The debate over when courts should defer to agency interpretations of federal statutes continues. The latest volley came last week in Solar Energy Industries Association v. FERC, where the U.S. Court of Appeals for the D.C. Circuit deferred to the Federal Energy Regulatory Commission's interpretation of a law benefitting small renewable power facilities—over one judge's vigorous dissent.

Solar Energy Industries is the most recent judicial battle over how to apply the U.S. Supreme Court's landmark decision in Chevron U.S.A v. Natural Resources Defense Council, 467 U.S. 837 (1984). Chevron held that courts should defer to a federal agency's reasonable interpretation of a statute when the statute is ambiguous or silent on an issue. Chevron also noted that, to decide whether the statute speaks to the issue (or instead is ambiguous or silent), courts should employ traditional tools of statutory construction.