Geothermal greenhouses are delivering what climate-minded food lovers have long coveted: Fresh, sustainably-grown fruits and vegetables 365 days of the year.

Credit: Abrym / Shutterstock.

October 23, 2025

Just over an hour’s drive from the Icelandic capital of Reykjavík, the greenhouses of Friðheimar farm emit a warm glow that cuts through the dark, cold landscape of a sub-arctic winter. Inside the greenhouses, rows of bright red, juicy tomatoes await their harvest, all thanks to water drawn from a nearby geothermal well that is keeping 2,000 square feet of plants in constant, life-sustaining warmth.

It’s the success of Iceland’s geothermal greenhouses such as at Friðheimar that has inspired the NunatuKavut Community Council (NCC) of southern Labrador to now start thinking about geothermal greenhouses for their communities.

Part of the Canadian province of Newfoundland and Labrador, here frost can arrive by late September and linger until May. The short growing season has traditionally meant that communities have had no choice but to rely on fresh produce transported into them by truck and ferry. These supply chains are vulnerable to climate shocks such as severe flooding and winter storms that can leave roads impassable for days.

The greenhouses of Friðheimar are kept constantly warm thanks to water drawn from a nearby geothermal well, even during bitter Icelandic winters. Credit: Friðheimar.

“Some of our communities have greenhouses, but they’re very tiny,” says Krista Oxford, acting director and manager of the Department of Energy for the NCC, the representative governing body for approximately 6,000 Inuit in south and central Labrador. Those greenhouses that do exist rely on diesel fuel for heating.

Conventional greenhouses use fossil fuels such as diesel to regulate temperature. Because of this, they have earned a reputation as one of the most energy-intensive and costly methods of cultivation. Approximately 65 to 85 percent of the total energy consumed in a greenhouse is used for heating. This is expensive, especially in northern latitudes and extreme climates, where it can account for up to 70 to 85 percent of the total operation cost.

“Diesel use is still a reality for so many remote communities,” says Joe Collier, project manager for the nonprofit Net Zero Atlantic, a team of scientists and researchers that is currently helping the NCC determine the feasibility of using geothermal energy in southern Labrador. Even when compared to natural gas use in a greenhouse, geothermal uses about one-fifth of the amount of fossil fuels, resulting in about 83 percent less in carbon or greenhouse gas emissions, according to Collier.

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To create electricity, large-scale geothermal energy projects often require drilling miles underground to tap into water temperatures high enough that the steam generated can be used to power turbines and create electricity.

Low-grade geothermal energy, on the other hand, as Collier explains, uses warm water sometimes no more than several hundred feet below ground. When diverted through piping systems or heat pumps, this type of system can be used for large or small-scale greenhouse growing in all climates.

It’s this use of geothermal energy that has piqued the interest of the NCC. As Collier notes, it has already been used successfully in Labrador and Newfoundland. About 300 miles south of Happy Valley-Goose Bay, in Corner Brook, Western Memorial Regional Hospital has Canada’s largest ground source geothermal heat pump system. Located roughly 600 feet below the parking lot, the field supplies 100 percent of the hospital’s geothermal heating. This gives the NCC hope that low-grade geothermal energy is viable further north for NunatuKavut communities and their dreams of a commercial grade greenhouse.

Around the world, low-grade thermal greenhouses are proving to be a viable alternative to fossil fuels. In New Mexico, Masson Farms has been using geothermal energy trapped just below the subsurface of the earth to heat its Radium Springs greenhouse since 1987. Relying on two wells that tap into the area’s natural hot springs — one 180 feet deep, and the other 110 feet — the heated water passes through the greenhouse system and is returned to the ground via a closed loop piping system.

“It’s the same process as using natural gas or electricity through a boiler system,” says Mark Salgado, sales and distribution manager for Masson Farms. From a growing standpoint, there’s no difference between using fossil fuels or geothermal energy — either way, plants thrive.

In Rotorua, New Zealand, mud boils and steam hisses through vents in the dirt. For more than 25 years, geothermal energy has been harnessed to keep four greenhouses operated by the Rotorua Lakes Council warm. “Being able to heat our greenhouses during winter means we can grow some varieties year-round,” says the council’s communications manager, Ingrid Tiriani.

Yet, as Brandi Obvintseva, communications director of the advocacy group Geothermal Rising, points out, installation costs are often perceived as an impediment to the more widespread use of geothermal greenhouses. In Canada, for example, small commercial greenhouses under 10,000 square feet typically cost $6 to $10 CAD per square foot. The price goes up the larger the structure.

Depending on size, drilling required and location, capital costs for a geothermal greenhouse in northern and remote communities can, according to some estimates, range from $1 million to $5 million CAD. There are also geographic limitations. “Shallow geothermal energy requires tectonic activity or subterranean heat reservoirs close to the Earth’s surface,” Obvintseva says.

The British Columbia company Greenhouse in the Snow has a solution. It supplies geothermal greenhouse kits, some up to 150 feet in length, for small-scale commercial and backyard use across North America.

With the help of pipes even deeper below the surface and a simple blower system, the earth itself acts as a geothermal blanket that keeps vegetables and fruit warm and toasty even in winter.

“There’s one trench that’s eight to 10 feet long,” explains co-owner Chelsea Klages. “There are a multitude of pipes inside that trench and we’re just using a simple blower system, which is blowing air gently through the pipes back into the greenhouse.” This system, which allows vegetables to grow year-round, costs about $4.00 (CAN) a day, Klages says, making it at least 10 times more cost-efficient than a regular greenhouse.

This fall, Net Zero Atlantic’s preliminary report on the geothermal potential in three NunatuKavut diesel-dependent communities — Black Tickle, Cartwright and Port Hope Simpson — is due. If geothermal technology proves feasible, a commercial-scale greenhouse could be built to service all of the communities, Oxford says.

NunatuKavut means “Our Ancient Land,” and the Inuit of southern Labrador have always survived in harmony with the Earth. By tapping into its ancient heat and water, the land continues to be the key to a food-secure future.

Scrolling photos courtesy of Greenhouse in the Snow.

Jennifer Cole

Jennifer Cole is a freelance writer based in Vancouver, Canada. She writes about everything from sustainable gardening and agriculture to nature and the role climate change is having on our lives and the food we eat.

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