into the fuel tanks of vehicles for use as transportation fuel. We own station equipment throughout the U.S. (See Note 10) that is used for dispensing CNG or LNG at properties we lease under long-term lease arrangements (See Note 16). Additionally, we operate fueling stations or supply CNG or LNG to fueling stations where our customer owns the fueling station equipment. At these stations, we operate under the following arrangements: (i) provide O&M services on a per gallon or fixed fee basis and do not directly sell CNG or LNG, or (ii) provide O&M services and also have a fuel supply sales agreement for CNG or LNG with our customer.

Item 3.   Legal Proceedings.

From time to time, we may become involved in various legal proceedings that arise in the ordinary course of our business, including lawsuits, claims, audits, government enforcement actions and related matters. It is not possible to predict when or if these proceedings may arise, nor is it possible to predict the outcome of any proceedings that do arise, including, among other things, the amount or timing of any liabilities we may incur, and any such proceedings could have

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a material effect on us regardless of outcome. In the opinion of management, however, we are not a party, and our properties are not subject, to any pending legal proceedings that are material to us.

Item 4.   Mine Safety Disclosures.

None.

PART II

Item 5.   Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Market Information

Our common stock trades on The Nasdaq Global Select Market under the symbol “CLNE.”

Holders

There were approximately 52 holders of record of our common stock as of February 22, 2024. The actual number of holders of our common stock is greater than this number of record holders and includes stockholders who are beneficial owners, but whose shares are held in street name by brokers or held by other nominees.

Issuer Purchases of Equity Securities

On March 12, 2020, our Board of Directors approved a share repurchase program of up to $30.0 million (exclusive of fees and commissions) of our outstanding common stock (the “Repurchase Program”). On December 7, 2021, our Board of Directors approved an increase in the aggregate amount of our common stock to be repurchased under the Repurchase Program from $30.0 million to $50.0 million (exclusive of fees and commissions). The Repurchase Program does not have an expiration date, and may be suspended or discontinued at any time. As of December 31, 2023, approximately $26.5 million remained available under the Repurchase Program.

The Repurchase Program does not obligate us to acquire any specific number of shares. Repurchases under the Repurchase Program may be effected from time to time through open market purchases, privately negotiated transactions, structured or derivative transactions, including accelerated share repurchase transactions, or other methods of acquiring shares, in each case subject to market conditions, applicable securities laws and other relevant factors. Repurchases may also be made under plans set up pursuant to Rule 10b5-1 promulgated under the Exchange Act.

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The following table summarizes the Company’s share repurchase activities during the three months ended December 31, 2023 (in thousands, except share and per share amounts):

​

Performance Graph

This performance graph shall not be deemed “soliciting material” or “filed” with the SEC or subject to Regulation 14A or 14C or to the liabilities of Section 18 of the Exchange Act, or incorporated by reference into any filing under the Securities Act or the Exchange Act, except to the extent that we specifically request that such information be treated as soliciting material or specifically incorporate it by reference into such a filing. The graph is required by applicable rules of the SEC and is not intended to forecast, predict or be indicative of the possible future performance of our common stock.

The following graph compares the five-year total return to holders of our common stock relative to the cumulative total returns of the Nasdaq Global Market Index and the Russell 2000 Index. The graph assumes that $100 was invested in our common stock and in each of these indices at the close of market on December 31, 2018 (the last trading day before the beginning of our fifth preceding fiscal year). We chose to include the Russell 2000 Index because it includes issuers with similar market capitalizations and due to the lack of a comparable industry or line-of-business index or peer group,

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as we are the only actively traded public company whose only line of business is to sell natural gas for use as a vehicle fuel and the associated equipment and services necessary to use natural gas as a vehicle fuel.

Item 6.   [Reserved].

​

Item 7.   Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The following Management’s Discussion and Analysis of Financial Condition and Results of Operations (this discussion, as well as discussions under the same heading in our other periodic reports, are referred to as the “MD&A”) should be read together with our audited consolidated financial statements and the related notes included in this report, and all cross references to notes included in this MD&A refer to the identified note in such consolidated financial statements. This section of the Form 10-K generally discusses 2023 and 2022 items and year-to-year comparisons of 2023 to 2022. Discussions of 2021 items and year-to-year comparisons of 2022 and 2021 that are not included in this Form 10-K can be found in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Part II, Item 7 of our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 28, 2023.

Cautionary Note Regarding Forward-Looking Statements

This MD&A contains forward-looking statements. See the discussion about these statements under “Cautionary Note Regarding Forward-Looking Statements” at the beginning of this report.

