At the National Western Center, an unparalleled system is mining dirty water for clean energy. It’s the largest sewer-heat recovery project in North America.
You’re not alone if you read the word “sewer” and thought, “Wait, what?”
Yes, this green energy relies on raw sewage from thousands of homes and businesses in Denver – a great gush of wastewater expelled from dishwashers, washing machines, sinks, showers, tubs, and toilets. Sewage often is associated with its fecal content, but it contains something far more relevant to sustainable energy. That’s heat. Consider: An 8-minute shower typically uses a whopping 20 gallons of water at roughly 105 degrees Fahrenheit. With each load of laundry, a high-efficiency washing machine could gulp 13 gallons of water at up to 130 degrees. And, with each cycle, a dishwasher might use 4 gallons of water at 140 degrees. That’s a lot of water – and a lot of heat – down the drain.
In fact, the U.S. Department of Energy estimates that Americans send the equivalent of 350 billion kilowatt-hours of energy down our drains each year – enough to power about 32 million U.S. homes.
“It really is just wasted heat,” said Leslie Fangman, a civil engineer and vice president of corporate development for CenTrio. CenTrio is part of a consortium called EAS Energy Partners, which was selected by the National Western Center Authority and the city and county of Denver to finance, design, build, operate, and maintain the sewer-heat recovery system.