SM your argument is based on everything staying as is, Power plants as now, peak demand as now. Maybe some thought has to be put outside of normal. This area dairy farmers are on a staggared start up time, every one used to hit the start button a 4 PM, and constantly, the system failed.
I say everything can be overcome, with some thought.

579,

The problem with maximum demand has been with us from when they first started generating, or building roads etc. Peak demand is driven by human behaviour. People all eat (in or out), shower and watch Tv in the early evening, which is when maximum demand occurs.

If you can find a way to change this, you probably can also cure cancer.