Cellulosic ethanol's highly subsidized failure

Actual U.S. production of cellulosic ethanol and other cellulosic liquids compared to the targets for cellulosic biofuels specified in the Renewable Fuel Standard

Cellulosic ethanol, once a great green hope for cutting petroleum use and CO2 emissions, has been a bust. The chart above compares the volume of cellulose-based liquid biofuels (largely ethanol) actually used in the United States to the targets for such fuels set by Congress when it expanded the Renewable Fuel Standard (RFS) in 2007. Note the logarithmic scale on the vertical axis; the gap between promise and reality is so large that actual production would be barely visible on a linear scale. 

The fuel has been delivered at levels of no more than about 0.1% of (three orders of magnitude less than) the volumes on which the RFS was premised [1]. This chart does not include cellulosic biogas, which EPA re-classified to qualify for RFS compliance purposes and has seen recent production of around 500 million ethanol-equivalent gallons. However, such "renewable natural gas" is not in the spirit of the law, which envisioned liquid biofuels that could be readily used in motor vehicles. The 2019 RFS target for cellulosic biofuels was 8.5 billion gallons, set to reach 16 billion gallons by 2022. But in 2019, before the pandemic-related drop-off in 2020 for nearly all forms of energy, only 9.8 million gallons of cellulosic ethanol were tallied by EPA.