Overview

We are North America’s leading provider of the cleanest fuel for the transportation market, based on the number of stations operated and the amount of gasoline gallon equivalents (“GGEs”) of renewable natural gas (“RNG”) and conventional natural gas sold. We calculate one GGE to equal 125,000 British Thermal Units (“BTUs”) and, as such, one million BTUs (“MMBTU”) equals eight GGEs. Through our sales of RNG, which is derived from biogenic methane produced by the breakdown of organic waste, we help thousands of vehicles, from airport shuttles to city buses to waste and heavy-duty trucks, reduce their amount of climate-harming greenhouse gases (“GHG”) from 60% to over 400% based on determinations by the California Air Resources Board (“CARB”), depending on the source of the RNG, while also

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reducing criteria pollutants such as Nitrogen Oxides, or NOx. RNG is either delivered as compressed natural gas (“CNG”) or liquefied natural gas (“LNG”).

As a clean energy solutions provider, we supply RNG (sourced from third party sources and from our anaerobic digester gas (“ADG”) RNG joint venture project with TotalEnergies S.E. (the “DR JV”) (see Note 4)) and conventional natural gas (sourced from third party suppliers), in the form of CNG and LNG, for medium and heavy-duty vehicles; design and build, as well as operate and maintain (“O&M”), public and private vehicle fueling stations in the United States (“U.S.”) and Canada; develop and own dairy anaerobic digester gas (“ADG”) RNG production facilities; sell and service compressors and other equipment used in RNG production and at fueling stations; transport and sell RNG and conventional natural gas via “virtual” natural gas pipelines and interconnects; sell U.S. federal, state and local government credits (collectively, “Environmental Credits”) we generate by selling RNG as a vehicle fuel, including Renewable Identification Numbers (“RIN Credits” or “RINs”) under the federal Renewable Fuel Standard Phase 2 and credits under the California, Oregon, and Washington Low Carbon Fuel Standards (collectively, “LCFS Credits”); and obtain federal, state and local tax credits, grants and incentives.

At present, we see the best use of RNG as a replacement for fossil-based fuel in the transportation sector. We believe the most attractive market for RNG is U.S. heavy-duty Class 8 trucking and, based on information from the American Trucking Association and our own internal estimates, we believe there are approximately 4.1 million Class 8 heavy-duty trucks operating in the U.S. that use over 40 billion gallons of fuel per year. As of December 31, 2023, we deliver RNG to the transportation market through 579 fueling stations we own, operate or supply in 43 states and the District of Columbia in the U.S., including over 200 stations in California. We also own, operate, or supply 24 fueling stations in Canada as of December 31, 2023.

Critically, to generate the valuable Environmental Credits, RNG must be placed in vehicle fuel tanks. We believe our stations and customer relationships allow us to deliver substantially more RNG to vehicle operators than any other participant in the market – we calculate that we have access to more fueling stations and vehicle fleets than all our competitors combined. As of December 31, 2023, we served over 1,000 fleet customers operating over 50,000 vehicles on our fuels.

Longer term, we plan to expand availability of hydrogen fuel for vehicle fleets. As operators deploy more hydrogen powered vehicles, we can modify our fueling stations to reform our RNG and deliver clean hydrogen to customers. We also believe our RNG can be used to generate clean electricity to power electric vehicles, and we have the capability to add electric vehicle charging at our station sites, although the cost of adding electric vehicle charging capacity may be significant.

Impact of COVID-19, Inflation, Labor Shortage, Material Availability and Interest Rate

The COVID-19 pandemic had an adverse effect on the volume of our sales, which we saw bottom in the second quarter of 2020. The subsequent surge in cases driven by the omicron variant negatively affected the demand recovery for our vehicle fuels in the first quarter of 2022. Since that time, we have seen improvement in volumes in all customer markets, and the residual effects of the COVID-19 pandemic have not been a significant headwind to our business operations. For more information, see “Risk Factors” in Part I, Item 1A of this report.

In recent periods, we have experienced increases in commodity and supply chain costs due to inflationary pressures. Additionally, effects stemming from the COVID-19 pandemic have caused disruptions in labor supply and in supply chains, leading to shortages of certain materials and equipment and higher labor costs that have continued to linger to some extent. The future duration and extent of these pressures and effects are difficult to predict. Although we have partially offset these increased costs through price increases for our products and services, our efforts to manage the current inflationary pressure and to recover inflation-based cost increases from our customers may be hampered by the structure of our contracts as well as the competitive and economic conditions of the markets in which we serve. For more information, see “Risk Factors” in Part I, Item 1A of this report.

