CASCADING GEOTHERMAL, A NEW NEW ENERGY

“Cascading” Geothermal Energy Could Revive Small Towns with New Green Jobs
Tina Casey, September 21, 2010 (Clean Technica)

"Part of a new U.S. Department of Energy grant for innovative geothermal technology is going to fund a project that could help small towns and mid-sized cities generate low cost local power, cut their carbon footprint, create new green jobs, and even develop local sources for fish and produce. The technology is called “cascading” geothermal because it uses and re-uses the same fluid in a series of applications…

"…[A] religious community called I’SOT…in Canby, California provides a textbook example…[It] is under development in partnership with the Department of Energy and the National Renewable Energy Laboratory. In 2006 the community began operating a geothermal heating system that provided heat and hot water for 34 buildings, but the effluent from that operation was simply filtered and discharged to a river…"

Schematic of "cascading" geothermal from Northern Arizona University (click to enlarge)

"Under the new project, the highest-temperature fluid will be used to generate electricity. After that, energy can still be extracted for additional space heating and hot water, operating up to ten acres of greenhouses, heating up to four 30-foot diameter aquaculture tanks, and for melting snow. The system may also provide enough energy to operate a new food storage and laundry facility…

"The Modoc Contracting Company – also of Canby – won the DOE grant…That $2 million is a modest amount compared to the impact it could have on communities across the U.S., as DOE estimates that in the west alone there are about 1,500 possible well sites in small towns and mid-sized cities with the potential to develop cascading geothermal projects. That in turn could create new green jobs in local aquaculture and greenhouse-based agriculture operations…"

Schematic of "cascading" geothermal from the International Gothermal Assoc (click to enlarge)

"If the concept of urban fish-farming seems a little far fetched, at least one expert has been successfully raising food grade fish in the middle of New York City, so cascading geothermal projects may have potential in larger cities where space is hard to come by. The possibility of developing add-ons and tie-ins with other forms of renewable energy could also help maximize the use of space…

"…[A] greenhouse operation powered by geothermal energy could converge with algae biofuel production, and an aquaculture pond could double as a platform for a floating solar energy installation."