So far, looks like a lot of hype. The numbers thrown out at this point are largely speculation. The article didn't say anything about the energy required to compress the air in the first place. Perhaps a compressor using electricity from a coal fired power plant? While there are some intriguing possibilities, I'm not going to get excited until one is built and tested and we get some hard data to work with, in addition to considering the entire picture of energy inputs and outputs for the net effect on economy and environmental impact. I sincerely hope they can deliver on their promises, but I'm not ready to jump on the bandwagon yet.