‘It does not smell’: Wash. program to use sewage to keep businesses warm
Oct 31, 2023, 8:36 AM
(Photo by Wolfgang Kaehler/LightRocket via Getty Images)
King County is about to heat things up on a pilot program that will use sewage to keep businesses warm this winter.
The county’s first customer, a real estate equities company in South Lake Union, is keeping their 1.6 million-square-foot campus warm using heat from sewage.
It works because the sewage pipe transfers heat to the building’s pipes but the two never mix.
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“It does not smell,” Erika Kinno from King County Waste Management told KIRO Newsradio. “The system is completely sealed, so when it is up and operational, you should not smell it at all. If you were in a building that is being heated by wastewater, you shouldn’t have a clue at all.”
Warm and hot wastewater flushed from homes and businesses is a significant energy source. The U.S. Department of Energy estimated that 350 billion kilowatt-hours of heat energy are flushed down the drains in the United States every year — roughly enough to power 30 million homes.
“The Wastewater Treatment Division is the first in Washington state and one of the first wastewater utilities in the nation to offer sewer heat recovery (SHR),” King County’s website reads. “Private commercial property owners and developers can recover heat energy from our sewer pipes for heating or cooling their buildings. SHR technology is fairly common in Europe and parts of Canada, but standardized SHR use agreements are pioneering in the U.S.”
This technology captures a portion of wastewater in an underground holding tank, transferring its heat energy to a heat exchanger. This allows a heat pump to extract that energy and transport it to a connected building’s domestic hot water or heating or cooling system.
Repurposing this otherwise wasted heat energy resource is another way building owners can meet sustainability goals and positively contribute to climate action.
The county said sewage is a great source of renewable energy, one that they don’t want to go to waste.