RFA: Corn Ethanol Net Energy Improves

Joanna Schroeder

A new analysis from the Renewable Fuels Association (RFA) finds that the net energy balance of corn-based ethanol at dry mill ethanol plants averages between 2.6 to 2.8, a improvement over previous estimates. Recent estimates from the U.S. Department of Agriculture (USDA), found net energy gains between 2.1 to 2.3. However, RFA says its analysis uses more current dry mill energy use data than the USDA study; thus, explaining why its net energy balances are more favorable.

rfalogo1The net energy balance is a ratio of how much energy is required to grow the corn and produce the ethanol, and then transport the fuel to end users. For example, a ratio of 2.8, means every BTU of energy invested in the process to make and deliver ethanol results in 2.8 BTUs of available energy to the end user. (BTU is the acronym for British Thermal Energy, a measurement for energy.)

In February 2016, USDA issued its updated net energy balance report on corn-based ethanol, finding “[t]here has been a large improvement in energy balance since 1995, and a small but positive improvement since 2008.” The previous USDA report, conducted in 2010, was based on 2008-era data and found that the balance was 1.9–2.3. RFA’s analysis found that USDA used the same 2008-era dry mill energy use estimates for both its 2010 and 2016 reports.

According to RFA’s own analysis, “[t]he energy balance of the top-performing quartile of biorefineries is in the range of 3.2–3.4, which approaches the USDA estimate of 4.0 for an ideally situated dry mill producing wet distillers grains.”

RFA President and CEO Bob Dinneen commented, “As this new analysis shows, the U.S. ethanol industry has made tremendous efficiency gains in recent years. EPA should take note and update its lifecycle greenhouse gas modeling of corn-based ethanol under the renewable fuel standard to reflect these improvements. Today’s ethanol plants are achieving the levels of efficiency that EPA assumed wouldn’t occur until 2022.”

The RFA analysis used dry mill energy use data from two other widely respected findings to support its results — Mueller & Kwik (2013) and Christianson & Associates (2016).

biofuels, Ethanol, Ethanol News, RFA