The idea behind CAES is simple enough: CAES facilities purchase inexpensive off-peak power and use it to compress air into underground salt or limestone caverns. During peak-time, compressed air is drawn from the cavern to drive the turbine.
So why is that, to date, there are only two CAES facilities in operation worldwide (one in Germany and one in the US)? Traditionally, the problem with CAES systems is that they suffer from poor thermal efficiency and that they are geographically constrained, given that they can only be sited where limestone or salt caverns exist.
But SustainX Energy Storage Solutions say it has come up with a way to address the former issue, using an isothermal, rather than abdiatic (i.e. does not exchange heat with its surroundings) approach to gas cycling.
Rather than compressing and expanding the air in turbocompressors and turbines, in which the process is inherently adiabatic, the SustainX system instead compresses and expands the gas within hydraulic cylinders (accumulators and intensifiers), which allows for controlled heat transfer with the ambient surroundings during compression and expansion. Using this approach, SustainX has demonstrated thermal efficiencies greater than 90% for both compression and expansion.
While compressed air energy storage has yet to catch on, its application for solar and wind energy storage suggests that the novel concept may become more mainstream before the decade is out. Wind Energy Update speaks to SustainX energy Solutions’ vice president and co-founder, Dax Kepshire, to learn more.
To read more and interview visit here
Source : Wind Energy updates…