I give public presentations frequently on the subject of climate change and cleantech and sustainability, and probably the most common question I get at these talks is: Why do you hate our freedoms so much? The answer to that question is that I receive enormous amounts of money from the sinister forces of Big Solar and Big Wind to spread lies about a cleantech-powered world. (It arrives in canvas sacks with dollar signs printed on their sides, like in cartoons, which you have to admit is pretty charming regardless of your politics.) This socialistic cabal is essentially Satan’s handmaiden, hellbent on ending the flawless, stable and exquisitely balanced quality of life delivered to us by fossil fuels (*cough*). But I digress.

Probably the second most common question I get is: What about geothermal? I have to admit I don’t have a quick answer for that one. There is no Big Geothermal. They’re not part of the racket – yet. But it always does get me wondering: What is the deal with geothermal? Is it the jetpack of renewable power, that enticing but forever elusive next big technological thing?

Geothermal energy – the harnessing of the heat trapped beneath the Earth’s surface, either as space heating or as process heat to make electricity using steam turbines – seems like the ultimate no brainer. Wherever you are right this instant, there is abundant energy trapped no more than a few dozen yards under your feet, and in some places there are staggering amounts of it. Why not use it?

We do, of course. But for some reason it’s forever the exception, the striking novelty that never gets copied, industrialized, mainstreamed.

A little while back, I mentioned in passing an amazing building I visited in Germany. It’s a design school in the industrial city of Essen, on the grounds of a long-decommissioned coal mine. The building was designed by SANAA, the Pritzker Prize-winning Japanese architecture firm.

Because the architects at SANAA takes sustainability more seriously than most, they went well beyond standard approaches to use any and all tools available on site to improve the efficiency of their building. In particular, they noticed that the operators of the Zollverein complex around them were pumping water out of the disused coal mines constantly to keep the ground from growing too soft and spongy for the buildings above; the water came to the surface at more than 80 degrees F. By routing that "waste" water through a tight web of pipes in the walls of their building, they managed to handle all of its heating and cooling needs without any insulation or external energy supplies – a brilliant application of geothermal energy.

So, yes, we do use geothermal energy, and in certain rare corners of the Earth, it’s a major energy source. Those rare corners, though, tend to be extreme cases – Iceland, for example, because it is essentially a volcanic peak in the middle of the ocean, uses geothermal for more than 90 percent of space heating and 30 percent of its electricity generation.

This still leaves the question unanswered for those of us who aren’t Icelandic and whose houses weren’t built by Pritzker-winning starchitects. So again: What is the deal with geothermal? Surely an energy source almost as ubiquitous as sunshine and more consistent and reliable than any other renewable – trapped pockets of hot air and water, after all, don’t vary like the wind or vanish in the night like the sun – could be doing much more for us than it currently does. So why doesn’t it?

The research on geothermal’s potential is unequivocal – jawdropping, really. Southern Methodist University’s Geothermal Laboratory recently mapped the available geothermal resources for the whole United States, and found that there was enough readily available geothermal energy to produce 10 times as much electricity as coal currently does. This latent power was all within the first four miles of the Earth’s crust – well within the reach of modern drilling techniques widely employed by oil and gas companies already. And as the report noted, many of the longstanding technical hurdles – needing to be situated on top of a volcano, for example, or drill practically to the center of the Earth – have been overcome by new geothermal technologies that work at lower temperatures and shallower depths.

The data for Canada, that vast landmass I call home, is even more staggering: a recent report by the Geological Survey of Canada found that with just 100 projects, geothermal could replace all of the country’s current electricity supply. Canada could be entirely powered by geothermal. As one of the study’s authors put it, “It is just silly not to take advantage of a heat source like this.”

In China, meanwhile, ambitious research has begun on the design of systems to harness the heat trapped in depleted oil wells. Since, as New Scientist notes, "as much as half the cost of geothermal power plants comes from drilling,” this could be a huge breakthrough for the cost competitiveness of geothermal energy.

So are we finally on the cusp of a global geothermal boom? Could I finally buy that summer home in the Hamptons I’ve had my eye on with checks from Big Geothermal? Alas, as has long been the case with geothermal, it’s too soon to tell. The signs are good, though, that its time in the green-energy spotlight is pretty much now.

To trade tales of the emerging boom in hot air 140 characters at a time, follow me on Twitter: @theturner.

The time is now for Big Geothermal
In North America alone, there is enough energy trapped beneath the Earth's surface to produce 10 times as much electricity as coal currently does.