Compressed Air Storage Renewable energy alone is plentiful but problematic because availability is not guaranteed. Storing excess electricity generated by renewable sources during periods of low demand is one way to even-out the peaks and troughs of these power sources. One such storage method involves holding compressed air (e.g. in underground in rock formations). The air can be held at pressures as high as 1,000 and 1,500 pounds per square inch (PSI) and released to turn turbines to generate power when needed. By comparison car tyres are kept at around 30 PSI.