Claim: compressed air in underground rocks could be the next batteries 

Scottish offshore wind project [image credit : urbanrealm.com]

The very fact that these kinds of idea are being put forward is another admission that renewables are chronically intermittent and unreliable as electricity generators. We’re told ‘considerable investment’ would be needed but ignore the fact that, for less cost and complexity, some reliable new gas power stations would be a far more practical plan.

By pumping compressed air into porous rocks deep under the sea floor, scientists think we could effectively store energy for months at a time, says Discover magazine.

With reports about climate change becoming increasingly dire, it’s increasingly important to find an eco-friendly way to not only generate energy, but also store it.

After all, wind turbines and solar power and the like don’t run steadily. So we can’t just stick that extra energy in a bottle to use when the wind dies down and the sun sets.

Only no, that’s almost exactly what a group of Scottish scientists is proposing. Except, in this case, the bottle is a layer of porous rocks deep within the sea bed, and the energy comes from compressed air.

You simply [sic] use your renewable energy source to compress and store the air, and then when you need the energy again you pop the cork, so to speak, and let the escaping air drive a turbine that re-generates the electricity. (Thanks to the extreme pressures down there, the air would stay in place, and not escape on its own.)

The researchers unveiled the details behind the plan, dubbed porous media compressed air energy storage (PM-CAES), in a Nature Energy paper this week. It’s a simple-sounding mix of technologies that could seriously make a dent in a country’s energy production — and mitigate the trends that are pushing the global climate to extremes.

Compressed Air of Superiority

Currently this plan is all theoretical — the paper just runs the numbers on the idea to see if it’s at all practical. But boy, does it seem to be.

The authors specifically looked at how a PM-CAES system could work for the United Kingdom, using the sandstone deep below the waters of the North Sea. They looked at existing geological records to model the terrain, and assumed the air “wells” would be physically near to the energy sources they’d be storing — offshore wind turbines, for example.

According to the researchers, it could really work.

Continued here.
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Nature Energy article: Inter-seasonal compressed-air energy storage using saline aquifers