INNOVATION¦
“These fuel cells are currently running at 47 percent efficiency. And, because this is an industrial site, Gills can take advantage of all the heat being generated, too—using it to heat water, evaporate water, and refrigerate or chill plant water. So, the system is actually running at about 80 percent efficiency and negligible emissions.” The emissions avoided by using fuel cells, plus the emissions avoided by not trucking away and land applying the onion waste, yields an approximate 15,000 ton-per-year reduction in the company’s carbon emissions. Since the fuel cells are designed to supply base-load power and do not ramp up and down quickly, Gills Onions is able to offset 100 percent of its base-load power costs. Therefore, the company is able to bring the power up and hold it steady 24/7. “In a large fresh-cut produce plant like Gills, there are high, around-the-clock refrigeration demands. You don’t ever want to lose the cold chain in maintaining fresh onions. This constant demand is now satisfied with the AERS process on-site,” Deaton says.
back comes fairly quickly,” he says. As the system’s project manager, Deaton says he is pleased with what has been accomplished, but he also says the work is not yet finished. Future plans include further reducing the carbon footprint through energy storage, water re-use, and extracting quercetin from the onion waste for use as an anti-oxidant supplement for humans.
Authors: Denise Johnston Vice President Marketing and Sales, Biothane LLC denise.johnston@veoliawater.com Kristina Gerber Project Manager, Biothane LLC kristina.gerber@veoliawater.com
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Quick Payback, Flexibility Gained The entire project cost $9.5 million. Deaton says the savings of $400,000 a year from eliminating waste hauling, $700,000 a year in deferred electricity costs, plus $2.7 million in incentives for the project from Southern California Gas Co. (as part of the state’s Self-Generation Incentive Program) and tax credits should enable Gills to receive a five-year payback. “Meanwhile, we’re working on another process to take the remaining 25 percent of the waste left after the grinding and pressing process and reduce that by half. This should add another 20 to 50 percent to energy production. When you’re offsetting Edison Power at about 12 to 13 cents per kilowatt hour, the pay-
OCTOBER 2010 | BIOMASS POWER & THERMAL 63