While it's true that coal, nuclear, and gas plants are harder to shut down and startup, you neglected to mention that they have the HUGE advantage that they CAN be shut down or started up whenever needed, in any weather, at any time of day.  THAT is not true of wind farms or solar.<br><br>One of the biggest problems with wind and solar power today is that both are HIGHLY variable. This is made worse by the fact that their variance is often at odds with demand. That is, their output is often low just when demand is high.  For instance, on cold, dark winter's night, solar power produces zero, yet that may be one of the highest periods of demand.