Filed under: Emerging Technologies, Etc.
Rock baloons will store excess wind energy underground for future use
One problem with wind power is that you can never be sure when the wind will be blowing. If you rely on wind power, you've got problems when the weather chooses not to cooperate, which is like... always! One obvious way to collect the excess electricity to be used later would be with big batteries, but there are other ideas regarding the best way to store the power. Take for instance this scheduled power plant in Dallas Center, Iowa. In lieu of storing the power as electricity, the plan for this group is to store the energy in a giant underground "balloon". Well, not exactly a balloon, but a cavern of porous sandstone layers 3,000 feet under the ground. We've never seen balloons made of rock, but if that's what it takes to make green energy available to the masses... well then, rock balloons it is!
[Source: Ecotality via Engadget]
Reader Comments (Page 1 of 1)
Phil L. 4:29PM (10/08/2007)
Interesting idea - but as I read the description, it isn't what I first expected.
The compressed air isn't used to run the turbine - but rather improve the efficiency of a natural gas powered turbine. Note the "Fuel (Natural Gas)" tag in the corner of the diagram.
Any improvement can help. But I'm still waiting for a large-scale energy storage mechanism that makes it possible to efficiently and effectively take energy from intermittent energy sources (wind, solar, etc.), store it with minimal loss, and allow it to be used at will in the future, without the addition of other fuels. It'd also be nice if such a system could fit in my garage!
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Mort 4:51PM (10/08/2007)
This is nice, since they have that geologic feature available nearby. Maybe they could store the energy as geothermal heat in other areas?
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GoodCheer 6:13PM (10/08/2007)
Phil L. There are a few examples of giant batteries used to store electricity. One technology that seems promising is a "flow battery". While I am by no means an expert, I understand that rather than trying to store a lot of energy in a confined volume, they store electricity at low energy density, but use an inexpensive and fluid medium that can be pumped past the business end. This makes it cost effective in applications where system volume is not at a premium. For example:
http://en.wikipedia.org/wiki/Huxley_Hill_Wind_Farm,_Tasmania
Tasmania is (fairly) small, isolated, and windy. 'Back-up' power is produced by diesel generators. I have read that this application has reduced the diesel consumption by about 2/3rds, which I would call a smashing success.
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Monkey 9:39PM (10/08/2007)
Another case of energy conversion gone awry. Take wind to generate rotation to create electricity to drive a shaft to compress air.....
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Dave Smith 10:28PM (10/08/2007)
Tasmania is a net exporter of electricity due to some large hydro there. King Island is small and isolated. Cool battery
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Chris M 1:54AM (10/09/2007)
The efficiency of compressed air power storage drops with increased pressure, due to thermodynamic losses. One way to minimize it is to use a very large low pressure storage tank, so using a very large underground cavern for compressed air storage is a great option - provided they can prevent leaks.
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