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Cheaper Energy From Caverns of Compressed Air

Posted by samzenpus on from the fine-until-the-earth-burps dept.

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."

5 of 114 comments (clear)

  1. Re:How Efficient is It? by tirerim · · Score: 2, Informative

    I think they're mainly suggesting that it would be more efficient than storing the same energy in ordinary chemical batteries, which is the current method for storing energy from natural sources for times of higher demand (or lower production, in the case of solar). Presumably their calculations are based on minimizing the inefficiencies for both batteries and compressed air.

  2. Re:How Efficient is It? by Free+the+Cowards · · Score: 2, Informative

    What happens if the wind that should be generating electricity for the compressors takes the day off and chooses to make an unfashionably late arrival?

    You draw power from the grid, which you'll still be connected to.

    --
    If you mod me Overrated, you are admitting that you have no penis.
  3. Re:How Efficient is It? by WalksOnDirt · · Score: 4, Informative

    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.

    --
    a,e,i,o,u and sometimes w and y (at be if of up cwm by)
  4. Not really new news? by inflex · · Score: 4, Informative

    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

  5. Re:Why air? by dbIII · · Score: 2, Informative

    would be like using gravity for energy. If you find a way, let me know!

    Easy:

    1/ Lift musical instrument high into the air.

    2/ Let go.

    3/ Voila - energy from gravity!