A secret cache of renewable energy is lurking in the sewers. The key question is how to coax it to the surface and put it to work in the battle against climate change.
There’s no mystery over how excess energy ends up below cities. Showers, hot waters and sinks all add hot water to sewers. In fact, the U.S. Department of Energy estimates American’s wash 350 billion kilowatt-hours of energy down the drain every year. For some perspective, that’s enough power for about 30 million U.S. homes.
The largest sewer heat-recovery project in North America is now under construction in Denver.
Over the next few years, a $1 billion remodel will turn the National Western Complex, home to the National Western Stock Show and Rodeo, into a hub for art, education and agriculture.
The project will add about a million square feet of new indoor space. All of it will be heated and cooled with a heavy dose of heat from sewer pipes below the 250-acre campus.
Brad Buchanan, the CEO of the National Western Center, said the project has already readjusted how he thinks about the best location for real estate. Big pieces of sewer infrastructure have long repelled development. In the future, he imagines builders might seek them out to save energy costs and avoid greenhouse gas emissions.
“It’ll be interesting to see if folks start to look at not just where light rail lines or good schools are located, but what’s the proximity to a large sanitary sewer line,” Buchanan said.#News#WastetoEnergy#Content#UnitedStates#Colorado
Pless said the biggest barrier isn’t technology — it’s helping developers rethink the size of their heating and cooling systems. Sewer heat recovery often works best as the heart of a district-sized energy system, where a central plant provides energy to a whole neighborhood or office complex.