They take a day or more to start or stop. When running they're still not exactly nimble (which is why we have peaking plants) but their response time is an hour

They take a day or more to start or stop. When running they're still not exactly nimble (which is why we have peaking plants) but their response time is an hour or two, not a day. Even old plants ramp at 1%+ of maximum power per minute giving one hour as a very achievable 40%-to-100% ramp up. Newer designs are 5-10x as fast. Not arguing against renewables here but this 1+ day response time figure gets quoted a lot. (eg. my father-in-law uses it and I've always thought it was sketchy, your post just pushed me over the edge to go look it up. ;) Source: Graph on page 10 of https://usea.org/sites/default/files/092014_Increasing%20the%20flexibility%20of%20coal-fired%20power%20plants_ccc242.pdf https://usea.org/sites/default/files/092014_Increasing%20the...