As of December 31, 2023, the majority of our debt outstanding represents a long-term loan bearing a fixed rate of interest. Changes in market interest rates do not affect the interest expense incurred from this outstanding long-term debt

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instrument. However, changes in market interest rates may affect the interest rate and corresponding interest expense on any new issuance of short-term and long-term debt securities. See “Quantitative and Qualitative Disclosures about Market Risk” in Part II, Item 7A of this report for more information.

We believe we have sufficient liquidity to support business operations through this volatile period, including total cash and cash equivalents and short-term investments of $263.1 million, excluding current portion of restricted cash, as of December 31, 2023 and $1.8 million of current debt. We have collected nearly all receivables relating to alternative fuel excise tax credits (“AFTC”) generated from 2022 fuel sales in 2023. In addition, as a result of the Inflation Reduction Act of 2022 being enacted on August 16, 2022 (the “IRA”), AFTC was reinstated and extended for an additional three years, beginning retroactively to January 1, 2022. For the year ended December 31, 2023, we recognized $20.9 million in AFTC revenue.

Performance Overview

This performance overview discusses matters on which our management focuses in evaluating our financial condition and our operating results.

Sources of Revenue

The following table presents our sources of revenue:

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Key Operating Data

In evaluating our operating performance, we focus primarily on: (1) the amount of total fuel volume we sell to our customers with particular focus on RNG volume as a subset of total fuel volume, (2) O&M services volume dispensed at facilities we do not own but where we provide O&M services on a per-gallon or fixed fee basis, (3) our station construction cost of sales, and (4) net income (loss) attributable to us. The following tables present our key operating data for the years ended December 31, 2021, 2022 and 2023. Certain gallons are included in both fuel and service volumes when the Company sells fuel (product revenue) to a customer and provides maintenance services (service revenue) to the same customer.

​

​

2022 – 2023 Key Developments

TotalEnergies Joint Venture. In the first quarter of 2023, the DR JV began producing RNG and made its first injection into the natural gas pipeline; since then, the production of RNG at the DR JV has continued to ramp up. On June 27, 2023, the DR JV issued a capital call for $11.0 million of additional funding, requiring TotalEnergies and the Company each to contribute $5.5 million. On June 28, 2023, the Company contributed $5.5 million and advanced $5.5 million to the DR JV. The $5.5 million advance was subsequently refunded to the Company by the DR JV in December 2023. Funds from the capital call were primarily used to fund required loan reserves and to paydown outstanding liabilities of the DR JV.

bp Joint Venture. The RNG production facility at Drumgoon Dairy was placed into service in the fourth quarter of 2023. This RNG project is designed to supply approximately 1.7 million GGEs of RNG annually when at full capacity. As of December 31, 2023, there were four RNG projects under construction in the bp Joint Venture (“bpJV”) that were nearing substantial completion. All RNG produced from projects in the bpJV will be available to us for sale as vehicle fuel pursuant to our existing marketing agreement with bp.

In connection with the capital call issued by the bpJV in December 2021, on June 30, 2022, we paid the remaining outstanding contribution balance of $51.6 million to the bpJV and satisfied our capital contribution commitment under this capital call. On March 30, 2022, the bpJV issued a capital call in the amount of $76.2 million, and, on September 30, 2022, we and bp each contributed $38.1 million to the bpJV in connection with this capital call. On December 20, 2023, the bpJV issued a capital call in the amount of $135.9 million, and, on December 28, 2023, we and bp each contributed

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$67.95 million to the bpJV. Proceeds from these capital calls are used to develop ADG RNG projects and to fund bpJV’s working capital needs.

Tourmaline Joint Development. On April 18, 2023, we and Tourmaline Oil Corp. (“Tourmaline”) announced a CAD $70 million Joint Development Agreement to build and operate a network of CNG stations along key highway corridors across Western Canada. Under a 50-50 shared investment, we and Tourmaline expect to construct and commission up to 20 CNG fueling stations over the next five years, allowing heavy-duty trucks and other commercial transportation fleets that operate in the area to transition to the use of CNG, a lower carbon alternative to gasoline and diesel. On June 16, 2023, we entered into a construction, ownership and operation agreement with Tourmaline to jointly own and operate a CNG fueling station located in Edmonton, Alberta. Additional stations are expected in the municipalities of Calgary, Edson, and Grande Prairie in Alberta and Kamloops in British Columbia.

