Prices of renewable fuel credits slumped 35.7 percent in the first three months of 2018, their biggest quarterly loss in a year, on uncertainty over the future of U.S. biofuels policy. This has been the second straight year of uncertainty for the Renewable Fuel Standard (RFS), a 2005 law requiring fuel producers to blend increasing volumes of renewable fuels like ethanol with petroleum-based counterparts. Those who cannot blend these fuels are required to purchase credits, known as Renewable Identification Numbers (RINs). Those credits once cost just a few cents, but the price has risen with more ambitious requirements for biofuels use to cut greenhouse gas emissions. The RFS program, also aimed at reducing U.S. dependence on foreign oil and boosting rural economies, has expanded the market for corn-based fuels. But independent refiners have complained as the price of the credits at times has exceeded $1 […]