Oct 14 2010

Geothermal Energy Running Out?

The following article by Nanna Árnadóttir originally appeared on Iceland Review‘s website on the 9th of Október 2010.

About week ago I was faffing about on a whale watching boat—ironically docked across from a whaling boat—for the premier of a short environmental film made by Icelandic legend Ómar Ragnarsson.

For those of you who don’t know who Ómar Ragnarsson is, he’s sort of been everything you can think of: writer, journalist, comedian, TV personality, politician and most importantly now, Iceland’s most prominent environmentalist.

This man is Icelandic nature’s greatest warrior. He has protested, spoken openly about the damage aluminum smelters have done to our countryside and is the most vocal person in Iceland right now about the future of geothermal energy.

I managed to have a conversation with him about it (a shining moment in my life, actually) and he blew my mind.

This is going to sound ignorant—I have mentioned I’m bad at being Icelandic, right?—but I was under the impression that geothermal energy was renewable, which isn’t exactly true because it isn’t endless.

Or so Ómar told me. It’s clean energy, yes. Geothermal power is a reliable, cost effective and environmentally friendly way to harness energy and it is sustainable—provided you actually make an effort to sustain it—but it isn’t endless.

Geothermal energy is power extracted from heat stored in the earth. This heat comes from the original formation of the planet when radioactive minerals began to decay as a result of volcanic activity and from solar energy absorbed at the earth’s surface.

Geothermal energy can’t be harnessed just anywhere, because there aren’t hot-spots (where the earth is warm enough) everywhere in the world, but thanks to the fact that Iceland is abound with volcanoes and straddles two tectonic plates we have quite a few.

Here’s the catch: These hot-spots can go cold. If you harness the energy for long enough, in large enough quantities, without giving the earth time enough to replenish its heat you can suck that baby dry.

“And then what?” I cried at Ómar as he continued to blow my mind with his mad nature knowledge. Then you might have to wait say a 100 or so years so for the resource to replenish itself again.

A hundred years? That’s a long time, right? It sounds like a long time for a plant to stand around disused.

Regardless of how much Ómar’s word meant, even I must be a responsible journalist and look further afield to confirm this information.

So on Thursday I tracked down a geologist at the University of Iceland who specializes in geothermal heating, a man by the name of Stefán Arnórsson.

I asked him about how long it would take for a geothermal plant running on full capacity to deplete its geothermal well. Ómar was right on the money; Stefán said his calculations estimated it would take about 50 years or so in those conditions.

So then I asked if Ómar’s estimate of it taking a 100 years for the well to replenish was right too. Stefán said—and these are his exact words: “If you use energy at this capacity and it runs out in 50 years it won’t replenish itself again in 50 years, or in one century or even two centuries, it could take a 1,000 years before that geothermal system becomes a resource again.”

One thousand years!

So there it is. This is not an endless source of energy. By its definition geothermal energy is considered “officially” as a renewable source because any projected heat extraction is small compared the Earth’s overall heat content.

But in localized sites there is only so much heat you can tap into unless you draw just enough that you don’t use more than the well can naturally reproduce.

We don’t know for sure that localized geothermal well depletion will come to pass in Iceland—but it’s scary to think about.

And with all the recent madness—rightful madness—around the Magma Energy deal, the battle to protect and preserve Iceland’s nature and resources is becoming more troubling.

I haven’t traveled around Iceland as much as I should have and I like it that Ómar and environmentalists like him are out there, fighting for the treasure troves of Icelandic landscapes that I don’t see but, thanks to their hard work, I might get a chance to enjoy in the future.

Nanna Árnadóttir – nanna.arnadottir@gmail.com