His mind’s in the sewer - it’s a hot idea
Conservation: Technology would heat mansion using energy from waste pipes
By Heather May
The Salt Lake Tribune
November 4, 2006
Jeff Niermeyer, Salt Lake City’s second in command in charge of water, has a joke that goes like this: How many toilet flushes does it take to power a light bulb?
The city is searching for the answer - sort of.
It is embarking on a pilot project that would heat and cool a private business by using water warmed and chilled by a sewer line.
Sounds gross. But it should be perfectly sanitary.
The heat will come partly from the solid waste and mostly from the warm water that runs in sewage pipes - water that drains from toilets, showers, sinks.
Such sewage stays at a temperature of 55 to 60 degrees. Combined with the constant ground temperature of around 55 degrees, they both provide a viable ground source for a heat-pump system.
Such systems, simply put, transfer energy from one place to another.
“What I want out of the sewer is latent heat,” Jon Lear said Friday at the Major George Downey Mansion at 808 E. South Temple, which he is renovating into law offices. “I never see the sewage.”
Blame Hurricane Katrina for the idea.
Last September, Lear was deciding how to heat and cool the property when the hurricane hit the Gulf Coast and gasoline prices soared. “This is nuts,” Lear thought. “If it doesn’t last, this is still a picture of the future.”
He started exploring heat pumps, but didn’t like the traditional method of drilling holes into the ground to tap the heat from the aquifer.
It’s too expensive and impractical on a large scale. He initially wanted to use the city’s culinary system, but that was rejected.
Instead, the city suggested the sewer lines.
If his system is successful, Lear hopes it could be used by the masses.
Still, it’s expensive. He will spend $20,000 more than he would have with a traditional system.
He expects to recoup the costs in up to nine years because heat pump systems take up to 50 percent less energy to operate.
Ironically, the firm Lear owns with his brother specializes in oil and gas law. The newfangled system “salves our conscience,” he said.
In essence, Lear is benefiting from heat generated upstream. Some 17 to 20 gallons of water rush by the building every hour.
The system should sufficiently heat and cool the 8,000-square-foot building 90 percent to 95 percent of the time, Lear said. For the rest, he will have a pool of 1,800 gallons of water in his basement that will absorb the extra heat. That water will then be used to irrigate the lawn.
While the building will, in theory, be off the fossil-fuel grid (Lear is paying for wind power for his electricity), he will have to use some natural gas to warm the water for hand washing.
The city will pay $10,000 to install the steel pipe. City officials are intrigued because the system promises to reduce carbon dioxide emissions - about eight tons a year at the mansion after adjusting for the increased use of electricity to run the pumps and to treat the additional water. Lear plans to patent the technology but would grant the city a perpetual license to use the techniques on public buildings.
“There’s a lot more people getting to believe that the greenhouse-gas effect is really impacting our climate,” Niermeyer said.
“We’re going to have to think of more creative ways to wean ourselves off of hydrocarbons and [still] enjoy the quality of life we want to enjoy. It’s going to be [by] capturing these other alternative-energy sources.”
Already, the city is talking about using the sewer system to warm and cool the former Main Library when The Leonardo at Library Square opens in 2009. The library sits near a 30-inch pipe, compared to the standard 8-inch, carrying the equivalent of two Olympic-sized swimming pools full of water every day. “That’s a lot of heat,” Niermeyer said.
And someday, the city may be able to form an energy utility based on its sewer system.
As far as the city and Lear can tell, using sewer pipes as a source of energy in the way Lear has proposed is unique. Oslo, Norway, extracts heat from sewer lines, but uses a different system.
“I’m the guinea pig,” Lear said, standing outside the mansion. Referring to the replica of a coal cart that stands in the front yard, “That’s the old way.” Posted by: Paul on December 09, 2006 at 14:36:36