RFA Analysis Finds Improvement of Corn Ethanol Net Energy Balance

(Renewable Fuels Association/Ethanol Producer Magazine) An analysis conducted by the Renewable Fuels Association and released March 7 finds the net energy balance of corn-based ethanol at U.S. dry mill biorefineries averages 2.6–2.8, an improvement over previous estimates, reflecting efficiency gains.

The figures build on USDA’s recent findings of a 2.1–2.3 net energy balance. RFA’s own analysis uses more current dry mill energy use data than the recent USDA study, which explains why the RFA results are approximately one-third higher than USDA’s findings.

The net energy balance is a ratio of how much energy is required to produce the corn and ethanol, and then transport the fuel to end users. In simple terms, a ratio of 2.8, for example, 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.

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.” READ MORE / MORE Download report Download USDA report