Lake Ontario is the source of Toronto’s drinking water, a recreational haven, and an important ecosystem. But did you know the lake is also a valuable renewable energy source for many of Toronto’s largest downtown buildings?
Our lake provides cooling to our downtown core through a district energy system. A district energy system uses underground pipes to pump steam, hot or cold water into a variety of buildings within a neighbourhood from a central energy plant. In the case of Toronto, cool water from the lake is pumped into a pumping station that harnesses the coldness of the water to provide cooling services to a variety of buildings in downtown Toronto.
Toronto’s system started operating in 2004 when district heating provider Enwave built the Deep Lake Water Cooling system with support from The Atmospheric Fund (TAF). The system provides renewable energy that cools over 80 buildings in Toronto’s core, saving 13,500 tonnes of carbon emissions every year. It’s a prime example of how low-carbon district energy (cooling or heating) can serve a cluster of buildings.
In July 2017, Toronto City Council committed to expanding district energy sites across the city through the unanimous adoption of the TransformTO climate plan. A number of exciting developments have happened since then, including March’s City Council decision to work with Enwave on the development of low-carbon thermal energy networks throughout the city.
To learn more about the expansion of district energy and its contribution to Toronto’s carbon reduction goals, TAF’s Policy Research & Advocacy Coordinator Emma Loewen spoke with Enwave’s Director of Sustainability Engagement, Julia St. Michael, about their plans.
Q: What are the benefits of district energy compared to conventional heating or cooling?
District energy is good for our climate as it reduces the consumption of natural gas and electricity for heating or cooling buildings. It’s also good for building owners as they can outsource complex operations and avoid capital costs for on-site heating and cooling equipment such as boilers and chillers. That also means lower staffing, maintenance and long-term asset replacement costs. District energy also provides resiliency as the systems are designed to ensure reliable delivery of energy. In addition, energy efficiency improvements through new technologies are achieved at a greater scale as they have an immediate system-wide effect, impacting the entire district energy system simultaneously (as opposed to replacing individual boilers or chillers with more efficient equipment).
Q: How important is low-carbon district energy to achieving Toronto’s climate goals?
Development of transformational, large-scale, low-carbon thermal energy networks is a fundamental strategy outlined in the TransformTO plan to help reduce Toronto’s emissions by 80 per cent by 2050. It’s a key approach to improve energy resilience and to ensure energy does not become a limiting factor for growth. District energy delivers economies of scale that allow large emissions reductions at a lower cost than individual building systems by tapping into less carbon-intensive fuel sources, such as geothermal, solar thermal, sewer heat, biogas, biomass, and Deep Lake Water Cooling. In addition, district energy allows flexibility to integrate different energy sources in a phased approach as the market shifts to low-carbon solutions.
Q: What is Enwave’s vision for the future of district energy in Toronto?
There is a trend in city building toward holistic planning that integrates land use, transportation, and community design to create “complete communities” – walkable and vibrant neighbourhoods that contain a mix of spaces for everyday life (homes, offices, schools, shops, entertainment, green spaces, etc.).
We envision a future in which energy is fully integrated into community design, and we’re seeing the start of that today. Toronto is a leading example: TOcore is a pioneering strategy that aligns planning for energy, mobility, community services the public realm in the city’s downtown core.
In the future, district energy systems will be evaluated during the early stages of community design and will:
- Encompass heating, cooling, and power;
- Be an ecosystem in which energy is shared between buildings, with each acting as both a source and user of energy;
- Empower community residents to contribute to the energy market, leveraging technologies such as blockchain;
- Provide resiliency centres for refuge during extreme weather events;
- Enable neighbourhoods to achieve net zero and energy plus targets.
Q: How quickly will we see progress towards this vision?
We have already begun laying the groundwork, for example through Enwave’s new Community Energy Planning Strategy. It addresses the paradigm shift across cities to integrated community designs built around people and their neighbourhoods. We are engaging with developers, the City of Toronto and other stakeholders early in the master planning process to incorporate concepts such as energy sharing, microgrids, and low-carbon heating and cooling solutions into their developments.
The community systems we are working on now will establish the model for transitioning to a low-carbon economy through district energy. Our current plan is that new system nodes will initially be focused on new developments or redevelopment areas, but over time, these systems will expand to existing buildings nearby. We plan to implement a gradual transition over the next 12 years to support district energy becoming the norm by 2030.
Q: What are the plans for the Deep Lake Water Cooling system expansion?
We have been focused on expanding the capacity and reach of our Deep Lake Water Cooling network for a number of years. Initiatives that have been undertaken include system-wide efficiency projects, investments in remotely operated and/or distributed plants, plus the design and construction of large-scale thermal batteries for off-peak storage, all of which has allowed us to achieve significant growth. We are also in the process of considering sustainably focused opportunities which include building additional intakes into the lake to expand capacity.
Q: How can we decarbonize existing legacy district heating systems?
Enwave’s legacy steam system in Toronto is essential infrastructure that supports our hospitals, institutions, commercial office towers, and residents. To decrease its carbon footprint, we will:
- Use more low-carbon fuels (renewable natural gas, biofuels, etc.)
- Integrate new technologies along with steam to increase the overall system efficiency
- Constantly improve plant efficiencies and develop innovative waste heat recovery strategies
- Improve building energy efficiency
Q: How can district energy be expanded to other GTHA municipalities?
We see great potential to expand to other municipalities in the Greater Toronto and Hamilton Area (GTHA). The region is growing quickly, and urban policy is calling for intensification, which works well with district energy. We are already planning systems in various cities across the region and these municipalities will be in good company as we plan district energy projects from coast to coast, across Canada.
