A new development in Ottawa-Gatineau is capturing waste heat from a nearby paper factory for heating, using a district energy system that also channels chilled Ottawa River water to cool buildings in the summer.
Scott Demark, a partner with Theia Partners, the company that built the Zibi mixed-use development, said the idea for the system came to him when he noticed plumes of steam pouring out of smokestacks at the Kruger Products plant in Gatineau, Quebec, on cold winter days, CBC News reports.
Theia was building its new development “next door, practically,” Demark said. He recalled thinking, “How can we harness that and bring it here? It’s silly to be dissipating that to the atmosphere and turning around and burning gas or something to make heat.”
That line of thought led to the system that went online in 2021 to heat Zibi, a planned community located on 13.75 hectares/34 acres along the Ottawa River, a natural border between the provinces of Ontario and Quebec. The industrial lands were previously owned by the Domtar paper company, and for vastly longer have been a sacred place for the Algonquin people. Amid considerable controversy at the time, the original project developer, Windmill Development Group, entered into what the Algonquins of Ontario called “a landmark partnership that will see the preservation and promotion of Algonquin culture in the development of Zibi.”
Now, the mixed residential and commercial spaces at Zibi, which means “river” in Algonquin, will be home to more than 5,000 people and more than 6,000 jobs, according to the developer’s website.
“So far, 615,000 square feet of residential and office space on either side of the river are being heated with waste heat from the nearby Kruger Products Plant,” writes CBC News. The system is still growing, and will eventually heat four million square feet.
At the Kruger plant, natural gas is burned to heat water to make paper, then to dry it out. Following Demark’s inspiration, engineers from Kruger and Zibi partnered to transfer heat from the part of the process where, after making the paper, water at 25° to 30°C cools in a steaming “settling tank” before being returned to the Ottawa River. Using heat exchangers, that energy is now transferred to the water in the Zibi district heating network.
The tank water is eventually discharged into the river, while the heat is used in Zibi Community Utility’s central heating plant and directed to different parts of the system. In winter, heat from the warm water is extracted by water-source heat pumps in the Quebec-side Zibi buildings. In the summer, the water largely bypasses Kruger and exchanges heat directly with the Ottawa River to provide cooling.
Water is also diverted to the Ontario-side buildings through pipes mounted under the Booth Street bridge, though that water is also pre-heated on the Quebec side because Quebec’s electricity costs less and is produced with fewer emissions than power from Ontario’s gas plants.
Guy Faubert, an engineer and Zibi resident who lives in a 15-storey building on the Gatineau side, told CBC News the district heating system captured his interest and prompted his decision to move to the development. He is so far pleased with its performance, he said.
“I find the comfort inside my unit to be exceptional,” he said. “The system is very responsive and very effective and very quiet.”
Zibi’s developers say the arrangement with Kruger delivered the first system in North America to use post-industrial waste recovery in a master-planned community. More broadly, district heating and waste heat recovery systems have cropped up elsewhere. For example, the False Creek Neighbourhood Energy Utility near Vancouver uses waste heat from sewage, and another wastewater energy project is under construction at Toronto Western Hospital. Also in Toronto, Enwave Energy Corporation uses a deep lake water cooling system in Lake Ontario to air condition downtown buildings.
These initiatives are one option for decarbonizing energy systems in Canada, where heating residential, commercial, and institutional buildings accounts for 16% of energy use and generates 13% of energy-linked greenhouse gas emissions. Communities are increasingly considering how to reduce their reliance on high-emitting energy sources, and homeowners have turned to options like home retrofits and rooftop solar.
District heating systems can be powered by fossil fuels, but those that find alternative sources like Zibi’s industrial waste system are a viable way to reduce emissions from energy production, opening possibilities that go beyond what households can achieve on their own, CBC News explains.
