Compressed air energy storage (CAES) is considered to be an important component of a renewable power grid, because it could store surplus power from wind turbines and solar panels on a large scale. However, in its present form, the technology suffers from large energy losses and depends on natural gas to operate.
A look at the 4,000 year long history of compressed air makes clear that this is not unavoidable. Although our ancestors were dependent on less energy efficient technology, they used compressed air in more intelligent configurations that had fewer energy conversion losses and were independent of fossil fuels.
These historical systems hold the key to the design of a low-tech, low-cost, robust, sustainable and relatively energy efficient energy storage medium. The compressed air economy could be the practical and realistic alternative to the hydrogen or all-electric utopias.