What do you do with 150 tons of onion waste per day?
If you're Gills Onions, the U.S.'s largest producer of fresh onions, you buy two fuel cell power plants and make electricity, that's what.
Last Friday, the Oxnard, Calif., company unveiled a waste-to-power fuel cell generation plant that will annually cut $700,000 from its electricity bill and $400,000 in onion peel and shavings disposal costs.
Here's how the system works: The onion waste is pressed into juice and animal feed. The juice is then digested by bacteria, or fermented, a process that releases methane gas. The methane, instead of being burned, goes into two fuel cell power plants that produce a combined 600 kW of electricity -- enough to meet half the company's power needs.
Gills had bought the fuel cells in August 2006 from FuelCell Energy, a company that manufactures stationary fuel cell power plants and is based in my home state of Connecticut.
The entire system cost $9.5 million. Southern California Gas and the state government provided credits of more than $3 million. Gills expects the plant will pay for itself in under 6 years. After that, the savings drop straight to the bottom line.
By converting farm waste to energy, Gills Onions will eliminate about 30,000 lbs. of carbon dioxide-equivalent gases from the air. It will also conserve land and water that would otherwise have been used in disposing and composting the waste.
(Photo of the two fuel cell power plants © Deaton & Associates LLC.)