Waste energy to be used to produce winter crops

Using hot water generally lost through evaporation from Purdue Univ.'s power plant, horticulture professor Cary Mitchell, said the heat could be used for winter vegetable production. Mitchell is developing a high tunnel structure that would use the water that cools the university’s coal-fired boilers. The water would be piped underground beneath the tunnels to heat the ground to a suitable temperature for vegetable production.
“That energy, the hot water created by cooling boilers, is usually just vented into the air,” Mitchell said. “This would put that energy to use.”
Mitchell, who received  a $75,000 grant from Walmart, is hoping to build at least one 30-by-96-ft. tunnel. Later phases of the research would include addition of heat-pump technology to increase air temperatures in the tunnels and heat engines that could convert low-grade heat to electricity for supplemental LED lighting.
Larry Whitlow, Walmart market manager for the West Lafayette, Ind., area, said the company is interested in the research as a way to cut some of its costs and benefit local communities.
“The high tunnel research ties right into two of our company's initiatives: sustainability and encouraging local economic growth,” Whitlow said. “We're finding that with sustainability, there's a cost savings. By selling local produce in our stores, there is less freight and shipping cost, and that keeps prices low for our customers.”