Winter 2022–2023 California Natural Gas Prices. From December 2022 to February 2023, the wholesale prices of natural gas in California spiked to historic levels. The January 2023 monthly index for Southern California settled at $54.31, and Henry Hub settled at $4.71, or 11.5 times higher than the industry benchmark index. December 2022 and February 2023 bookended the historic spike with the Southern California monthly index settled at $15.11 and $13.21, respectively, while Henry Hub settled at $6.71 and $3.11, respectively. These settlement prices reflect the monthly index established during the week leading up to the actual delivery month, also known as the bidweek. Drivers of the price increase were a combination of record below normal temperatures, production freeze-offs, pipeline maintenance, and an accelerated depletion of stored natural gas reserves. As a result, we experienced significantly higher gas supply costs, which affected our fueling stations in California in January 2023 and into February 2023. Although we have partially offset the increased costs through price increases from our customers, not all increased costs were recovered due to the competitive nature and market dynamics of the markets in which we serve. We estimate that the natural gas price spike in California from December 2022 to February 2023 resulted in a reduction in gross profit of approximately $10.0 million for the three months ended March 31, 2023. Since then, we have seen wholesale prices of natural gas in California largely revert to normal levels.

South Fork Dairy Farm Incident. On April 10, 2023, an accident resulted in a fire at the South Fork Dairy farm in Dimmitt, Texas, the location of one of our 100% owned ADG RNG projects under development. The fire killed approximately 18,000 dairy cows and injured one person. Our partner, South Fork Dairy, plans to rebuild the dairy farm and to replenish the dairy cattle. At the time of the incident, we had not commenced onsite construction activities. Rebuilding efforts were initiated in late 2023. Since then, we have begun to prepare for the construction of the ADG RNG project, and construction activities may start as early as the first quarter of 2024. Due to the effects of this incident, we anticipate a delay to the initial planned completion date of this ADG RNG project.

EPA Renewable Fuels Standard Update. On June 21, 2023, the Environmental Protection Agency (“EPA”) announced a final rule to establish the renewable volume obligation (“RVO”) for 2023 through 2025, increasing the RVO demand targets by an average of approximately 30% per year over the next three years. We believe this action by the EPA is constructive to the development and use of RNG as a low-carbon fuel for the transportation sector.

Stonepeak Credit Agreement. On December 12, 2023, we entered into a six-year $300 million senior secured first lien term loan with Stonepeak (the “Stonepeak Credit Agreement”), a leading alternative investment firm specializing in infrastructure and real assets. The Stonepeak Credit Agreement also provides for a two-year delayed draw term loan commitment of an additional $100 million. In addition to repaying existing loans, the Stonepeak Credit Agreement will provide us with capital for new RNG production facilities, as well as the expansion of our fueling infrastructure targeting the heavy-duty truck market. In connection with this transaction, we issued warrants to Stonepeak (the “Stonepeak Warrant”) providing the right to purchase 10 million shares of common stock at an exercise price of $5.50 per share and 10 million shares of common stock at an exercise price of $6.50 per share. The Stonepeak Warrant expires on June 15, 2032 and are exercisable at any time after December 12, 2025. See Note 12 for more information about our outstanding debt and Note 13 for additional information about the Stonepeak Warrant.

Riverstone Credit Agreement. On December 22, 2022, we entered into a four-year $150.0 million sustainability-linked senior secured first lien term loan (the “Riverstone Credit Agreement”) with certain affiliates of, or funds managed by, Riverstone Credit Partners L.P., a dedicated credit investment platform managed by Riverstone Holdings LLC

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(“Riverstone”) that focuses on energy, power, decarbonization, and infrastructure. This financing provided us with additional capital to execute our RNG growth strategy, which includes the development of negative carbon intensity RNG projects and construction of new RNG fueling stations for transportation sector customers. Proceeds from the term loan will be used, in part, to accelerate our expansion and development of ADG RNG production projects. On December 12, 2023, in connection with the Stonepeak Credit Agreement, we repaid in full the $150.0 million sustainability-linked senior secured first lien term loan, including related accrued and unpaid interest. Upon such payment, the Riverstone Credit Agreement, dated December 22, 2022, was terminated. See Note 12 for more information about our outstanding debt.

