You cant really store electricity or not efficiently anyway. That kinda ruins the whole idea doesnt it.
The point of storing anything is to be able to retrieve it whenever you want. Electricity can be accessed from nearly anywhere. Also, flywheels are pretty efficient at storing energy. Remember, electricity itself is not being used as a currency; the currency will be floating pegged to the price of electricity.
I have heard that the US defaulted on bonds in '71 although a quick Google search yielded nothing. see this: http://www.zerohedge.com/contributed/2013-10-14/us-has-repeatedly-defaulted
Cost of electricity by source. 1. Natural gas 2. Hydro 3. Coal 4. Nuclear 5. Solar 6. Wind https://en.m.wikipedia.org/wiki/Cost_of_electricity_by_source
uhhhhh.....Did you just try to redefine free-market? http://www.investopedia.com/terms/f/freemarket.asp
Now, I mean that if the free-market price goes out of range, it buys and sells electricity futures, modifies capital and reserve requirements, buys and sells Treasury bonds, etc, to inflate or deflate the money supply so the price goes back in range.
I am related to someone big in the energy biz. I will refer to him rather than wikipedia. nuclear is the cheapest. natural gas prices are variable. happy holidays.