A new brief from the U.S. Energy Information (EIA) illustrates just how dramatically corn ethanol efficiency has increased in a very short time.
Today in Energy notes that last year fuel ethanol production in the United States reached an all-time high of 14.3 billion gallons of ethanol fuel. “The growth in U.S. fuel ethanol production has outpaced growth in corn consumed as feedstock—as the industry has grown, it has become more efficient, using fewer bushels of corn to produce a gallon of ethanol.”
If ethanol plant yields per bushel of corn in 2014 had remained at 1997 levels (when ethanol made up just 1% of the total U.S. motor gasoline supply), the ethanol industry would have needed to grind an additional 343 million bushels, or 7% more corn, to produce the same volume of fuel. To supply this incremental quantity of corn without withdrawing bushels from other uses would have required 2.2 million additional acres of corn to be cultivated, an area roughly equivalent to half the land area of New Jersey.
The article credits the yield increases to several factors including increased plant scale which has allowed producers to incorporate better process technology, such as finer grinding of corn to increase starch conversion and improved temperature control of fermentation to optimize yeast productivity. Additionally, the development of better enzymes and yeast strains has led to improved output per bushel of corn.