WATERLOO, Iowa — Ethanol supporters say they're encouraged by the results of a recent study refuting the notion that it takes more energy to produce ethanol than the corn-based fuel saves.

Scientists at the University of California-Berkeley say there's a 20 percent net energy gain by using fossil fuels to make ethanol compared to gasoline.

Ethanol producers say the study should be enough to convince skeptics that cleaner-burning ethanol is good for both the environment and the economy.

Consumers who were unsure about using ethanol-blended fuels may become new customers, producers say, and Iowa could reap major benefits as one of the nation's top corn-growing and ethanol-producing states.

"The new study reaffirms what we already know: Ethanol is energy positive, and it grows," said Bruce Rastetter, CEO of Hawkeye Renewables in Iowa Falls.

The company has plans to produce 100 million gallons of ethanol at a plant it's building in Fairbank, and it will double the size of its Iowa Falls plant to the same capacity.

The study results are especially positive for supporters of E85, a blend of 85 percent ethanol and 15 percent gasoline.

Currently, very few vehicles on Iowa's roads are built to burn E85, but advocates say the alternative fuel has too many positives for its use to remain small-scale.

Supporters say ethanol-blended fuel tends to be less expensive than regular unleaded gasoline, the auto industry has started marketing more cars and trucks capable of using E85, Congress has passed renewable fuel standards that increase the use of ethanol and grant money is available to help install E85 pumps.

Iowa has 21 ethanol plants and six more are under construction or expanding, according to the Iowa Renewable Fuels Association. The state produces 1.1 billion gallons of ethanol, but that is expected to soon increase by nearly 600 million gallons.

Lucy Norton, the association's managing director, said she hopes the study puts the question of whether ethanol is worth producing to rest.

As farmers become more efficient and production methods improve, the net gain in energy will only increase, she said.

Alex Farrell, co-author of the latest study, said previous research didn't take into account ethanol byproducts such as distiller grains and corn oil. Corn turned into ethanol also feeds animals and is used for other purposes, he said, which displaces competing products that require energy to make.

"Studies with a negative impact ignored that," Farrell said.

Since the latest research wasn't funded by any special interest group and used the most up-to-date data, Farrell said his group's information is the most accurate.

Just two percent of the gasoline sold in the United States in 2004 -- 3.4 billion gallons -- was blended with ethanol. The study said ethanol could supply 20 to 30 percent of fuel used nationwide.

"We focused on energy, not the farmer," Farrell said. "It's crystal clear transparent that it (the study) may help Iowa farmers."

Source: Associated Press