http://hosted.ap.org/dynamic/stories/S/SEWER_POWER?SITE=WHIZ&SECTION=HOME&TEMPLATE=DEFAULTSALT LAKE CITY (AP) -- The question goes something like this: How many toilet flushes does it take to power a light bulb? There's really no answer, but Salt Lake City is exploring a pilot project that would convert sewer waste into energy to run a heating a cooling system in a downtown building, city water department official Jeff Niermeyer said.
It sounds gross, but should be perfectly sanitary.
The heat, Niermeyer explains, will come partly from solid waste, and mostly from warm water that runs in sewage pipes after draining out of toilets, showers and sinks.
The sewage temperature - between 55 and 60 degrees - combined with a constant ground temperature of about 55 provides a viable ground source for a heat-pump system.
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