Sounds correct to me. It sounds like they're hoping the compressive heating effects will be dispersed through a large enough volume to be negligible. Whereas the expansive cooling will be concentrated at the point of exit.
The article, and the comments here, are missing an important fact that really helps clarify how these compressed-air energy storage systems work:
These systems use the compressed air as input into a natural gas turbine. You can think of the underground storage as a giant intercooler that stores the output of the first (compressor) half of a natural gas turbine, and then feeds that compressed air into the second (combustion) half.
8 comments
[ 2.5 ms ] story [ 27.3 ms ] threadAs far as I understand they need to heat up the turbine as air (a gas) cools down upon (adiabatic) expansion.
And while accumulating / compressing air in ground lacunae, pumping it into the storage, we are just heating up the ground.
Am I right in my understanding of the process thermodynamic ?
Umm, does this seem as pointless to everyone everyone else as me?
These systems use the compressed air as input into a natural gas turbine. You can think of the underground storage as a giant intercooler that stores the output of the first (compressor) half of a natural gas turbine, and then feeds that compressed air into the second (combustion) half.
See a good explanation here: http://energystorage.org/compressed-air-energy-storage-caes