About 95 percent of U.S. ethanol is made from corn, Cooper said. But that percentage could soon change because the Renewable Fuel Standard, established by Congress in 2005 and later expanded, caps the amount of ethanol produced from corn at 15 billion gallons.Dozens of non-corn ethanol plants are now being developed and constructed throughout the country, experts say. Other California projects involve producing biofuels from food processing wastes, remains from field crops and manure from the dairy and poultry industries. Across the U.S., plants are looking at converting wheat straw, municipal waste and wood pulp into biofuel. In central California, the bio-refinery would resurrect a crop that has nearly vanished. The birthplace of the sugar beet industry, California once grew over 330,000 acres of the gnarly root vegetable, with 11 sugar mills processing the beets. But as sugar prices collapsed, the mills shut down. Only one remains in the Imperial Valley. When the last local mill in Mendota closed in 2008, farmers formed a cooperative and tried â¿¿ unsuccessfully â¿¿ to buy it back. "We were left with a choice: Are we going to build our own sugar mill, which is expensive, or come up with something else?" said William Pucheu, a farmer from Tranquility who is part of the cooperative. The farmers flew twice to Europe to tour beet-based biofuel facilities. This month, Mendota Bioenergy LLC â¿¿ the company formed by the cooperative â¿¿ received a grant to build the demo plant, which will turn about 250 acres of beets into 285,000 gallons of ethanol per year. If it's successful, a commercial bio-refinery would be built in Mendota, capable of producing 40 million gallons of ethanol annually. The bio-refinery, to debut in 2016, would put a total of about 80 beet growers and 35,000 acres back into production. Both the demo plant and the commercial plant would run year-round and use beets grown by local farmers. The plants will also burn almond prunings and other wood waste to generate electricity for internal use and will convert some of those prunings into ethanol. They will process waste pulp from the beets to produce biomethane for compressed natural gas, and will produce fertilizer and recycle water for irrigation.