The Potential of Geothermal Power

EskimoJoe wrote with a link to an AP article about progress in the development of geothermal energy. A Swiss company is competing with another in Australia to be the first to commercially develop a geothermal power plant. The concept is simple to understand: earth's core heat transforms water into steam, which in turn causes a turbine to revolve. The potential, though, is enormous. "Scientists say this geothermal energy, clean, quiet and virtually inexhaustible, could fill the world's annual needs 250,000 times over with nearly zero impact on the climate or the environment. A study released this year by the Massachusetts Institute of Technology said if 40 percent of the heat under the United States could be tapped, it would meet demand 56,000 times over. It said an investment of $800 million to $1 billion could produce more than 100 gigawatts of electricity by 2050, equaling the combined output of all 104 nuclear power plants in the U.S."

Comments

Re:Global Warming?

[Scooter]

I guess we already "make" this heat to power the turbines in power stations(i.e. we transform other types of energy into heat), so I would be inclined to say that using geothermal power would not result in a net increase of heat output on the surface. Unless perhaps, that that now guilt-free and cheap electricity causes everyone to go on a leccy binge for the next 200 years and consumption goes through the roof.

I recently visited Iceland where they use the country's ample supply of superheated steam to produce electricity (and provide hot water and heating). A related question that sprang to mind was "if the rest of the world did this, what would be the effects of letting all that heat out? Would the amount of heat that we would cause to escape from the planet's core be significant? We need a geophysicist to give a proper answer to that - but I'm a suspicious bugger and all this "free" electricity looks too good to be true - you know what they say about free lunches. Essentially, we'd be using the planet like a battery: it's just a question of how long it will last - millions of years? Thousands?

One of the other things that struck me about what the Icelanders are doing, is that they may just have struck their country's equivalent of oil. In the past, they couldn't really export their natural resource - steam goes off quite quickly. Then, they figured out how to make electricity with it, which is a bit easier to store and transport, but not out of the country. Now though, it looks like there may soon be a large world market for hydrogen, if fuel cells and other hydrogen consuming automotive engines take off. Iceland has all the ingredients to produce it - seawater, and abundant electricity. There are a number of problems to overcome in transporting it safely, but I reckon these guys may soon be rolling in it.

The Shell petrol station in Reykjavik already sells hydrogen. It's not clear who to exactly right now, but Shell obviously believes it has a future.

The numbers

[el_flynn]

TFA says the goal of the project is nice, but cost is a big barrier. "A so-called hot rock well three miles deep in the United States would cost $7 million to $8 million, according to the MIT study. The average cost of drilling an oil well in the U.S. in 2004 was $1.44 million, according to the U.S. Energy Information Administration."

Yea, so that's about six times more expensive. But wouldn't the savings be much more in the long run? And more "environmentally friendly"? After all, according to http://www.globalissues.org/Geopolitics/ArmsTrade/ Spending.asp#USMilitarySpending US military spending was over $570 Billion in 2006. So why not spend, oh, say one percent of that figure to go towards coming up with clean energy?