Coal generators don't work this way. It can take 12-36 hours to ramp from a cold start. Natural gas (combined cycle turbines) can throttle up in minutes, which is what pushed coal out of the generation mix (natural gas is a perfect compliment to renewables until battery storage is cost competitive, you have to be able to fill in generation intermittency gaps with little response latency).

Here's a great story [1] from the Tampa Bay Times about what happened when TECO (the local utility) didn't want to power down a coal fired boiler to take the generator out of service to clear slag from the bottom of the boiler (TL;DR several people died a horrible death from the equivalent of flowing magma).

Coal is almost dead, just a bit more of a way to go.

[1] http://www.tampabay.com/projects/2017/investigations/tampa-e...

Coal is dead in Britain, there will be zero generation in the next few years. It was the deregulated energy industry that killed it, starting in the 80's, out-competed on price and flexibility by gas.

I don’t want to sound like I’m a fan of coal, but coal died in the UK before it became uneconomical: the coal miners went on strike for long enough that the government made it a strategic goal to never let striking workers be politically relevant again.

A much better plan is to use an excess of solar energy to power processes that produce ethanol-based fuels and then keep a reserve of those (which by the by, is carbon sequestration at best and neutral at worst).

Coal power plants are awkward and inefficient and require a lot of work just to move the fuel around. There's a reason the world worked hard to develop better fuel technologies as quickly as possible.