At the risk of tooting my own horn, or at least the horn of the company I work for, click here.
But can you tell me if the systems your company produces can power a city of say 75,000 population? What's the re-charge time on an exhausted NiMH battery and does it develope 'power level memory' if discharged too much? What would be the cost of attaching the system to a power transmission or distribution grid? Would a thryristor station be necessary for conversion to AC? Could the stored DC power be successfully stepped-up to match the voltage level of the grid. How about synchronization?
Like I said, intentions are fine, but do we want to invest scads of cash in someone's intention.
Still, I commend you and your endeavours.