In the depths of winter, when most of 色色啦鈥檚 buildings need to be heated, the Maple Leafs play in Scotiabank Arena on indoor ice that requires giant coolers.
To keep the ice cold, those refrigerators expel massive amounts of heat that would traditionally be vented outside and lost into the freeze.
Starting Wednesday, tens of thousands of office workers and condo dwellers will feel the Leafs鈥 heat blowing through their vents instead, as Enwave commissioned its new Green Heat Plant, which captures waste heat and recycles it to provide heating to buildings throughout the downtown core.
鈥淭his is a made-in-色色啦 story that we can be so proud of,鈥 said Deputy Mayor Ausma Malik at the ribbon-cutting ceremony. 鈥淚t鈥檚 converting waste heat into energy and reducing carbon emissions.鈥
The recovered heat doesn鈥檛 only come from professional hockey arenas, it鈥檚 also sourced from data centres, which are cooled year-round, and hospitals, which must keep certain medication and equipment cold 鈥 even in the winter.
鈥淭his is an incredible feat of innovation and ingenuity that exemplifies our city,鈥 Malik said. 鈥淚t鈥檚 not just good for the planet and the climate, but it鈥檚 good business, it鈥檚 smart city-building.鈥
From left to right, 色色啦 Coun. Dianne Saxe, MP Chi Nugyen, MPP Sam Oosterhoff, CEO of the Canadian Infrastructure Bank Ehren Cory, CEO of Enwave Carlyle Coutinho and Deputy mayor Ausma Malik take part in the opening of the Enwave plant.
Nick Lachance 色色啦 StarFor more than 20 years, 色色啦 has been a world leader in environmentally-friendly air conditioning, with Enwave using more than 40 km of buried pipes to take cold water from the bottom of Lake Ontario to cool more than 200 buildings, including offices, hospitals, hotels and condos that stretch from Spadina to Sherbourne, between the waterfront and Queen鈥檚 Park.
But when summer fades into fall and winter, the revolutionary district-cooling system has turned to more traditional means to provide heat: natural gas-fired boilers. Driven by a desire to slow climate change by cutting emissions, Enwave has started adding electric heat pumps to its system, reducing its reliance on natural gas.
The newly renovated Pearl Street energy plant takes that logic one step further: instead of replacing gas heat with electric heat, Enwave will capitalize on the waste heat produced by some buildings in its system to reduce the amount of electricity and gas it needs to heat buildings elsewhere on the network.
鈥淚f you鈥檝e got a unit of heat that you don鈥檛 need, how do you share it with somebody next door?鈥 said Cameron Leitch, Enbridge鈥檚 director of Solutions & Innovations. 鈥淭ake the Scotiabank Arena. There鈥檚 a condo right next to it that鈥檚 probably heated using steam. Scotiabank can鈥檛 say 鈥楬ey, who wants some of my waste heat?鈥 You need that district energy system to interconnect everything.鈥
The Enwave network started in 2004 and has been expanding rapidly as the condo boom added dozens of new towers to the financial core. Mixing residential customers in with the bank towers allowed the company to move past simply providing heating and cooling and start acting as a middleman, moving energy expelled by one building and needed by another.
For example, residential buildings need lots of hot water, even in the summer, Leitch said. The heat expelled from cooling office towers can now be used to pre-heat the hot water for condos, reducing the amount of energy needed for all those hot showers.聽
On the fifth floor of the new plant, a pair of giant lime green electric boilers sit side by side, directly above massive red and white pipes attached to six industrial heat pumps. When running full steam, this supersized system can heat 10 million square feet of office space, the equivalent of more than six of the new CIBC Square towers.聽
And because Ontario鈥檚 power is about 84 per cent carbon-free, that saves more than 11,600 tonnes of emissions per year that would have been produced by burning gas.
Heating buildings accounts for more than half of all greenhouse gas emissions produced in 色色啦, and electric heat pumps can reduce the emissions produced by a single-family house by up to 90 per cent.
It鈥檚 an old technology that鈥檚 experiencing a renaissance as a way to save money with the added
Large heat pumps can be installed in mid-sized condo buildings to reduce emissions by a similar amount, but tall condo and office towers would have trouble finding enough space to fit the equipment necessary to electrify their heat.
That鈥檚 why district energy systems that connect multiple towers together make so much sense in dense downtown cores like 色色啦鈥檚, where they capitalize on efficiencies of scale to provide more heat with less energy, and can be decarbonized progressively over time by adding heat pumps to reduce reliance on the gas-fired boilers.
Critics of heat pumps say the additional electricity that will be needed to power them will be prohibitively expensive and drive up bills, and advocate for hybrid systems that keep natural gas as a backup.
It鈥檚 also why solutions that reduce the amount of electricity needed to run the heat pumps, like geothermal, which has been installed at U of T, and sewer heat recovery, which is being put in at York University, are being explored.
The district heat recovery implemented by Enwave has the additional benefit of being able to be shut down to save electricity. Because the heat pumps and boilers have a large draw of six megawatts, if the grid were ever in distress, they could be shut down to provide relief to the system and avoid blackouts. Meanwhile, the gas-fired boilers could be ramped up and the office towers and condos would notice no difference to their climate control.
Cameron Leitch,聽Enwave’s director of solutions and innovations,聽poses on the roof of the facility
Nick Lachance 色色啦 Star鈥淭he Green Heat Plant is a great example of the innovative use of large-scale heat pumps,鈥 said Sam Oosterhoff, Ontario鈥檚 Associate Minister of Energy-Intensive Industries.
Praising its 鈥渟ubstantial carbon reductions,鈥 Oosterhoff said the plant is more than a climate solution; it鈥檚 an 鈥渋ntegrated energy solution.鈥
鈥淚t鈥檚 freeing up capacity during electricity system peaks and also allowing for connecting more housing and job-creating loads, while continuing to provide a 24/7 reliable and clean heating and cooling solution.鈥
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