Wastewater energy is a low-carbon emission heating and cooling solution for buildings. It can eliminate or reduce the requirement to burn natural gas to operate conventional mechanical equipment by using wastewater flows in the City’s sewer system as a source of renewable energy.
Warm wastewater originating from sources such as showers, laundry machines, toilets, dishwashers, and industrial processes constantly flow through the City’s sewer system. A large portion of the City’s sewer system contains a high wastewater flow rate at significantly high and constant temperatures that can be used as a renewable energy source for new and existing buildings, where feasible. Wastewater energy projects can recover this heat to use for heating or use it as a heat sink for cooling.
Wastewater energy projects reduce operational greenhouse gas emissions from buildings and support the City’s TransformTO climate strategy and target to reduce greenhouse gas emissions in Toronto to net zero by 2040.
The first wastewater energy project in Toronto is currently under construction at University Health Network’s Toronto Western Hospital on Bathurst Street. The project is being delivered by Noventa Energy Partners under an energy transfer agreement with the City. This project will connect to and utilize wastewater flows from the Mid-Toronto Interceptor sanitary trunk sewer for non-contact thermal energy exchange. The energy will be used to heat and cool the hospital’s buildings, reducing the hospital’s natural gas use by an estimated 90 per cent, equal to about 8,400 tonnes of CO2 output annually.
The Wastewater Energy Map is an interactive online map which shows the approximate heating and cooling capacities of sewers in the City of Toronto. Property owners and energy developers are encouraged to use the map to determine whether there is a sewer in the vicinity of their site that can potentially be used for a wastewater energy project.