Cheaper Energy From Caverns of Compressed Air

An anonymous reader writes "By using the Earth's vast underground caverns to store compressed air generated by wind farms at night, several U.S. municipalities will be 'going green' by using that stored energy to generate daytime electricity on the cheap. Engineers at a National Lab think compressed air stored in underground caverns could cut in half the cost of electricity."

Comments

vast?

[Ydna]

Earth's vast underground caverns? Oh please. If scientists actually tried doing this, it would surely bring about the end of life as we know it. The atmosphere would all be sucked up into these vast caverns leaving nothing but a vast vacuum on the surface. No, thank you!

Re:vast?

[w0mprat]

Your right, such a project would produce unacceptable levels of vacuum emissions into earths atmosphere. But this could be a good thing!: Production of Vacuum tubes and Cathode Ray Tubes in the 20th century used up all the easily available vacuum on earth (mined from the air which contained precious little vacuum! - bringing it down from space is not cost-effective!) humanity had to make do with the transistor and now we have to change to LCD screens since CRTs are no longer profitable to manufacture. But this could change things!

Re:vast?

[srjh]

You'll also need to purify the dirty vacuum that is present in the earth's atmosphere.

I suggest a vacuum cleaner for the task. (ducks)

Re:vast?

[PHPfanboy]

And this is why I have applied for a job at NASA. Think of all the vacuum we could mine from space!!! (Space is also very big but we'll make sure we get mines near to earth, to reduce our transport costs and make it cost effective)

We'll make a fortune selling vacuum to store in caves and then once we've sold to local authorities and energy companies we can sell to homeowners "A Vacuum for Every Yard" and then as the market becomes educated we can crack the enterprise and SMB market with "A Vacuum on every Desktop".

P.S.
I first got the inspiration for this awesome business opportunity idea from the documentary movie "Spaceballs".

Re:How Efficient is It?

[WalksOnDirt]

How Efficient is It?

If you just throw away the heat generated during the compression, which I think is what is done in current large installations, I have read that you can get about 50% efficiency. The fact that natural gas is used in conjunction with the compressed air to regenerate the stored power confuses the issue, which leads to much higher efficiencies sometimes being claimed.

Here they are proposing to capture the compression heat and use it (with an "adiabatic generator"), which should help the efficiency. I'm a bit surprised the energy savings are worth enough to cover the capital costs of tapping such a low grade heat source, especially since this is also excess energy that will also need to be stored for later.

Not really new news?

[inflex]

This has been done on large scales by a couple of power plants in the past.

http://en.wikipedia.org/wiki/Compressed_air_energy_storage

Kubla Khan

[lazyDog86]

In Xanadu did Kubla Khan
a stately pleasure dome decree
where Aleph, the sacred river ran
down to caverns measureless to man...
from memory, apologies to Coleridge

Those words were famously written after an opium-induced hallucination, as was this plan

Flatulence

[riceboy50]

Yeah, I keep a lot of compressed air in my cavern. It's so powerful that sometimes I can't contain it any longer and it escapes. /ducks

Untapped reserves

[KlaymenDK]

Production ... used up all the easily available vacuum on earth (mined from the air which contained precious little vacuum! - bringing it down from space is not cost-effective!)

Oh, come off it. There are still plenty of untapped vacuum sources around.

There's about of cubic foot of the stuff in any PHB cranium, you just need to open the thing and tap it! Granted, you'd need quite a bit of source PHB, but that's easy enough to come by -- and it's renewable.