Bottled Wind Could Be as Constant as Coal

[Are_grits_groceries]

Wind power has made incredible inroads into the U.S. energy system thanks to big, efficient machines standing hundreds of feet tall. But the future of wind power may be underground.

In the abandoned mines and sandstones of the Midwest, compressed-air storage ventures are trying to convert the intermittent motions of the air into the kind of steady power that could displace coal.

Compressed-air energy storage plants use compressors to store electricity generated when it’s not needed. The air, pumped into large underground formations, is like a spring that’s been squeezed and when it’s needed, it can deliver a large percentage of the energy that it received.

The first and only such plant in the United States went online in 1991, and though the technology didn’t take off, it did prove that it worked. And now, combining cheap wind energy and compressed-air storage could create a potent new force in the electricity markets.
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The nation’s largest energy storage option right now is pumped hydroelectricity. When excess electricity is present in a system, it can be used to pump water up to a reservoir. Then, when that power is needed, the water is sent through a turbine to generate electricity. The U.S. electric system has 2.5 gigawatts of pumped hydro storage capacity, but most of the good, cheap sites are already occupied, and creating new reservoirs is not environmentally benign.
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The man behind the technology slated to be used in the two Energy Department-backed projects is engineer Michael Nakhamkin, founder of Energy Storage Power Corporation. He designed the only U.S. compressed air storage plant, in McIntosh, Alabama.

That plant was built in the late 1980s by a very small southern utility, the Alabama Electric Cooperative. They had a unique problem, Nakhamkin said, in that their daytime load far exceeded their nighttime load, the opposite of the regular pattern.
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‘Three fourths of the United States has geology suitable for underground air storage. At present, more than a dozen utilities are evaluating sites for CAES application.”

But with low fossil fuel prices and little intermittent renewable energy on the grid, there wasn’t much incentive for utilities to build the plants. The plant saved money for the Alabama Electric Cooperative, but it wasn’t “critical savings” as Nakhamkin put it.
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Read More http://www.wired.com/wiredscience/2010/03/compressed-air-plants/#ixzz0hlyMxXeU

I'm not sure this method is environmentally benign either. However, projects are now being funded.

[liberal N proud]

1. What about the energy used to pump the air into these chambers?

There has to be an energy cost related to compressing the air.

[rfranklin]

2. "Compressed-air energy storage plants use compressors to store electricity generated"

It's a way to "save" excess electric.

[madokie]

3. A kitchen cabinet shop near here used to have a wind turbine

that instead of pumping out electricity he installed a compressor and pumped air, bought a huge tank like what is used to store LPG in and used the wind to supply his cabinet shops many air powered tools. The man has since passed on and the last time I was up there, (not sure if I was on the right road,) I didn't see it, but like I said I may have remembered incorrectly where it was as it had been 25 plus years ago the last time I was there. I remember the man was happy as a lark with his setup as it saved him a shitpot full of cash. His company built some of the best cabinets around too.

[Liberal In Texas]

4. Obviously they use the excess electricity produced by the wind turbines to drive the air compressors

No fossil fuels used so it's very clean.

[liberal N proud]

7. Sounds a better than I perceived

I had this whole ethanol scam in my head where it takes as much or more energy to produce than the yield.

If I understand this correct, the energy generated during low energy use periods would be use to compress air which then in turn can be used to boost power generation during peak periods.

[damyank913]

5. Compressors require a pretty large power input to operate.

I don't see this being efficient enough to be economical.

[madokie]

6. Maybe you need to look a little harder then

maybe even look at it from a different angle :-) :hi: