4c524e74_y_Storage____Clean_Energy_Wonk__1
[0] Compressed Air Storage (CAES) [2] Gas used is about 40% of the amount used in comparable peaking turbine. First built in 1978. [3] 70% to 80% efficient; $30-$100 per kWh [1] 
Energy stored by compressing air into large underground caverns. Air combined with natural gas on exit and burned in turbine. The gas compensates for the cooling as air decompresses.
Large Scale Electricity Storage. | Clean Energy Wonk
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