U.S. government delays in rolling out renewable fuels policy have stymied some $13.7 billion in investments and have prevented advanced biofuels companies from meeting mandated target volumes, according to an industry group analysis.

The U.S. Environmental Protection Agency’s (EPA) slow rulemaking on the Renewable Fuel Standard program over the past two years has “chilled” an influx of capital needed to boost commercial production, according to the Biotechnology Industry Organization (BIO).

The Washington firm represents biotechnology companies like Abengoa Bioenergy and DuPont.

Production of advanced and cellulosic renewable fuels, which use plant waste as a feedstock, has failed to meet targets set by Congress in 2007, stoking debate over the policy. Corn-based ethanol represents the vast majority of renewable fuels in use.

The EPA has been late in meeting annual deadlines to set volumes of renewable fuels required to be blended into the transportation fuel pool, which critics say has created uncertainty throughout the industry. The agency is late in announcing mandates for both 2014 and 2015.

The EPA has to approve new ways companies have designed to qualify a fuel under RFS policy. Delays in that process have helped dry up funding, according to BIO.