Clean Energy Fuels Corp. Fair Value Disclosure

Note 7 —Fair Value Measurements

The Company follows the authoritative guidance for fair value measurements with respect to assets and liabilities that are measured at fair value on a recurring basis and non-recurring basis. Under the standard, fair value is defined as the exit price, or the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants, as of the measurement date. The standard also establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use in valuing the asset or liability developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the factors market participants would use in valuing the asset or liability developed based upon the best information available in the circumstances. The hierarchy consists of the following three levels: Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities; Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs (other than quoted prices) that are observable for the asset or liability, either directly or indirectly; Level 3 inputs are unobservable inputs for the asset or liability. Categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The Company’s U.S. government issued debt securities are classified within Level 1 because they are valued using the most recent quoted prices for identical assets in active markets. Certificate of deposits are classified within Level 2 because they are valued using the most recent quoted prices for identical assets in markets that are not active and quoted prices for similar assets in active markets.

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The Company used the income approach to value its outstanding commodity swap contracts and embedded derivatives in its fueling agreements under the Zero Now truck financing program (see Note 6). Under the income approach, the Company used a discounted cash flow (“DCF”) model in which cash flows anticipated over the term of the contracts are discounted to their present value using an expected discount rate. The discount rate used for cash flows reflects the specific risks in spot and forward rates and credit valuation adjustments. This valuation approach is considered a Level 3 fair value

measurement. The significant unobservable inputs used in the fair value measurement of the Company’s derivative instruments are Ultra-Low Sulfur Diesel (“ULSD”) forward prices and differentials from ULSD to Petroleum Administration for Defense District (“PADD”) regions. Significant increases (decreases) in any of those inputs in isolation would result in a significantly lower or higher fair value measurement. Generally, a change in the ULSD forward prices is accompanied by a directionally opposite but less extreme change in the ULSD-PADD differential.

The Company estimated the fair value of embedded derivatives in its fueling agreements under the Zero Now truck financing program based on the following inputs as of December 31, 2024 and 2025:

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Convertible Promissory Note

In connection with the Company’s loan commitment (See Note 14) to Rimere, LLC (“Rimere”), a former equity method investee, the Company acquired convertible promissory notes with aggregate principal balances equaling the total amount of drawdowns on the loan commitments. In addition, in May 2024, the Company invested in a convertible promissory note (the “Convertible Promissory Note Agreement”) with a principal balance of $2.0 million issued by Bridge to Renewables, Inc. (“BTR”). These convertible promissory notes are classified as available-for-sale and are carried at fair value, which is measured using the income approach. Under the income approach, the Company used a DCF model in which cash flows anticipated over the term of the notes are discounted to their present value using an expected discount rate. The discount rate used reflected the interest rates offered on loans of similar term and to borrowers of similar credit quality, which are Level 3 inputs. As such, this valuation approach is considered a Level 3 fair value measurement.

The following table provides quantitative information about the significant inputs used to estimate the fair value of the convertible promissory notes from Rimere as of December 31, 2024 and 2025:

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The following table provides quantitative information about the significant inputs used to estimate the fair value of the convertible promissory note from BTR as of December 31, 2024. BTR was sold in August 2025 (refer to Note 3), and therefore, there is no balance remaining as of December 31, 2025:

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The above significant unobservable inputs are subject to change based on changes in economic and market conditions. The use of significant unobservable inputs creates uncertainty in the measurement of fair value as of the reporting date. Significant increase or decrease in any of those inputs in isolation would result in a significantly lower or higher fair value measurement. Generally, a change in market interest rates is accompanied by a directionally opposite change in the estimated fair value of fixed-rate debt securities. The Company records changes in the fair value of available-for-sale debt

securities in “Unrealized gain (loss) on available-for-sale securities” within other comprehensive income (loss) in the accompanying consolidated statements of comprehensive loss. In addition, because the Company has reduced its equity method investment in the investee to zero but has other investment in the investee such as the convertible promissory note, the remeasurement to fair value is applied to the convertible promissory note’s adjusted carrying balance after the recognition of equity method losses, which is calculated based on the Company’s percentage ownership interest in such other investment.

Investment Tax Credit

The Company’s ITC is recorded at fair value equal to the price that the Company expects to receive upon sale of the tax credit in an orderly transaction to a third party. The Company estimates the fair value by applying a discount for monetization to the gross value of the tax credit, reflecting the risk profile of the transferable tax credit market and the Company’s assessment of market participant assumptions.

There were no transfers of assets or liabilities between Level 1, Level 2, and Level 3 of the fair value hierarchy as of December 31, 2024 or 2025.

The following tables provide information by level for assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2024 and 2025 (in thousands):

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The following table provides a reconciliation of the beginning and ending balances of items measured at fair value on a recurring basis as shown in the tables above that used significant unobservable inputs (Level 3), as well as the change in unrealized gains or losses for the periods included in earnings or other comprehensive income (loss) (in thousands):

(1) Represents the Company’s proportionate share of Rimere’s losses. These losses are recorded as adjustments to the carrying value of the convertible promissory notes because the Company’s equity investment in Rimere had been reduced to zero.

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Other Financial Assets and Liabilities

The carrying amounts of the Company’s cash, cash equivalents, receivables and payables approximate fair value due to the short-term nature of those instruments.

Debt instruments as of December 31, 2024 consisted of the following (in thousands):

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Debt instruments as of December 31, 2025 consisted of the following (in thousands):

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The fair values of these debt instruments were estimated using a DCF analysis based on imputed interest rates, which are Level 3 inputs. See Note 11 for more information about the Company’s debt instruments.