Studies have estimated that converting manure from the 95 million animal units in the United States would produce renewable energy equal to 8 billion gallons of gasoline, or 1% of the total energy consumption in the nation.
Now, researchers confirm that it is technically feasible to convert cow manure to electricity on farms, but the economic returns depend highly on the base electricity price; the premium paid for converted energy; financial supports from government and other agencies; and the ability to sell byproducts of the methane generation.
Read more at University of Vermont