## Facts

- EPA promulgated the 2015 Clean Power Plan (CPP) under Clean Air Act (CAA) § 111(d) to regulate CO₂ emissions from existing coal- and gas-fired power plants.
- The CPP set state-specific emissions performance rates derived from three “building blocks”: (1) heat-rate improvements at coal plants, (2) shifting generation from coal to natural gas, and (3) shifting generation from fossil fuels to renewables, including through emissions trading.
- The CPP was stayed by the Supreme Court in 2016 and never took effect.
- EPA later repealed the CPP and adopted the Affordable Clean Energy (ACE) Rule, limiting the “best system of emission reduction” (BSER) for existing coal units to within-facility heat-rate improvements.
- In 2021, the D.C. Circuit vacated both the CPP repeal and the ACE Rule and remanded, concluding EPA had misread § 111(d).
- A group of states led by West Virginia and coal-industry petitioners sought Supreme Court review; EPA and other respondents defended EPA’s asserted authority.
- The Supreme Court reached the merits, finding the dispute not moot and petitioners had standing because EPA continued to claim authority to use generation shifting in future rules.

## Issues

1. Whether CAA § 111(d) authorizes EPA to set emissions limits for existing power plants based on BSER defined as sector-wide “generation shifting” away from coal and toward natural gas and renewables.
2. Whether this assertion of authority triggers the major questions doctrine, requiring clear congressional authorization.
3. Whether the petitions were justiciable notwithstanding the CPP’s stay and EPA’s stated intent not to enforce the CPP as written.

## Decision

- The Court reversed the D.C. Circuit and remanded.
- The Court held that § 111(d) did not grant EPA authority to impose emissions caps predicated on the CPP’s generation-shifting approach.
- The Court applied the major questions doctrine, concluding the CPP involved an assertion of regulatory power with substantial economic and political significance for which clear congressional authorization was required but absent.
- The Court rejected mootness and standing objections, treating EPA’s continued assertion of similar authority as sufficient to warrant review.
- In dissent, Justice Kagan (joined by Justices Breyer and Sotomayor) would have upheld EPA’s authority, reading “best system of emission reduction” broadly and criticizing the majority’s reliance on the major questions doctrine.

## Legal Principles

- Under the major questions doctrine, when an agency claims power of exceptional economic and political significance—especially one that would restructure a major sector—it must identify clear congressional authorization.
- General statutory terms such as “best system of emission reduction” in § 111(a)(1), as incorporated into § 111(d), do not supply clear authorization for a generation-shifting program that effectively reorders electricity generation across the grid.
- Agency claims of transformative authority may be evaluated in light of statutory context, including Congress’s use of specific language elsewhere in the statute when authorizing market-based or sector-wide schemes.
- Historical regulatory practice can inform whether a claimed interpretation represents an ordinary application of delegated authority or a departure requiring clear congressional direction.

## Conclusion

The Court held that EPA lacked clear statutory authority under CAA § 111(d) to implement the Clean Power Plan’s generation-shifting framework and limited EPA’s ability to adopt comparable, grid-wide restructuring measures absent explicit authorization from Congress.


West Virginia v. Env't Prot. Agency, 597 U.S. 697 (2022)