What is geothermal energy? It’s heat is drawn from beneath the earth’s surface and used to warm buildings, power greenhouses, or spin turbines that generate electricity. It’s classified as renewable because the planet keeps producing that heat on its own, without any fuel being burned.
What Is Geothermal Energy, Exactly?
So what is geothermal energy in the simplest terms? Picture the ground beneath your feet getting hotter the deeper you go. A few metres down, temperatures barely shift with the seasons. Several kilometres down, in the right locations, rock and water can reach temperatures well past the boiling point.
That heat comes from two places: leftover warmth from when the earth formed, and the slow radioactive decay of minerals such as uranium and potassium deep in the mantle. Where the crust is thinner, that heat rises closer to the surface, sometimes showing up as hot springs or steam vents.
How Does Geothermal Energy Work?
Once you understand what geothermal energy is, the mechanics behind it are fairly straightforward. Wells are drilled into a hot underground reservoir, and water or steam is brought up to the surface.
From the Ground to the Grid
That steam spins a turbine connected to a generator, producing electricity, or the hot water is piped straight into buildings for heating. Afterwards, the cooled water is pumped back underground to recharge the reservoir, so the same source can be reused for decades rather than depleted.
A typical utility-scale plant might circulate tens of millions of litres of water a day through this loop, quietly, with no combustion involved at any stage.
Enhanced Geothermal Systems
Not every location sits on a convenient natural reservoir. Enhanced geothermal systems, sometimes shortened to EGS, get around that by drilling into hot dry rock often three to five kilometres down then fracturing it slightly so water can be injected, heated, and pumped back up.
It’s a technique borrowed heavily from oil and gas drilling, and it’s one reason engineers now talk about geothermal potential in places that would have been written off a decade ago, including parts of the Canadian Shield once assumed too cold at accessible depths.
What Are the Main Types of Geothermal Power Plants?
Knowing what geothermal energy is also means knowing that not every plant works the same way. There are three recognized designs, and each suits a different kind of underground resource.
Dry Steam Plants
These use steam straight from the reservoir to spin the turbine. They’re the oldest design and the rarest today, since naturally dry steam is hard to find.
Flash Steam Plants
Here, high-pressure hot water is pulled up and allowed to “flash” into steam once pressure drops. This is currently the most common plant type worldwide.
Binary Cycle Plants
Heat from the geothermal water is transferred into a second fluid with a lower boiling point, which vapourises and drives the turbine instead. Because they don’t need extremely high temperatures, binary plants can be built in more places than the other two designs, including parts of Western Canada with moderate underground heat.
What Is Geothermal Energy Used For?
People searching what geothermal energy is usually want a practical answer, not just a science lesson. In our experience covering energy topics, three uses come up again and again.
Electricity Generation
Because it runs day and night regardless of weather, geothermal power is often paired with solar and wind to keep the grid steady when those sources dip.
District Heating and Direct Use
Hot water can be piped directly into homes, greenhouses, and even fish farms, skipping the electricity step entirely. Some northern communities view this as a genuine alternative to diesel heating.
Geothermal Heat Pumps
Even without volcanic activity nearby, the ground a couple of metres down stays around 10°C year-round. Heat pumps exploit that stability, pulling warmth from the soil in winter and pushing indoor heat back into it during summer, cutting heating and cooling costs noticeably compared with conventional furnaces or air conditioners.
Is Geothermal Energy Renewable and Clean?
Yes, with a fair caveat. It’s renewable because the underlying heat source isn’t going away any time soon, and emissions per unit of power are low compared with fossil fuels.
That said, drilling still carries upfront costs and, in rare cases, has been linked to minor induced seismic activity, so it isn’t entirely free of environmental trade-offs. No energy source is perfect, and geothermal is no exception.
How Much Does Geothermal Energy Cost?
Costs vary enormously depending on scale. A residential geothermal heat pump installation typically runs somewhere between CAD $20,000 and $40,000 upfront, though provincial and federal rebate programs can knock a meaningful chunk off that figure, and the system often pays for itself over 10 to 15 years through lower heating bills.
Utility-scale power plants sit at a different order of magnitude entirely, with drilling and exploration alone commonly eating up 80 to 90 percent of total project cost before a single well produces power. That upfront risk, more than the technology itself, is usually what slows projects down.
Where Is Geothermal Energy Used in Canada?
Canadians increasingly ask what is geothermal energy because new projects keep appearing in the news, particularly in Alberta, British Columbia, and Saskatchewan. Alberta hosts the country’s first commercial geothermal power plant, built on an existing oil field, using decades of local drilling know-how to reach hot water at depth.
Saskatchewan has a larger project moving forward in stages toward significant capacity. Provinces including Alberta, B.C., and Nova Scotia have introduced dedicated regulatory frameworks, and federal programs continue funding early-stage exploration, particularly in northern regions currently reliant on diesel. In 2026, the federal government put just under half a million dollars toward building the country’s first national deep geothermal roadmap, a modest sum on paper but a signal that policymakers are finally treating the sector as a long-term priority rather than an afterthought. Development remains modest next to countries like Iceland, but the direction is clearly upward, helped along by drilling expertise borrowed straight from the oil and gas sector.
FAQ
What is geothermal energy used for?
It powers electricity generation, district heating, and geothermal heat pumps that warm and cool homes, even greenhouses and hot springs, benefit from it.
What is geothermal energy, is it renewable or nonrenewable?
It’s renewable, the earth keeps producing this heat naturally, so it never runs dry like fossil fuels do.
Advantages of geothermal energy
It’s reliable, low-emission, and available 24/7, making it a steady, comforting alternative to weather-dependent power sources.
What is geothermal energy for kids?
It’s heat that comes from deep inside our Earth, like a giant natural furnace, that people can use to make electricity or keep homes warm.
What is geothermal energy and how does it work?
It’s heat from underground reservoirs that’s pulled up through wells and turned into steam to spin a turbine and generate power.
How is geothermal energy made?
It forms from the earth’s original heat plus the ongoing radioactive decay of minerals deep in the mantle nature’s own slow-burning engine.
How does geothermal energy generate electricity?
Hot steam or water from underground spins a turbine connected to a generator, turning raw heat into usable power.
How is geothermal energy harvested?
Engineers drill wells into hot underground rock or water, bringing the heat to the surface where it can be captured and put to work.
