In yesterday's MIT Technology Review there's an interview with Jefferson Tester, who claims that geothermal power is a potential game-changer in the energy world.
Technology Review: How much geothermal energy could be harvested?
Jefferson Tester: The figure for the whole world is on the order of 100 million exojoules or quads [a quad is one quadrillion BTUs]. This is the part that would be useable. We now use worldwide just over 400 exojoules per year. So you do the math, and you know you've got a very big source of energy.
How much of that massive resource base could we usefully extract? Imagine that only a fraction of a percent comes out. It's still big. A tenth of a percent is 100,000 quads. You have access to a tremendous amount of stored energy. And assessment studies have shown that this is thousands of times in excess of the amount of energy we consume per-year in the country. The trick is to get it out of the ground economically and efficiently and to do it in an environmentally sustainable manner. That's what a lot of the field efforts have focused on.
The idea is to break up super-hot rock way down in the earth, flood it with water that absorbs the heat, and bring the water back up, in effect mining the heat. Tester says the technology's been successfully demonstrated and we could have commercial-scale plants up and running within 10 to 15 years.
The advantage over other renewables is that geothermal provides steady baseload power:
TR: What are the advantages compared with other renewable sources of energy?
JT: Geothermal has a couple of distinct differences. One, it is very scalable in baseload. Our coal-fired plants produce electricity 24 hours a day, 365 days a year. The nuclear power plants are the same way. Geothermal can meet that, without any need for auxiliary storage or a backup system. Solar would require some sort of storage if you wanted to run it when the sun's not out. And wind can't provide it without any backup at 100 percent reliability, because the typical availability factor of a wind system is about 30 percent or so, whereas the typical availability factor of a geothermal system is about 90 percent or better.
It sounds great, but as always, the proof will be in the pudding.
For more info, see this diary by Devilstower over on dKos. Also, another Kos diarist named Leading Edge Boomer says he's seen a (as yet unpublished) draft of a technical paper Tester's co-written on the subject. "IMHO," he says, "this is A Big Deal."
The top 10 sources for energy
Drill, baby, drill
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JoulesBurn Posted 1:11 am
03 Aug 2006
The typical heat flux towards the earth surface is .06 watts per sq. meter--much smaller than the solar energy flux. To generate 1 MW of power, you would need to collect 100% of the geothermal energy over an area of 6.4 square miles. That's a lot of deep drilling.
Abundant energy does not equal abundant power.
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GRLCowan Posted 2:46 am
03 Aug 2006
--- G. R. L. Cowan, former hydrogen fan
Boron plus pure oxygen: internal combustion without exhaust
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ffletcher Posted 3:16 am
03 Aug 2006
It would seem to me that the cycle of radiant energy associated with the rotation of the earth, day and night, would create heating and cooling which gravity would then order such that the cool would be beneath the warm, provided temperature of water is above 39F
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GRLCowan Posted 5:29 am
03 Aug 2006
--- G. R. L. Cowan, former hydrogen fan
Boron: A Better Energy Carrier than Hydrogen?
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Junkk Male Posted 4:33 pm
03 Aug 2006
When I was a kid I wondered why we couldn't just tip all our waste into volcanoes, so the lava would take it to the earth's core, melt it all down and separate it all back into its basic chemical and ores again. Wouldn't that be neat?
But I'm just wondering about the consequences of mucking about with the balance of flowing (virtue of heat that is proposed to be removed?) magma, which by the numbers seems so vast anything we do will be very small, but may still be significant.
As one who thought it a stretch when some laid the Asian tsunami at the door of global warming, I was nonetheless moved to at least wonder a tad by subsequent theories based on the consequences of climate change on the ocean floors, and even sucking vast volumes of oil out of the ground.
How sure are we that our demands won't divert enough energy from down there to up here to not have a consequence?
I guess after nuclear I'm just worried that in our desire for more sources of energy rather than using less, we tend to rush into things that may cause a few new problems down the line. But then I was the one who wondered what sucking the energy out of the wind at coastlines may do for inland climate balances.
Just asking. I'd love to be reassured.
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sunflower Posted 12:19 am
04 Aug 2006
Deep hot geothermal wells are not cost effective. I have been asked about the prospects of increasing shallow geothermal temperatures with solar concentrators because the low grade heat from the ground is not efficient for generating electricity.
Geothermal energy has a niche for carbon-free energy and is one example why wind is just part of what needs to be done.
Most important is that the US has over-developed energy and more energy is not needed. We could shut down 50% of our energy supply with conservation and efficiency improvements, a cleaner and more cost effective base-load source of energy.
Don't carpool alone.
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tblakeslee Posted 8:17 am
16 Feb 2007
Most of their plants are in geothermal areas but improved drilling thecniques may soon make geothermal economical throughout the world.
http://www.renewableenergyaccess.com/rea/news/story?id=47 ...
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