By David Dodge and Scott Rollans
Alberta journalist Derek Leahy is a farm-hand—and passionate about the environment. In the summer of 2018, he launched Rural Routes to Climate Solutions, a grassroots initiative (and podcast) that helps bring green energy ideas and practices to Alberta farms.
Green Energy Futures has co-produced this episode with Rural Routes, based on Leahy’s podcast. He talks to University of Alberta researcher Dr. Jonathan Banks, an expert in geothermal energy. Banks believes that geothermal energy could revolutionize Alberta’s agriculture sector.
“Geothermal broadly refers to the heat of the earth.” Banks explains. “The Earth’s interior is hot. And the deeper you drill down into the Earth, the hotter it gets.”
In other words, if you drill down far enough, you’ll reach heat that you can use up here at the surface. That heat generally gets used in one of two ways. Geothermal refers specifically to the harvesting of high temperatures, usually above 100°C, to generate steam, drive turbines, and generate electricity. Geoexchange uses shallow low-temperature heat of the Earth to heat and cool buildings using heat exchangers.
Currently, Canada has more than 100,000 shallow geoexchange systems, with more added every day.
This is rarely talked about, but Banks says there is also a significant mid-temperature (30-60°C) resource in Alberta that could be a boon to the agricultural sector.
That’s about to change, Banks says. Alberta boasts a very promising geothermal resource. It also has something most other jurisdictions don’t have: thousands of existing, deeply drilled holes left behind by the petroleum industry.
However, there are precisely zero geothermal projects—so far.
“We’ve seen some wells out by Hinton that are well over 180 degrees,” Banks says. As a researcher, Banks has partnered with Calgary’s Epoch Energy to pursue the concept of repurposing some of those Hinton-area wells. The proposed geothermal project could eventually provide electricity and district heating to the community.
Mid-temperature geothermal could be Holy Grail for agriculture
Although only a few wells may be suitable for high-temperature geothermal projects, Banks says many other wells may prove ideal for large-scale geoexchange. “So if you need to run a greenhouse or an agricultural drying operation, or if you have some sort of aquaponics going on and you need 35 to 40 degrees constantly, reliably—boom—most (tens of thousands) wells in Alberta are suitable for retrofitting for those purposes.”
This could spark an agricultural revolution in Alberta, says Banks. “We identified hundreds of geothermal pools that are between 60 and 90 degrees Celsius, and that is really an ideal temperature for running an agricultural operation.”
It doesn’t come cheap—Banks says it might cost $300,000 to repurpose a 3,500-metre-deep oil well. But, that would prove a very sensible investment for a large-scale operation. “You’d have enough heat to run a substantial greenhouse operation,” he observes. “Once you hit that size, your economics look good compared to gas.”
Similarly, a farming cooperative or a municipality could take on such a project—sharing the cost, and then sharing the unlimited, eco-friendly warmth it produces.
Banks is confident this mid-temperature geothermal resource is poised to take off in Alberta, but as we’ve learned in previous stories low-temperature geoexchange is also fast becoming a go-to technology for building net-zero buildings. The Mosaic Centre (also see Geothermal 201) in Edmonton seems to hit a sweet spot at 30,000 sq. feet and the Westmount net-zero church and social housing project is an inspiring super energy efficient, geothermal heated project.
Check out Rural Routes to Climate Solutions, and be sure to subscribe to Leahy’s podcast.
We’ll leave the last word to Derek Leahy: “Happy farming wherever you are in Alberta. And, remember: what’s good for the farm is usually good for the climate.”