On December 4, 2024, the US Treasury and IRS issued final regulations, TD 10015, providing guidance on energy property definitions and rules for the energy credit under Section 48 of the Internal Revenue Code. The regulations clarify the eligibility criteria for the investment tax credit (ITC) and implement amendments by the Inflation Reduction Act of 2022. Updates include modifications to qualified biogas property, energy storage technology rules, and energy property aggregation rules. The regulations enable taxpayers to understand when multiple units of energy property constitute a single project, address recapture rules, and include qualified interconnection costs. The ITC is available for properties under construction by December 31, 2024. The Final Regulations aim to offer clarity and flexibility for taxpayers in complying with the ITC regulations, providing guidance on qualified energy property and ensuring taxpayers meet prevailing wage and apprenticeship requirements.