6. Fair Value Measurements

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The Company records the fair value of assets and liabilities in accordance with ASC 820, Fair Value Measurement (“ASC 820”). ASC 820 defines fair value as the price received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. The fair value should be calculated based on assumptions that market participants would use in pricing the asset or liability, not on assumptions specific to the entity.

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In addition to defining fair value, ASC 820 expands the disclosure requirements around fair value and establishes a fair value hierarchy for valuation inputs. The hierarchy prioritizes the inputs into three levels based on the extent to which inputs used in measuring fair value are observable in the market. Each fair value measurement is reported in one of the three levels, which is determined by the lowest level input that is significant to the fair value measurement in its entirety.

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These levels are:

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Financial instruments not recorded at fair value on a recurring basis include equity method investments that have not been remeasured or impaired in the current period, such as our investments in AccionaPlug S.L. and Clean H2 Infra Fund.

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The following table summarizes the carrying amount and estimated fair value of the Company’s financial instruments as of March 31, 2026 and December 31, 2025 (in thousands):

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The liabilities measured at fair value on a recurring basis that have unobservable inputs and are therefore categorized as Level 3 are related to the $7.75 Warrants, 6.75% Convertible Senior Notes (each, as defined below) and contingent consideration, all of which are described below.

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Assets and Liabilities Measured at Fair Value on a Recurring Basis

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$7.75 Warrants

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The fair value of the $7.75 Warrants as of March 31, 2026 and December 31, 2025 was comprised of a single financial liability under ASC 825 with changes in fair value recorded in gain/loss from changes in fair value of warrant liabilities recorded in the unaudited interim condensed consolidated statements of operations.

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The Company estimated and recorded the fair value of the $7.75 Warrants as of March 31, 2026 and December 31, 2025 based on a Black-Scholes Option Pricing Model. The valuations utilized significant Level 3 unobservable inputs, including volatility. Other significant assumptions include risk-free rate, exercise price, the Company’s common stock price and maturity date. Significant judgment is required in selecting the significant inputs and assumptions. Actual assumptions may differ from our current estimates and such differences could materially impact the fair value of the $7.75 Warrants.

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Refer to Note 7, “Warrant Liabilities,” for the significant assumptions utilized in the fair value of the $7.75 Warrants as of March 31, 2026 and December 31, 2025, respectively, as well as the change in the carrying amount of the $7.75 Warrants during the three months ended March 31, 2026.

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6.75% Convertible Senior Notes

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The fair value of the 6.75% Convertible Senior Notes as of March 31, 2026 and December 31, 2025 was comprised of a single financial liability in which the Company elected the fair value option under ASC 825, Financial Instruments (“ASC 825”), with changes in fair value recorded in gain/loss from change in fair value of convertible debt instruments in the unaudited interim condensed consolidated statements of operations. The Company elected the fair value option due to its multiple conversions features required to be presented at fair value. The Company has also elected to present interest expense separately from the change in fair value of convertible debt instruments measured at fair value through earnings. Total changes in the fair value of the liability that resulted from a change in the instrument-specific credit risk are separately recorded in other comprehensive income. There was no change in the instrument-specific credit risk during the three months ended March 31, 2026.

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As of March 31, 2026, the Company estimated and recorded the fair value of the 6.75% Convertible Notes based on a Lattice Model. The valuation utilized significant Level 3 unobservable inputs, including volatility and calibrated yield. Other significant assumptions include risk-free rate, conversion price, coupon interest rate, the Company’s common stock price, issuance date and maturity date. Significant judgment is required in selecting the significant inputs and assumptions. Actual assumptions may differ from our current estimates and such differences could materially impact the fair value of the 6.75% Convertible Notes. As of December 31, 2025, the Company estimated and recorded the fair value of the 6.75% Convertible Notes utilizing Level 1 inputs as it was based on recent trading activity. As such, the 6.75% Convertible Senior Notes were transferred from Level 1 to Level 3 during the three months ended March 31, 2026.

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Refer to Note 8, “Convertible Senior Notes,” for the change in the carrying amount of the 6.75% Convertible Senior Notes during the three months ended March 31, 2026.

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Contingent consideration

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The fair value of contingent consideration as of March 31, 2026 is related to the Joule Processing LLC (“Joule”) acquisition in 2022 and the fair value of contingent consideration as of December 31, 2025 is related to the Joule acquisition in 2022 and the Frames Holding B.V. (“Frames”) acquisition in 2021.

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In the unaudited interim condensed consolidated balance sheets, contingent consideration was recorded in the contingent consideration, loss accrual for service contracts, and other current liabilities and contingent consideration, loss accrual for service contracts, and other liabilities financial statement line items and was comprised of the following unobservable inputs as of March 31, 2026:

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In the unaudited interim condensed consolidated balance sheets, contingent consideration was recorded in the contingent consideration, loss accrual for service contracts, and other current liabilities and contingent consideration, loss accrual for service contracts, and other liabilities financial statement line items and was comprised of the following unobservable inputs as of December 31, 2025:

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The change in the carrying amount of contingent consideration during the three months ended March 31, 2026 was as follows (in thousands):

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