Prices for credits started soaring when the Renewable Fuel Standard, which mandates escalating volumes of renewables be produced each year, began requiring production of more corn ethanol and other biofuels than America's increasingly energy-efficient cars need or can even handle. That led to another perversity of this market: Even when there is a glut of ethanol available, the price of biofuel credits can go up. Because fuel blenders can't absorb all the renewables the law requires they purchase, they go on the hunt for the type of credit Bernard was purporting to sell. Demand for these credits increases, and their prices go up.

Source: Los Angeles Times March 26, 2018 10:07 UTC