concept of CAES Compressed Air Energy Storage is surprisingly simple, and yet still honouring
the laws of physics. It is based on robust technologies that have been proven
for decades in underground storage of natural gas in salt caverns.
source: google maps, efzn.de
Pumped Hydro Storage: The most efficient way currently available to store energy is to pump water upwards and when needed flowing the water downwards and produce electricty in a turbine.
The lack of surface locations for PHS in the energy revolution can be overcome by putting the storage volume below the surface. The erneo concept works similar to Pumped Hydro Storage, but uses compressed air instead of water.
erneo Compressed Air Energy Storage: Contrary to other CAES concepts the air is pumped between 2 underground storage volumes, preferentially salt caverns. The surface footprint is much lower than in PHS, similar to the surface need for battery storage.
The efficiency is greater than 70 %, close to the efficiency of PHS, whereas in conventional CAES the roundtrip efficieny is only 40 %.