Coal and nuclear both suck at changing output quickly. For a quick ramp up/down, you need hydro or gas generators. Hydro takes only a few minutes to ramp up while most (US) coal plants take more than 12 hours.
There is no excuse for still using coal power.
I've been honing my ability to add things I need to a list on my phone's home page. I've been doing it for 7+ years now. If someone asks 3 years later, how much butter to use for belgian waffles that I made once, I'll know it is the blue colored note, 5th line from top.
If I go to the store, I'll still forget I have the list.