The City of Ottawa is among a group of partners that are working to deliver an innovative heat-energy project at the LeBreton Flats redevelopment.

The Sewage Energy Exchange System (SEES) project is being driven by the LeBreton Community Utility Partnership, a joint venture between Envari Holding Inc. (a subsidiary of Hydro Ottawa) and Theia Partners. 

This project will harness the untapped thermal potential of wastewater to provide sustainable and efficient building heating and cooling to the planned Odenak mixed-use development.

The SEES utilizes highly efficient heat pumps to transfer thermal energy to and from wastewater for heating and cooling buildings at LeBreton Flats. The system, which is the first of its kind in Ottawa, will operate entirely without fossil fuel, marking a significant step towards a cleaner energy future for the city.

The proposed SEES will divert sewage from the city’s collection system into an external well, then filter it to remove large solids and pump it through a heat exchanger to draw energy for either heating or cooling. After, the pumped sewage will be discharged back into the municipal sewer.

“This partnership demonstrates how we can use existing infrastructure in new and innovative ways to reduce emissions and support sustainable growth in our communities of the future,” said Ottawa Mayor Mark Sutcliffe. “By turning wastewater into clean, efficient energy, we’re taking a practical step that shows what’s possible when innovation meets sustainability in city building. This is great for the environment and for a clean future in Ottawa.”

Once completed, the SEES will provide more than 9 MW of heating and cooling capacity for approximately 2.4 million sq ft of development.

By utilizing this system, the LeBreton Community Utility estimates a reduction of approximately 5,066 tonnes of greenhouse gas emissions annually compared to traditional buildings relying on boilers and chillers. That volume is the equivalent of the electricity used by more than 3,300 homes for a full year.

The project also advances the City of Ottawa’s goal of reducing community greenhouse gas emissions by 96 percent by 2040, as outlined in its Climate Change Master Plan and Energy Evolution.

Construction to connect to the City’s sewer infrastructure is slated to begin later this year, following a collaborative design phase between the City of Ottawa and the LeBreton Community Utility partners.

Odenak is anticipated to welcome its first residents in 2027 and will utilize approximately one-third of the SEES system’s total capacity.

The LeBreton Community Utility Partnership is also engaged in discussions with the National Capital Commission to explore the potential for the SEES network to serve additional land parcels at the LeBreton Flats redevelopment and take advantage of economies of scale.

There are SEES projects operating in Europe, the United States, Toronto and Vancouver, with other Canadian ones planned.

City of Ottawa staff are part of a working group with other municipalities to share and exchange ideas as they collectively start using these systems.