H.R. 603 — Reinforcing the Grid Against Extreme Weather Act of 2025

This section establishes a new section 224 of the Federal Power Act directing the Federal Energy Regulatory Commission (FERC) to improve interregional electricity transfer capability. Not later than 24 months after enactment, FERC must issue regulations establishing processes for (1) calculating existing transfer capability between each transmission planning region (i.e., geographic areas defined under FERC Order No. 1000) and adjacent regions using uniform, Commission-approved methods; (2) determining minimum transfer capabilities to ensure reliability during weather, physical, or cyber events and to optimize transmission benefits (e.g., reduced congestion, access to lower-cost or zero-emission generation); (3) identifying, selecting, and allocating costs for interregional transmission projects to achieve those minima; and (4) protecting cyberattack-related information. Not later than 3 years after enactment, and every 5 years thereafter, transmission planning entities for pairs of adjacent regions must file FERC-approved plans evaluating and selecting such projects; FERC must approve or deny plans based on the reliability and benefits criteria. Not later than 48 months after issuing the regulations, and annually thereafter, FERC must publish a Federal Register report on implementation results. The section defines key terms, including transmission benefit (encompassing reliability, resilience, economic, environmental, and public policy advantages) and greenhouse gas (listing 11 specific gases and classes).