Energy issues will take center stage this week as the Supreme Court addresses the Environmental Protection Agency’s greenhouse gas regulations and Senators Jeanne Shaheen (D-NH) and Rob Portman (R-OH) reintroduce their energy efficiency package.

The U.S. Supreme Court heard oral arguments for an uncommon 90 minutes February 24 in a case over the Environmental Protection Agency’s implementation of its greenhouse gas emissions regulations. The case, Utility Air Regulatory Group v. EPA, hinges on whether the agency’s decision to regulate mobile emissions triggers regulations under the agency’s prevention of significant deterioration permitting program, which requires permits for new stationary facilities and those undergoing major modifications, and, if so, whether the agency was legally justified in its efforts to narrow the regulated scope.

Justices seemed to lean toward deferring to the agency to do what it considered best under the statute, but appeared split on whether the agency’s course of action was the best choice. The court’s decision is not expected to undermine the agency’s overall authority to regulate greenhouse gases, but the lawsuit could provide an opportunity for the court to issue guidance on how federal agencies should interpret federal statutes.

For more on the latest energy and clean technology regulatory and legislative developments please see ML Strategies’ most recent Energy and Environment Update.