NG Advantage Debt Refinancing and Extinguishment. On January 31, 2022, NG Advantage LLC (“NG Advantage”) entered into a second amendment to the Amended and Restated Loan and Security Agreement with Berkshire Bank (the “Berkshire ALA”) pursuant to which Berkshire Bank agreed to extend new term loans in an aggregate principal amount of $14.0 million (collectively, the “Berkshire Term Loan 2”) to NG Advantage. The Berkshire Term Loan 2 bore interest at an annual interest rate of 5% and had a maturity date of January 31, 2027. Payments for interest and principal were due monthly beginning March 1, 2022, with a final payment of remaining principal and interest due on the maturity date. Borrowings under the Berkshire Term Loan 2 were collateralized by NG Advantage’s trailers and station assets, and prepayment of the outstanding principal was permitted and subject to prepayment premiums. NG Advantage used the proceeds from the Berkshire Term Loan 2 to extinguish $11.1 million of existing financing obligations, consisting of $10.4 million in cash payoffs and an application of $0.8 million in deposits held with the former lenders. As a result of the extinguishment, we recognized a $2.3 million loss on extinguishment of debt, which is included in “interest expense” in the accompanying consolidated statements of operations for the year ended December 31, 2022. In connection with the second amendment to the Berkshire ALA, Berkshire Bank released $7.0 million to the Company related to the Company’s limited guaranty under the Berkshire ALA.

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On December 22, 2022, pursuant to the Riverstone Credit Agreement, NG Advantage fully repaid all outstanding principal balances and related accrued and unpaid interest under the Berkshire ALA and the Berkshire Term Loan 2. In connection with the extinguishments of debt under the Berkshire ALA and the second amendment to the Berkshire ALA, NG Advantage recognized a $1.1 million loss on debt extinguishment, which is included in “interest expense” in the accompanying consolidated statements of operations for the year ended December 31, 2022.

Plains Credit Facility. Pursuant to the Riverstone Credit Agreement, on December 22, 2022, the Plains LSA was terminated. Concurrently, the irrevocable standby letter of credit issued to Berkshire Bank in connection with the second amendment to the Berkshire ALA was cancelled. As a result, we deposited $2.0 million, in the form of a certificate of deposit, at PlainsCapital Bank (“Plains”) that serves as a security collateral for the standby letter of credit issued to Chevron Products Company, a division of Chevron U.S.A. Inc. The $2.0 million is classified as short-term restricted cash and a current asset and is included in “Cash, cash equivalents and current portion of restricted cash” in the accompanying consolidated balance sheets as of December 31, 2022 and 2023.

AFTC. The IRA reinstated and extended the AFTC incentive for three years through December 31, 2024, beginning retroactively to January 1, 2022. Under the extension period, AFTC incentive remains at $0.50 per GGE of CNG and $0.50 per diesel gallon of LNG that we sell as vehicle fuel through 2024.

Fueling Station Equipment Removal. On July 7, 2022, we entered into an amendment to our Liquefied Natural Gas Fueling Station and LNG Master Sales Agreement with Pilot Travel Centers LLC (“Pilot”), dated August 2, 2010, to decommission and remove station equipment of select fueling stations located on Pilot’s premises as agreed to in a phased removal schedule. The removal of the fueling station equipment and site improvements commenced in the third quarter of 2022 and was completed by the end of the third quarter of 2023.

Debt Level and Debt Compliance

As of December 31, 2023, we had total indebtedness, excluding finance lease obligations, of $300.3 million in principal amount, of which $0.0 million is expected to become due in 2024. Certain of the agreements governing our outstanding debt, which are discussed in Note 12, have certain financial and non-financial covenants with which we must comply. As of December 31, 2023, we were in compliance with all of these covenants.

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Key Trends

Market for RNG and conventional natural gas as a Vehicle Fuel

According to CARB, RNG and conventional natural gas are cleaner than gasoline and diesel fuel based on the GHG emissions produced by vehicles operated by these fuels. Additionally, RNG and conventional natural gas are generally less expensive for vehicle operators than gasoline and diesel on an energy equivalent basis. According to the U.S. Energy Information Administration, demand for renewable and conventional natural gas fuels in the U.S. has increased in recent years and is expected to continue to increase. We expect our sales of RNG and conventional natural gas to grow as more companies look to operate in an increasingly sustainable way. In addition to pressure from politicians, regulators and non-governmental organizations, the investment community has dramatically increased demands on companies to diminish their contributions to climate change. We believe that RNG is the best tool available today to reduce climate-harming GHG and meet sustainability objectives.

The market for our vehicle fuels, however, is a relatively new and developing market. As a result, it is difficult to accurately predict demand for our vehicle fuels, in general and in any specific geographic and customer markets, and consequently our timing and level of investment in particular markets may not be consistent with any growth in demand in these markets. Further, the new and developing nature of the market for our vehicle fuels has led to slow, volatile or unpredictable growth in many sectors. For example, to date, adoption and deployment of natural gas vehicles, both in general and in certain of our key customer markets, including heavy-duty trucking, have been slower than we anticipated.

We believe challenging market conditions are caused by a number of factors, including the following: