In July, the U.S. Court of Appeals, District of Columbia Circuit ruled in favor of renewable fuels advocates, including the Americans for Clean Energy and the National Corn Growers Association, agreeing with the petitioners that the Environmental Protection Agency (EPA) erred in how it interpreted and used the “inadequate domestic supply” waiver in the Renewable Fuel Standard law in setting low renewable fuel volumes for 2014-2016.

The National Corn Growers Association stated that the “court decision is a win for farmers, the biofuels industry, and consumers. This ruling affirms our view that the EPA did not follow the law when it reduced the 2014-2016 renewable fuel volumes below levels intended by Congress. The court held that EPA was wrong to interpret the phrase ‘inadequate domestic supply’ to mean ‘inadequate domestic supply and demand.’ We agree with the Court that effectively adding words to the law through this interpretation simply exceeds EPA’s authority.”

U.S. Circuit Judge Brett Kavanaugh wrote that the EPA isn’t allowed "to consider the volume of renewable fuel that is available to ultimate consumers or the demand-side constraints that affect the consumption of renewable fuel by consumers.”

The court ruling is a blow to oil refiners, who have argued that there are constraints to blending the fuels into petroleum. The American Petroleum Institute said in a statement it was "disappointed" with the court’s decision, which the trade group said highlighted the need for congressional action to reform the renewable fuel standard - a move congressional analysts have said is unlikely to happen.