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The power of the Earth rests just below Michael Coe’s feet.
Coe, a St. Albert gynecologist, is laying plastic pipe on the floor of the Bridal House building on St. Thomas Street, currently under renovation. The pipe, he explains, is part of the office’s geothermal heating system. Hundreds of little plastic braces are stuck all over the concrete floor and the pipe will eventually snake through them, creating a maze of loop-de-loops. Hot glycol in that pipe will heat the floor and building, heat drawn from the Earth itself via a massive underground radiator in the parking lot.
It won’t look like much when it’s done, Coe says. "Geothermal is really just a hole in the ground." But that hole could save him up to $30,000 a year, he estimates, and keep tonnes of greenhouse gases out of the air.
Geothermal power is everywhere. Its advocates say it can slash heating bills and greenhouse gas emissions as well as supply about 10 per cent of Alberta’s electricity, making it one of the most viable alternatives to fossil fuels around.
Yet it is difficult to find in Alberta. Coe’s system is one of just five known in St. Albert and one of a handful in the province. There is not a single commercial geothermal power plant in the country. Alberta’s next big power source may be right under our feet, but we’ll have to get through some big fiscal barriers to dig it up.
Hot from rocks
Geothermal power takes the energy in hot rock and turns it into heat or electricity. People have used it for centuries in the form of hot springs, but it wasn’t until 1904 that someone thought to tap it commercially. Geothermal power now produces 10,000 megawatts of electricity worldwide, according to a 2006 study by the Massachusetts Institute of Technology (MIT), and helps heat over a million North American homes.
Geothermal power comes in two forms, says Leigh Bond, St. Albert resident and chair of the Alberta Geothermal Energy Association: solar and core. The difference is one of depth.
Solar geothermal uses light absorbed by the ground as heat. The ground soaks up about 46 per cent of the energy delivered by the sun. Dig down about nine meters, and you’ll find that it stays seven to 14 C above zero year round, even in the dead of winter.
You tap this heat with a ground-source heat pump, a device that works like a refrigerator. Drill a bunch of holes in the ground about 60 meters deep and drop long tube-loops filled with either water or glycol into them, Bond says. These tubes act as a radiator, sucking about three degrees of heat out of the ground during the winter. A compressor squishes the fluid to raise its temperature to about 100 C and then radiates that heat throughout the house.
The system works in reverse in the summer, Coe says, sucking heat out of the building and storing it in the ground. "It’s like a big thermal battery," he says, and captures summer heat for the winter for when it’s needed. "By the end of September-November, that ground is toasty warm."
Solar geothermal systems are catching on in Alberta, Bond says. "There’s about 2,000 installed in Alberta, and we’ve grown about 40 to 50 per cent per year in the last three years."
Core geothermal systems have not: there are none in Canada, although one has been proposed near Whistler, B.C. These systems use heat from the Earth’s core to make steam and electricity.
Mory Ghomshei, head of the Canadian Geothermal Energy Association and professor of energy resources at the University of B.C., explains that you drill down two to four kilometres to hit either really hot water or rock — about 100 to 200 C — throw down a pipe loop, and use the resulting steam to drive a generator. Since the Earth’s core underlies its entire surface, core geothermal power is theoretically available everywhere, provided you drill deep enough.
Renewable, clean, cheap…
The potential power of this technology is massive, Ghomshei says. B.C. could generate about 5,000 megawatts of electricity if it taps all its geothermal resources, he estimates, or enough to power half the province. Alberta has less potential — 500 to 1,000 megawatts — but that’s still enough to meet 10 per cent of the province’s peak needs, according to the Alberta Electrical System Operator.
Significantly, he continues, this is constant, reliable power. Wind, hydro, and solar are great power sources, but aren’t reliable: the wind stops, the sun sets, and the river runs low. Geothermal is constant since the Earth’s core is always hot, meaning it can provide base load power electrical systems needed for stability.
It’s also very clean. The plants emit almost no carbon dioxide while in operation — about 27.2 kg of carbon per megawatt, according to the MIT study, compared to about 994 kg for coal. Acid rain and particulate emissions are also miniscule; effectively, all that’s coming out of the smokestack is steam.
Ground-source heat pumps are also clean if they get their electricity from renewable sources. The pumps can eliminate the need for natural gas, Bond says, but also raise electricity use by about 30 per cent. In Alberta, that means the pump puts out about as much greenhouse gas as a normal furnace since its power comes from coal. B.C. has more hydropower, according to Ghomshei, so that could mean a 100 per cent cut in your heating emissions. According to Environment Canada, heating buildings accounts for about 10.5 per cent of Canada’s greenhouse emissions.
It can also be cheap. Geothermal power plants require no fuel, Ghomshei notes, meaning you don’t have to spend money mining coal or uranium. Geothermal is also renewable, since the Earth’s core and the sun constantly heat the ground. The Geysers plant in California has been able to run off the same hot patch for 92 years as a result.
Coe says the solar geothermal system he built into his old building down the street eliminated his need for natural gas. The resulting savings means the system will pay for itself within four years. The one in his current building won’t be as good since the building’s less efficient, he says, but should cut his gas use by at least 80 per cent and pay off in five years.
But expensive
Many people turn away from geothermal power due to its up-front cost, says Ghomshei. A typical single-home ground-pump system costs about $20,000 and pays off in 15 years, he says. "People don’t see much incentive to invest in something with a payback of 10 years." Coe says his system cost $80,000 more than a gas furnace.
Most of this money goes into drilling, Ghomshei and Bond say. Big plants might need $10 to $20 million worth of drilling before they can confirm if it’s viable to build a plant, and most junior prospectors can’t afford that. Someone buying a $40,000 ground heat pump might spend half of that drilling the holes for it.
Lack of training is another obstacle, Bond says. There are less than 1,500 people certified to install geothermal heat pumps in Canada, so many owners who want the system can’t find people to build them.
Governments will have to put up more money if they want to see more geothermal power, according to Ghomshei. He suggests either a per-megawatt subsidy for green electricity, such as ones passed in B.C. and Ontario, or subsidies for well exploration.
Coe predicts that solar geothermal power will soon take off as Albertans become more environmentally conscious. "They’re going to request it, and be, in Alberta, able to pay for it."
Geothermal power is just one part of a very big, very green future, Coe says. "Our impact from simply being here is enormous, and we have to take the responsibility."
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