A fourth intake pipe for Enwave Energy Corporation’s deep lake water cooling (DLWC) system in Toronto expands the company’s reach in a growing city with increasing demand for low-carbon cooling.

The Toronto-based company's most notable project, DLWC is a district energy system that uses heat transfer technology to cool approximately 180 buildings in Toronto through a web of underground pipes.

Commissioned at a ceremony Thursday afternoon in Toronto, the three-kilometre expansion sleeves an intake pipe through an older pipe which flows into Lake Ontario and adds a bypass tunnel. It adds 18 megawatts (MW) of capacity, increasing the base load capacity of the DLWC to 60 MW.

The fourth line “give(s) us more capacity to be able to expand our system where density counts,” Enwave's CEO Carlyle Coutinho told Sustainable Biz Canada in an interview before the ceremony.

Currently, the DLWC system extends as far north as Queen’s Park, west to The Well and eastward to the East Bayfront. The expansion stretches the system's reach outside the downtown core to the north, east and west.

Construction on the project, which cost over $150 million, started in 2019, Coutinho said. With Toronto in a construction phase and more green investors taking notice, he sees opportunities ahead for his company.

Growing the DLWC system

The DLWC system uses a network of intake pipes located 85 metres underground that extend to Lake Ontario. Three pipes that run five kilometres into the Great Lake made up its infrastructure prior to the expansion. Cold water (around 4 C) from the lake is pumped to the Island Filtration Plant operated by Toronto Water, then moved to the John Street Pumping Station.

In a tour of Enwave's facility as part of the commissioning ceremony, Sustainable Biz Canada had the opportunity to see the heat exchanger system in the station — contained in a concrete chamber holding thick green and blue pipes that extend across the ceiling and floor, and navy blue tanks. Here, heat exchangers transfer heat between two systems which chill the water that goes to downtown buildings.

In the chamber, Enwave executives and elected officials chatted about the need to speed up construction and the Ontario government's announcement of procuring 5,000 MW of electricity capacity from a mix of fossil fuels, renewables and nuclear power.

Once it flows to the client's building, the water meets another heat exchanger system, which circulates cool water through the building's pipes. After the water has looped through the building, it returns to be recycled by Enwave.

Creating 'wins' for everyone

DLWC has helped save approximately 129,360 tonnes of carbon dioxide equivalent over 20 years, Coutinho said, by displacing Ontario’s electric grid that uses natural gas to generate power during peak demand times. Operating at scale helps cut costs, the company states on its website, and can reduce electricity use by around 80 per cent compared to a building chiller.

The fourth expansion will reduce greenhouse gas emissions by over 33,000 tonnes of carbon dioxide equivalent (tCO2e) over the next 10 years. It is expected to enter service soon, though no firm date has been set.

At the ceremony, Katherine Sparkes, Enwave's vice-president of grid solutions, said the expansion will allow for 40 additional downtown buildings to be linked to DLWC. Developers will find it easier to decarbonize, she added, and the fourth intake pipe creates "wins for building owners and occupants, the climate, the city and all Torontonians."

Notable buildings that connect to Enwave’s DLWC are: Union Station, The Well, Eaton Centre, Mount Sinai Hospital, Scotiabank Arena, The Taylor, Fairmont Royal York and many other downtown towers.

The fourth line was deemed necessary because the growth in Toronto is “significant”, Coutinho said. There is a “tremendous” need for housing and retrofits in the city, so the development means DLWC has value for the future of Toronto. He believes with more infrastructure spending and housing demand, there will be opportunities for growth.

New ways of building better and thinking about energy differently are also playing a part in the company’s growth, Coutinho said. Environmentally conscious investors and changing perspectives on development are encouraging adoption of sustainable cooling systems like DLWC.

District energy has a role in Toronto’s TransformTO climate action plan for net-zero by 2040, which includes the city aspiring to retrofit 80 per cent of its buildings with low-carbon energy sources like district energy.

Enwave’s widening network

Other than DLWC, Enwave heats buildings using geoexchange and waste heat recovery. Outside of Toronto, it has projects in Mississauga, Markham, London, Windsor and Charlottetown, with over 400 buildings connected to its heating and cooling systems.

Since it was founded in 1969 as the Toronto Hospitals Steam Corporation to heat hospitals, Enwave has journeyed through privatization.

Renamed Enwave in 1999, it was owned jointly by Ontario Municipal Employees Retirement System and Toronto, then acquired by Brookfield Asset Management in 2012. After a period of growth from 2012 to 2021 across North America, Coutinho said it sold parts of the company to form one Canadian entity and one focused on the U.S.

Projects under development now include:

• the Etobicoke Civic Centre, a 500,000-square-foot project that will use Enwave’s geoexchange system; and
• the Lakeview Village Development in Mississauga which will feature a wastewater heat recovery system.

Enwave is also looking to launch a grid solutions business as a “holistic energy solution” as electrification ramps up, Coutinho explained. Such a business would examine: “How can we effectively electrify the economy by creating the most value through energy — which is using it electrically and thermally pairing it with thermal storage and electric storage.”