60 MW geothermal power plant in Iceland.

60 MW geothermal power plant in Iceland.
Krafla Geothermal Power Plant by ThinkGeoEnergy CC BY 2.0 via Flickr

The Untapped Heat Beneath Our Feet

Geothermal energy pays off – if you can front the cash needed to find it.

In 1904, Prince Piero Ginori Conti of Larderello, Italy found himself in charge of a boric acid extraction company. One can only assume his life’s greatest ambition was not boric acid extraction, because he quickly repurposed the firm’s resources to begin producing electricity via a reciprocating steam engine.

In 1904, Prince Piero Ginori Conti of Larderello, Italy found himself in charge of a boric acid extraction company. One can only assume his life’s greatest ambition was not boric acid extraction, because he quickly repurposed the firm’s resources to begin producing electricity via a reciprocating steam engine. Using the heat of the Larderello region’s geothermal dry steam fields, Conti was able to produce 10kW of power. Geothermal power was born.

It’s almost a wonder nobody thought of it sooner, since warm geothermal pools have been a source of recreation and relaxation for millennia. Miners, additionally, have long been all too aware of the heat trapped within the earth.

It seems likely that at least one scientist would have adventurously climbed – or stumbled – into a mine before the 20th century, but the lack of results indicates that it can hardly have been an epiphany-inducing moment. As late as 1970, geologists were surprising themselves by discovering that the temperature of the earth 10,000 metres underground is roughly 180 degrees Celsius, or twice what they anticipated. The temperature of the core itself was subject to intense guesswork until last year, when a French research team confidently pegged it at 6,000 degrees. It’s interesting to note that, as far as we can tell, the earth really hasn’t lost much heat since it formed. It almost goes without saying that the reasons for this impressive energy conservation are still a matter for debate.

Drilling for geothermal energy can be like blindly punching nails through a wall, hoping to hit a stud. Except way more expensive.

All this to say then, that if geothermal energy has lagged a little bit behind, we might trace that tardiness back to our fundamental lack of understanding in regards to the earth’s internal properties.

Does this mean that we risk bleeding out all the earth’s heat by punching holes in it for geothermal projects?

Not really.

The challenge is actually finding the heat in the first place. The earth’s crust is not of uniform thickness and we rarely know what’s down there until we look. Regions like Yellowstone or the entirety of Iceland have geothermal activity right at the surface, near the boundary of tectonic plates. Otherwise, drilling for geothermal energy can be like blindly punching nails through a wall, hoping to hit a stud. Except way more expensive.

A BC power company recently spent $30 million drilling wells for geothermal power only to come up empty. If the potential gains were not so high, the risk of such demoralizing failure might be enough to scare off investors for good.

Fortunately, this is not the case. In Alberta, the Borealis Geopower company is looking to draw power from the hot springs near Lakelse Lake. Even though the springs are a dead giveaway for nearby geothermal potential, the company has been studying the area down to the last pebble, with “thousands and thousands of data files” on everything from elevation changes to gas-level measurements. As each exploratory drill runs the power companies something in the neighbourhood of $4-million, it’s easy to understand the urge to proceed with caution.

If successful, Borealis expects to build a 15-megawatt power plant on the site. For a bit of scale, studies done for a 20mW plant in Puga, India estimated that its clean energy will save three million litres of diesel and 28,000 tonnes of CO2 while completely eliminating the local need for kerosene stoves.

Whatever the financial risks, geothermal energy presents enormous possibilities. As we continue to learn how the Earth works under its outer skin there’s no question it will become easier to figure out how to tap into this environmentally-friendly potential.

Oh, and that first geothermal plant over in Larderello, Italy? It’s still producing clean energy.

Stu Campana is an international environmental consultant, with expertise in water, energy and waste management. He is the Water Team Leader with Ecology Ottawa, has a master’s in Environment and Resource Management and writes the A\J Renewable Energy blog. Follow him on Twitter: @StuCampana.