On June 30, the U.S. Supreme Court issued its opinion in West Virginia v. EPA. The court held that the U.S. Environmental Protection Agency (EPA) exceeded its rulemaking authority under Section 111(d) of the Clean Air Act in promulgating the 2015 Clean Power Plan (CPP). The majority found that the term "best system of emission reduction" does not include a regulatory scheme that requires shifting power generation from coal to natural gas and renewable or other zero-emitting sources. While a narrow holding, this decision will impact the Biden administration's coming regulations regarding power plants and many future rulemakings as well.