The world's largest cold (cryogenic) energy storage plant is about to come online as a test bed. The idea is for it to store the energy from wind and solar for use later to even out the peaks and troughs.
It is actually not much more than a modified gas plant and they have been around for almost one hundred years. The big difference is that instead of taking off liquid oxygen (LOX -186 ºC) and liquid nitrogen (LIN -196 ºC) it stops at -194 ºC and they remain. The pressurised liquid is then stored in giant flasks for later use.
When the liquid is let back to the open air it expands very rapidly by an order of 700:1 and this pressure can be used to drive a turbine.
The test is only on the 5MW, scale but even that will provide power to 5,000 places for about three hours. The hope is to scale up to 200MW.
One to keep an eye on.