Toronto’s Deep Lake Water Cooling System: Harnessing the Depths of District Energy for Large-Scale Decarbonization

In the heart of Toronto, a revolution is unfolding underground. Beneath the bustling streets and towering skyscrapers, a network of pipes is tackling the climate crisis. The story of Toronto’s Deep Lake Water Cooling (DLWC) system and its potential to reshape the approach to sustainable development was told during a session at the 2023 ULI Spring Meeting in Toronto.

The DLWC system is a testament to the power of district energy, a concept that emphasizes conservation through localization. Unlike central energy, which loses substantial power in transmission over long distances, district energy systems generate power locally. This approach reduces energy loss, minimizes pollution, and enhances efficiency, making it a powerful tool for decarbonization at the scale needed to achieve net zero greenhouse gas (GHG) emissions.

The panel discussion of this groundbreaking project brought together Fernando Carou, a manager with the city of Toronto’s Economic Development Corporation; Amy Jacobs, a senior vice president with Enwave; and Yichao Chen, a director with Cadillac Fairview. With Chuck Schilke of Johns Hopkins University as moderator, these panelists discussed the importance of district energy and the role of partnerships in achieving sustainable development.

Jacobs emphasized the benefits of district energy, saying it “enables efficiency. It enables reliability. It brings parties together to achieve a common goal.” This sentiment was echoed by Carou and Chen, and they all highlighted the importance of their organizations’ partnership in achieving their goals.

A Game-Changer

The DLWC system, considered the largest district energy system in North America, harnesses the cold water at the bottom of Lake Ontario to cool much of downtown Toronto. The system consists of a set of intake pipes that run three miles (5 km) into the lake and 272 feet (83 m) deep, where the water is cold year-round.

The system has reduced electricity use for chillers by 90 percent and saved 189 million gallons (714 million liters) of water that otherwise would be used in cooling towers. Seventy-five buildings in Toronto’s downtown core are currently connected to this system.

The Future of District Energy: The Pearl Street Plant

The Pearl Street steam plant, which is being expanded with a heat pump plant, will enable significant low-carbon heating in the city—the equivalent of converting 10 million square feet (930,000 sq m) of office space to net zero emissions.

As Toronto continues to evolve and tackle the climate crisis, work is underway on an expansion project for the DLWC. Enwave is adding a fourth intake pipe in Lake Ontario to run parallel to the existing system.

Springwater and Bloor-Kipling (Six Points)

The panelists highlighted the Springwater development, a single-family residential development in Markham serviced by a geo-exchange district system. The project was carried out in partnership with the city of Markham and Mattamy Homes. The homes save more than 90 percent of greenhouse gas emissions compared with traditional heating, ventilation, and air-conditioning systems.

The Bloor-Kipling (Six Points) development, serviced by a geo-exchange district with a central plant, is built to near net zero standards. A partnership with the city of Toronto, it provides GHG savings of more than 80 percent compared with traditional HVAC systems.

The Climate Emergency and Need for Decarbonization

As the panel drew to a close, all three panelists reiterated how important these ideas are in taking decarbonization to the level needed to address the climate emergency. “District energy gives you another tool in the toolbox to decarbonize,” Chen said. “Partnership is key. We’re doing our small part to get towards a better future.” Jacobs echoed that sentiment, saying, “What we’ve been able to do in Toronto is truly incredible.”

Real estate energy users in Toronto and beyond stand to benefit from systems like the DLWC. District energy systems are not just viable, but also essential tools for large-scale decarbonization.

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