Huntorf CAES Plant with SSS Clutches

Pumped Air Storage

Compressed air energy storage, also known as pumped air storage or CAES, is a process largely equivalent to a pumped hydro power plant, but instead of pumping water from a lower to an upper tank in periods of excess electric power a CAES plant compresses and stores ambient air at high pressure in underground cavities. 

The process uses excess grid electricity in periods of low demand to power a motor/generator coupled to a compressor that pressurises and stores the air.

During peak times when electricity is require, the compressed air is mixed with natural gas and combusted in a gas turbine coupled to the motor/generator for electric power production.  

The SSS clutches allow the use of a single motor/generator for both the compression and generation, which achieves reduced plant costs and foot print, flexibility and the ability of using the generator as a synchronous condenser.