The Company recognized $4.2 million of stock-based compensation benefit and $4.3 million of stock-based compensation expense for the three months ended June 30, 2024, and 2023, respectively. The Company recognized $0.1 million and $7.1 million of stock-based compensation expense for the six months ended June 30, 2024, and 2023, respectively. As of June 30, 2024, the Company had $34.7 million of unrecognized share-based compensation expense related to unvested restricted units, respectively, which the Company expects to recognize over a weighted-average period of approximately 2 years.

Prior to the Merger, Legacy Altus maintained the APAM Holdings LLC Restricted Units Plan, adopted in 2015 (the “APAM Plan”) and APAM Holdings LLC adopted the 2021 Profits Interest Incentive Plan (the “Holdings Plan”, and together with the APAM Plan, the “Legacy Incentive Plans”), which provided for the grant of restricted units that were intended to qualify as profits interests to employees, officers, directors and consultants. In connection with the Merger, vested restricted units previously granted under the Legacy Incentive Plans were exchanged for shares of Class A Common Stock, and unvested Altus Restricted Shares under each of the Legacy Incentive Plans were exchanged for restricted Class A Common Stock with the same vesting conditions. As of June 30, 2024, and December 31, 2023, zero and 210,710 shares of Class A Common Stock were restricted under the Holdings Plan, respectively. No further awards will be made under the Legacy Incentive Plans.

The fair value of the granted units was determined using the Black-Scholes Option Pricing model and relied on assumptions and inputs provided by the Company. All option models utilize the same assumptions with regard to (i) current valuation, (ii) volatility, (iii) risk-free interest rate, and (iv) time to maturity. The models, however, use different assumptions with regard to the strike price which vary by award.

On July 12, 2021, the Company entered into the Management Equity Incentive Letter with each of Mr. Felton and Mr. Norell pursuant to which, on February 5, 2022, the compensation committee granted to Mr. Felton and Mr. Norell, together with other senior executives, including Mr. Savino, Chief Construction Officer, and Mr. Weber, Chief Financial Officer, restricted stock units (“RSUs”) under the Omnibus Incentive Plan (the "Incentive Plan") that are subject to time-based and, for the named executive officers and certain other executives, eighty percent (80%) of such RSUs also further subject to performance-based vesting, with respect to an aggregate five percent (5%) of the Company’s Class A common stock on a fully diluted basis, excluding the then-outstanding shares of the Company’s Class B common stock or any shares of the Company’s Class A common stock into which such shares of the Company’s Class B common stock are or may be convertible. Subject to continued employment on each applicable vesting date, the time-based RSUs generally vest 33 1/3% on each of the third, fourth and fifth anniversaries of the Closing, and the performance-based RSUs vest with respect to 33 1/3% of the award upon the achievement of the above time-based requirement and the achievement of a hurdle representing a 25% annual compound annual growth rate measured based on an initial value of $10.00 per share (i.e., on each of the third anniversary, the fourth anniversary, and the fifth anniversary of the date of grant, the stock price performance hurdle shall be $19.53, $24.41, $30.51, respectively), which vesting is eligible until the fifth anniversary of grant date.

On March 28, 2024, the vesting conditions of such performance-based RSUs were modified by the compensation committee to set the hurdles at $14.00, $18.00, and $22.00, respectively. This modification impacted five grantees and resulted in $3.1 million of incremental expense. As of June 30, 2024, the unrecognized expense related to the modification was $1.3 million, which the Company expects to recognize over a weighted average period of 2 years.

Additionally, under the Incentive Plan the Company granted performance stock units ("PSUs") that are subject to market and service vesting conditions, each of which represents the right to receive one share of the Company's Class A Common Stock and which vest in one installment on the third anniversary of the grant date based upon the Company's total stockholder return when compared to the Invesco Solar ETF (TAN), subject to certain adjustments, and the Russell 2000 index, assigning a weight of 50% to each. The number of PSUs vested, and thus shares of Class A Common Stock issued, could range from 0 to 150% of such PSUs.

During the three and six months ended June 30, 2024, the Company granted under the Incentive Plan an additional 50,000 and 3,023,127 RSUs, respectively, that are subject to time-based vesting as described above, with a weighted average grant date fair value per share of $4.50 and $4.88, respectively. During the six months ended June 30, 2024, the Company also granted 546,024 PSUs that are subject to market-based vesting as described above, with a grant date fair value per share of $5.22. Further, the Company granted 751,773 of incentive performance stock units ("GW Plan PSUs") that cliff vest on December 31, 2026, if the Company adds 1.1 gigawatt of installed solar capacity starting January 1, 2024 and subject to continued employment on the vesting date. The number of GW Plan PSUs vested, and thus shares of Class A Common Stock issued, will be calculated based on the average stock price of the Company's Class A Common Stock during the twenty trading days prior to and including (if applicable) the vesting date (the "AMPS Price") as follows:

As of both June 30, 2024, and December 31, 2023, there were 30,992,545 shares of the Company's Class A common stock authorized for issuance under the Incentive Plan. The number of shares authorized for issuance under the Incentive Plan will increase on January 1 of each year from 2024 to 2031 by the lesser of (i) 5% of the number of shares outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the Company's board of directors. The number of shares authorized for issuance under the Incentive Plan increased by 5% of outstanding shares as

For the three months ended June 30, 2024, and 2023, the Company granted 50,000 and 10,000 RSUs, respectively, and recognized $4.2 million of stock-based compensation benefit and $4.3 million of stock-based compensation expense, respectively, in relation to the Incentive Plan. For the six months ended June 30, 2024 and 2023, the Company granted 4,320,924 and 3,021,148 RSUs, respectively, and recognized $0.1 million and $7.1 million, respectively, of stock-based compensation expense in relation to the Incentive Plan. For the three months ended June 30, 2024, and 2023, 4,485,171 and 5,354 RSUs were forfeited, respectively. For the six months ended June 30, 2024 and 2023, 4,518,592 and 11,054 RSUs were forfeited, respectively.

Included in forfeited RSUs are the 4,283,452 unvested RSUs and PSUs granted under the Incentive Plan to Mr. Norell, which were forfeited in connection with the CEO transition described in Note 12, "Related Party Transactions." This forfeiture resulted in the reversal of $8.7 million of previously recognized stock-based compensation expense during the three months ended June 30, 2024.

On December 9, 2021, we adopted the 2021 Employee Stock Purchase Plan ("ESPP"), which provides a means by which eligible employees may be given an opportunity to purchase shares of the Company’s Class A common stock. As of both June 30, 2024, and December 31, 2023, there were 4,662,020 shares of the Company's Class A common stock authorized for issuance under the ESPP. The number of shares authorized for issuance under the ESPP will increase on January 1 of each year from 2024 to 2031 by the lesser of (i) 1% of the number of shares outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the Company's board of directors. No shares of the Company’s Class A common stock were issued and no stock-based compensation expense was recognized in relation to the ESPP for the six months ended June 30, 2024, and 2023. The number of shares authorized for issuance under the ESPP increased by 1% of outstanding shares as described in the foregoing on January 1, 2022 and January 1, 2023. The number of shares authorized for issuance under the ESPP did not increase on January 1, 2024.