An unlimited source of renewable energy for heating and cooling buildings

Technology developed by International Wastewater Systems recovers the heat generated by sewage to meet the heating and cooling requirements of residential, commercial and institutional buildings, including Sechelt’s sewage treatment plant 0n B.C.’s Sunshine Coast. supplied

Who says you can’t make a silk purse out of a sow’s ear?

Metro Vancouver entrepreneur Lynn Mueller is proving it can be done by building a profitable business on that most basic of biological products: human waste. His technology of extracting the heat generated by sewage is saving clients around the world big dollars every year.

“Sewage is everywhere and it’s extremely efficient and reliable,” says Mr. Mueller. “The U.S. Department of Energy did a study in 2009 that determined that 350 billion kilowatt hours of energy go down the drain every year just from household uses.”

Mr. Mueller, who began his career as a refrigeration journeyman, was fascinated by the possibilities of capturing that heat and repurposing it. He co-founded the Port Coquitlam, B.C.-based International Wastewater Systems with veteran mechanical contractor Daryle Anderson.

Their first residential project was installed six years ago in a 60-townhouse development in North Vancouver. They have since installed the SHARC (short for sewer heat recovery system) in several Vancouver-area condo projects, a theatre in Richmond and a sewage treatment plant in Sechelt, B.C. Projects are currently underway in the U.S., Europe and Australia.

SHARC consists of a filter that segregates solids from sewage, a pump that pushes the filtered water through a heat exchanger, and heat pumps that extract the heat from the exchanger. That heat is used to heat the building, hot water or both, with the assistance of a computer control unit.

In summer, the process can be reversed with the heat pumps pulling heat from the building and transferring it back into the sewer water. The solids filtered from the wastewater are returned to the wastewater stream that flows into the treatment plant to be cleaned.

Capital costs for SHARC range from about $250,000 for a condo project to millions of dollars for industrial projects. At the recently completed Sechelt sewage treatment plant, recovering the heat from sewage generated by 8,500 Sechelt residents produces about $5 of energy for every $1 in operating costs. That energy is used to heat and cool the 1,790-square-metre plant.

“We have stumbled onto a real monster here,” says Mr. Mueller, adding that his company, a 2016 Clean50 award winner, has recently been publicly listed on the Canadian Securities Exchange.

“We’ve gone from a concept to distribution on three continents – North America, Europe and Australia.’’

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