I would expect that centralized power distribution would not be replaced in a fast and efficient manner, even if FF engine would not produce X-Rays and would run on non-flammable fuel.
This is because there is a huge amount of inertia in how things are currently done. I think it will take 5-15 year for decentralized deployments to start in such countries as USA and UK. This is because there will be a lot of political and commercial activity required for it to change:
1)Big companies think big. Small companies will have to be created to think local. The capital will have to be raised.
2)Demand for cheaper electricity will have to happen by voters and political activists. If the prices fall a little by centralized implementation, how long would it take for people to ask for more?
3)Regulations will emerge. Who will they be targeted to? I think those will have to be adjusted for small companies to operate efficiently.
4)Huge demand for the product and human resources will have to be satisfied. This wont happen overnight.
All these things take time, money and effort. Centralized deployment seems much easier in for the beginning, even if its not so efficient. Taking one step at a time will help not to fall, and meet less resistance.