Wind Farms with Compressed Air Energy Storage

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I’ve added a hot new business plan to the list I’m now featuring. I spoke yesterday with Joe Speace, CEO of “Project Renewable Energy” near Kansas City, whose raising capital for a wind farm that will feature compressed air energy storage (CAES). This looks quite strong.

Storage will be a big deal soon, as the penetration of renewables increases and the intermittence of solar and wind starts to become an issue. I’m hearing about it connected with an increasing number of deals in this space.

And CAES is far more efficient than it sounds. When I first heard about it, I asked, “You’re going to take mechanical energy (a spinning wind turbine), turn it into electrical energy, power a compressor, then, on demand, somehow release the compressed air to turn a turbine and generate electrical energy — again? Doesn’t that sound like a disaster in terms of efficiency?” It turns out that it’s close to 90%!

And what about the huge underground caverns that store the compressed air? Some are man-made, some naturally formed, e.g., those that formerly held natural gas. Don’t they leak at high pressure? Yes, but there is a technology for plugging leaks.

Impressive stuff. And again, that stuff will become increasingly important as time goes by.

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  • Kostas Liapis

    Mr. Speace

    Congratulation for raising $$$ for wind.

    Please let me know if you can help us to raise $$$ for 72MW wind farm.

    Thank you

    Kostas

  • http://gridflexenergy.com Matthew

    I don’t know about 90% efficiency. But I think it’s higher than the 50% given in some sources. If you convert both the electric and gas inputs, as well as output in kWh, into a common term (joules), you get about 63%. However, another way of looking at it is the gain in efficiency on the combustion side by having high-pressure air (compressed by an electricity source presumably low in value at night) feed the turbine rather than compress its own air. The resulting heat rate is very low. So I can see arriving at a figure of about 80% with the latter type of approach. Gridflex Energy, LLC has built its entire business model around developing bulk energy storage (including CAES and its hydraulic brethren, pumped storage) for renewables, and has probably the most sophisticated approach to the integration of wind with bulk storage than anyone in the business.

  • Al

    Have you really thought this through? Have you calculated the enthalpy of the uncompressed air versus the compressed air? Have you determined the efficiency of the entire process?

    And, by the way, have you calculated the temperature of the air exiting the turbine or whatever is going to “harvest” the internal energy of the compressed air/gas? You’ll be amazed!

    I believe the probability of efficiency anywhere near 90% is 0%.

    Please do a rough analysis and post your results. It would be interesting.