In Oxnard, California, an onion farmer, Steve Gill, has been using juice from the 40% of the discarded portions of onions that Gills Onions processes, about 150 tons of waste a day, to create energy to run refrigerators and lighting at the 14-acre plant.  By generating their own electricity from the waste of their production processes, the processing plant saves $700,000 each year on electricity costs plus another $400,000 a year on disposal costs.

With government assistance, Gills Onion recently installed a new $9.5 million system, which they expect will pay for itself in 6 years.  The system "converts methane from fermented onion juice into energy burned in two on-site fuel cells", according to an article in the LA Times.  It also eliminates up to 30,000 tons of carbon dioxide-equivalent emissions a year.  More and more processors are considering producing the biofuel they need to run their expensive operations from the waste they generate.

The process of extracting biofuel from anaerobic digesters, such as the one at the Gills Onions plant, is pretty interesting.  "Machines extract about 30,000 gallons of onion juice that is then sent to a 145,000-gallon holding tank kept at a toasty 95 degrees. Inside, bacteria purchased from an Anheuser-Busch beer brewery produce methane gas by feasting on the carbohydrates in the fermenting juice. . . The gas is purified, dehumidified and compressed, then burned in the fuel cells at temperatures that exceed 1,000 degrees. The 600-kilowatt system produces enough power to operate the plant's refrigeration units and lighting."

Steve Gill seems quite pleased to be taking responsibility for the waste that the family plant produces.  "I didn't want to depend on anyone taking my waste for me," Gill said. "It was my problem, and I had to solve it. It's a relief to find a solution."