The earth beneath us has been used for heating and cooling our dwellings since ancient Roman times. Now, geothermal energy is being used for heating and cooling in ways that might seem advanced but actually aren’t much more complicated than they were in 200 BC.
Just in case you weren’t paying attention during those high school science classes, here’s how geothermal works: Geothermal energy is thermal energy generated and stored in the Earth. The temperature of the Earth’s core is more than 4,000°C but the surface of the Earth’s crust ranges from 6° to 11°C here in Ontario, depending on the area and season. Geothermal uses this subterranean temperature to provide heating in the winter and cooling in the summer, using a simple indoor heat exchange system. This system consists of pipes filled with a water-glycol mix and buried under the ground. During winter, these pipes bring heat inside and convert it to warm air. During summer, they deposit heat into the ground and replace it with cool air inside.
Geothermal is considered to be one of the most sustainable heating and cooling methods available because it doesn’t burn fossil fuels, it doesn’t produce carbon dioxide and any reasonable amount of heat taken from the earth by humans is small compared to the overall heat content of the Earth. In fact, the Earth as an internal heat content of 1031 joules, which is about 100 billion times the current energy consumption of the entire world each year.
Dundas resident, Lenore Dickson, has a geothermal system under the ground in the backyard of her home, in an effort to reduce the environmental footprint of her family. The system was installed in 2006 and has run seamlessly, through both the winter and summer months, ever since.
“I love that our house is a comfortable temperature without the use of fossil fuels, the geothermal system uses very little electricity and the air conditioning is silent,” she says. “It may cost a bit more up front but it is so worth it.”
Lenore has quite a large property, so her geothermal system is horizontal, which means that the 3,000 feet of pipe runs side-to-side,across the surface of the ground. It used to be that geothermal systems could only be horizontal, which meant that a large piece of property was needed to install one. Now, vertical systems have made it possible to install geothermal with little to no space. Toronto hostel, Planet Traveler, known as the greenest hostel in North America, actually had 6,200 feet of pipe installed underneath the laneway beside the building.
At this point, most geothermal users are homeowners, like Lenore, that are inspired to seek out installation on their own but many argue that it should be mandated as part of the development of new communities. At this point, nothing has been mandated, but some development companies are taking the initiative to do it anyways.
It was recently announced that a 300-home neighbourhood being developed in north Markham, known as Berczy Glen,will be the first in Canada to connect each house to a geothermal energy system .The neighbourhood, which is a partnership between Mattamy Homes, Enware Energy Corporation and the City of Markham, is set to begin construction in 2020.
It was also announced that the City of Toronto recently approved the design for the Etobicoke Civic Centre, which will include a geothermal system and other renewable energy sources, such as solar and sewer heat recovery, to reduce carbon emissions. When it is completed, this will be the first net-zero community in Toronto, which means that the total amount of energy used will be comparable to the amount of energy produced, but construction isn’t set to start until 2022.
Geothermal systems might not seem that technologically advanced—they’re little more than pipes in the dirt, after all—but these systems bring our heating and cooling needs into harmony with the natural temperatures of the earth in a sustainable way. Whether it’s on a small or large scale, homeowners like Lenore, business owners like Planet Traveler, development companies like Mattamy and municipalities like Markham and Toronto,are using geothermal to lay the groundwork for a more sustainable future.
Last modified: March 6, 2019