‘We’re using the Earth as a battery’: how the University of Toronto is decarbonising its historic main campus

Jul 28, 2023

An ambitious infrastructure project at the university hopes to show other heritage sites around the world how to balance energy transformation with architectural preservation

Illustration of the new Front Campus above the geo-exchange: people enjoy green grass edged with leafy trees.
Car parking has been replaced with gardens covering boreholes for geothermal exchange

This article was originally published on theguardian.com as part of the University of Toronto and Guardian Labs What’s Next? Ask Toronto campaign.

Renowned for its evocative Romanesque and gothic revival buildings, the University of Toronto’s 195-year-old St. George campus is one of the historic showpieces of Canada’s largest city. At its centre is King’s College Circle, the campus’s main open space, and the principal site of what the university describes as one of Canada’s most ambitious sustainable infrastructure plans: the Landmark Project, which aims to remove the campus’s asphalt parking and replace it with granite pathways and gardens to encourage conversation, study and relaxation.

“Driving and parked cars used to form a barrier between King’s College Circle and the buildings around it. We are taking away the cars, but we also have to be a good neighbour and re-provide some of the parking spaces underground,” says Prof Scott Mabury, the university’s vice-president for operations and real estate partnerships. “The project puts our university community at the centre of this heritage landscape. It will deliver a flagship infrastructure in our sustainability strategy, but also a key public open space.”

The excavation of the car park to create more green space has presented the university with an opportunity to decarbonise the heating and cooling systems of surrounding buildings using the Earth’s below-ground natural heat, via an engineering practice known as geo-exchange.

“Traditional geothermal technology relies on the Earth itself providing heat,” says Ron Saporta, who, as an engineer and chief operating officer for property services and sustainability at the university, is overseeing the project. “In somewhere like Iceland, heat is relatively close to the ground, but in Ontario you would have to dig miles deep [to access it]. Instead, geo-exchange uses the Earth as a battery.”

The project puts our university community at the centre of this heritage landscape. It will deliver a flagship infrastructure in our sustainability strategy, but also a key public open space.

By excavating relatively shallow boreholes, it’s possible to reach layers of the Earth’s crust with very stable temperatures throughout the year. “For the Landmark project we are excavating over 350 boreholes 240-metres deep. With the help of heat pumps, we can use these to store excess heat underground in the summer and retrieve it in the winter,” says Saporta.

According to Mabury, the project is the single largest contributor to the university’s path to net positive by 2050, saving 15,000 tonnes of CO2 from St. George campus’s current footprint of 91,000. Ultimately, the Landmark project will not only deliver cleaner energy to cool and heat the campus, but also give the university’s most iconic green space back to the community.

The project puts our university community at the centre of this heritage landscape. It will deliver a flagship infrastructure in our sustainability strategy, but also a key public open space.
Aerial view on construction of the geo-exchange on Front Campus. Cranes install pillars in a huge dig.
Construction underway on the University of Toronto’s Landmark Project

“King’s College Circle is at the very heart of U of T,” says David Palmer, vice-president, advancement and interim vice-president, communications. “Many of our alumni have fond memories of this space and are championing the creation of a more sustainable and more inviting version that will become part of the university experience for generations to come.”

Many of our alumni have fond memories of this space and are championing the creation of a more sustainable and more inviting version that will become part of the university experience for generations.

Mabury says that the university’s sustainability strategy was bolstered by reaching out to the community early on in its development: “We invited architects and engineers to pitch for the project at town hall meetings. We held meetings outdoors, and managed to get a community of 100,000 students and staff to come together around the project from the beginning.”

An important part of the project’s remit is to preserve the campus’s historic architecture, which is why, says Saporta, the retrofits to most buildings are limited to services such as radiators, keeping the most heritage-sensitive campus buildings untouched.

Many of our alumni have fond memories of this space and are championing the creation of a more sustainable and more inviting version that will become part of the university experience for generations.

Perhaps counterintuitively, it is not the university’s oldest buildings that are always the least efficient. “Our property team found that 1960s buildings, constructed at a time when oil was cheap, often performed worse,” says Mabury. “We have already replaced windows and improved insulation in many of these buildings to drive down their energy use.”

The university expects its geo-exchange infrastructure to play a part in reducing the campus’s carbon emissions, but Saporta sees its potential beyond just this institution: “I see the biggest impact as inspiring the university’s 70,000 students to take this project and what they learn from it elsewhere. Many of the [geo-exchange] plant rooms will have glass walls, so you can see into them, and one of them has been designed to host lectures for up to 20 students.”

In addition, colour coded pipes and information displays will explain the principles of the systems to the public. With this, the university aims to inspire future generations of graduates to deploy these and other decarbonising technologies elsewhere in Toronto and beyond.

I see the biggest impact as inspiring the university’s 70,000 students to take this project and what they learn from it elsewhere.

On completion, the University of Toronto claims the Landmark project will be the largest urban geo-exchange system in Canada. But can this technology work in the UK? Saporta is enthusiastic about the possibilities.

“Geo-exchange was initially developed in Europe and it can work in a more temperate climate like the UK’s. The key is the economies of scale,” he says. “We can make this project work by digging many boreholes to provide heating and cooling to over 200 buildings.”

I see the biggest impact as inspiring the university’s 70,000 students to take this project and what they learn from it elsewhere.

Asked about the U.K.’s current programme to replace gas boilers with heat pumps, Saporta agrees with the principle: “Heat pumps are much more efficient machines than gas boilers, however there is nuance – replacement of boilers must run alongside measures to decarbonise the electricity grid, and to reduce domestic consumption by insulating older homes.”

For now, the question of how best to manage the UK’s energy transition remains very much open. However, this project, as well as the university’s wider sustainability strategy, goes to show that with the will to do it, and a solid plan to execute, even heritage sites can future-proof their energy usage and save carbon on-site.

Meet the extraordinary community that’s pushing the boundaries of what’s possible. utoronto.ca/news

By Daniel Ovalle Costal

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