City of Toronto: Waterfront Neighbourhood Centre - Lake-based Geoexchange System

The City of Toronto is conducting a deep-energy retrofit for a combined community centre and school located on the downtown waterfront of Lake Ontario. The facility, called the Waterfront Neighbourhood Centre (WNC), was constructed over 20 years ago and is owned by the City. The City of Toronto is seeking GMF support for the portion of the project focussed on the closed-loop lake-based geoexchange system. They will conduct a number of other retrofits on the building which includes replacing current lights with LED, upgrading the building automation system, and adding rooftop solar PV combined with battery storage. After all retrofits have been completed, the anticipated reduction in energy use for the building will be 67% and the reduction in associated GHG emissions will be 78%. The City will mitigate potential adverse environmental impacts by utilizing food-grade glycol for the geoexchange system, which won't damage the lake if it leaks. They have also determined that the heat discharged during cooling season will have a negligible effect on lake temperature. The pilot project supports the City’s targets to reduce community-wide GHG emissions by 80% by 2050, and retrofit all City buildings to reduce energy consumption by 40% by the year 2040. It also offers many elements – both technical and procedural – that could be replicated at the City level and beyond. Compared to the Enwave system, which only provides deep lake water cooling from Lake Ontario, this geoexchange technology provides both heating and cooling. Solar PV is also uniquely suited to the waterfront in Toronto, where buildings closest to the water’s edge have a guarantee that another, taller building cannot be built to the south to shade panels. Large-scale adoption of PV-storage systems could help reduce strain on the city's electricity distribution grid, and increase its resilience in emergency situations. With extensive development planned and underway along Toronto’s waterfront, there are numerous opportunities to replicate both the proposed approach. The project also showcases the integration of the City’s State of Good Repair programs with energy retrofit project, by replacing elements of the building that are approaching their end of life with greener technologies, which will be used to underwrite the cost of measures with lower cost savings. The project was developed in consultation with numerous stakeholders, including the building occupants, the Regional Conservation Authority, and TRCA's Sustainable Technology Evaluation Program. Engineering students from the University of Toronto helped initiate the project by conducting an energy audit of the building last year, and will be involved in the retrofits. The project offers significant knowledge value in respect to integrating environmental targets with best practices in building maintenance, as well as piloting the use of new technologies. (Project description from original funding application)