Costs and benefits of producing cellulosic ethanol
NO FOOD CROPS:
Nationally, about 5 billion bushels of corn go into ethanol production annually, about 40 percent of U.S. corn production. Food companies, livestock producers and others have complained that corn-based ethanol makes food more expensive for consumers, especially when drought or other difficult growing conditions limit corn supplies and push up costs. Development of cellulosic ethanol from corn residue left after harvest will boost the supply of renewable energy without pulling from food markets. (Ethanol supporters frequently note that about 35 million metric tons of distillers grains — a high protein ethanol byproduct that's fed to livestock — are produced annually.)
LOWER GREENHOUSE GAS EMISSIONS:
Using cellulosic ethanol in your tank is expected to reduce greenhouse gas emissions 86 percent when compared with gasoline. Conventional ethanol creates about 20 percent less greenhouse emissions than a gallon of gas, government research shows.
Harvesting some of the corncobs, husks and stalks after harvest generates new income for farmers, who face declining commodity prices. Farmers in Emmetsburg are expected to get $60 to $70 for each bone-dry ton of stover.
IMPACT ON SOIL:
Environmentalists worry that too much crop residue could be removed in making cellulosic ethanol. Corn stover provides critical nutrients and helps prevent soil erosion.
The government has spent hundreds of millions of dollars to underwrite development of the technology and processes to make cellulosic ethanol at commercial scale. Critics say the fuel should be able to compete in the marketplace without subsidy.
The government also intervenes in the market by requiring that biofuels account for a certain percentage of the nation's fuel supply. Cellulosic ethanol will struggle to compete with lower-cost corn ethanol, which is expected to be in oversupply if the federal government reduces the required blending level for biofuels.