Enwave commissions Deep Lake Water Cooling system expansion

Toronto’s celebrated Deep Lake Water Cooling (DLWC) System, already the largest of its kind in the world, just got bigger as Enwave Energy Corporation celebrated the commissioning of its fourth intake installation.

Construction on the expansion of the 20-year-old DLWC system began in 2021 and involved laying three kilometres of pipe into Lake Ontario. The pipe draws water that’s as cold as 4 C through a new tunnel that runs under the Toronto harbour into Enwave’s John Street Energy Centre. New heat exchangers were also installed as part of the $100-million project.

Cooling capacity spikes 60 per cent

The expansion has increased Enwave’s cooling capacity by 60 per cent, with the capability of providing service to an additional 40 buildings throughout Toronto’s downtown.

“There is absolute simplicity in what we’re doing, which is bringing water in from the lake, very, very cold, pumping it around the city effectively, to use it as cooling,” explained Enwave CEO Carlyle Coutinho.  “What you do see here are big pumps. But that’s it. It’s pumps and pipes.

“So the simplicity of it is actually timeless.”

The DLWC services more than 100 buildings in downtown Toronto, cooling hospitals, commercial buildings, residential buildings, data centres, City Hall, entertainment venues – even Queen’s Park, an early subscriber.

With the expansion, the system is estimated to save 220 million gallons of water annually and avoid drawing over 60 megawatts of peak electrical demand from Ontario’s grid.

Enwave owns and operates the DLWC systems and shares infrastructure with the City of Toronto’s water utility, Toronto Water. The city and Enwave operate under an Energy Transfer Agreement that supports the transfer of cooling energy from the city’s drinking water infrastructure into Enwave’s District Energy Supply through heat exchangers.

The United Nations under its United 4 Sustainable Smart Cities initiative published a case study of Enwave’s DLWC system in A Guide to Circular Cities, praising its water consumption, energy efficiency and cost savings.

During the commissioning ceremony recently, Coutinho noted the project has been in the works for 15 years and recalled a conversation he had with Lou Di Gironimo, now acting deputy general manager with Toronto Water, in 2019.

“You said to me, ‘putting another pipe in, it’s not going to be as easy as the first time,’” Coutinho said, addressing Di Gironimo. “It’s going to be difficult.

“You told me that you think deep lake water cooling is an amazing system that has so many environmental benefits. And you told me you’re committed to helping us get this project done.

“And Lou, you were so very right. It was not easy. This project is ambitious and it’s impactful.”

Finding solutions

Coutinho also praised by name the contributions of key contractors and subs and their principals – BTY, Modern Niagara, WSP, Armstrong, C&M McNally Tunnel Contractors, Sprint Mechanical and Trivolt.

“You faced obstacles you’ve never encountered before,” he said. “You found solutions to get the job done safely, weathering the challenges of drilling a three-kilometre tunnel 300 feet below surface during the pandemic and atypical ground conditions.

“You’re the type of partners that don’t require more than a handshake for us to know that the job will be done right and it’s going to be done fairly.”

Another major project undertaken by Enwave recently was the installation of an 8.5-million-litre temperature-controlled tank underneath the lowest parking level of The Well, at Spadina and Front Streets. The tank employs a thermal battery fed by the DLWC system, storing energy at night during off-peak times and discharging during peak times.

Toronto Mayor Olivia Chow commented on that project: “Not only is the building beautiful, fascinating and gorgeously designed, this (8.5-million-litre storage facility) supplies low-carbon heating and cooling to 17 million square feet of living, working and retail space. That’s just one example on how Enwave is leading the way to decarbonize the downtown.”