It sounds so simple in principle. but compressing air is very inefficient and storage does not keep energy for long. I like the idea of making the top of the tower simpler. Steve
Saving wind power for later - CNET News: "Its plan calls for sending highly compressed air down the tower and into underground storage, such as caves or depleted gas wells, or through pipelines. The pressurized air can be released when needed to power an electricity generator, even if wind is not spinning the turbine's blades."