Maybe I missed this, but I have not seen mention as to the ease or difficulty in shutting down or starting up PV and wind generation capacity. For my own PV system, a simple switch turns it off from the grid, and vice versa. I have passed wind farms with inactive turbines. It would seem offhand that PV and wind can be started up or shut down incrementally as needed to allay the need in many situations to speed up or slow down the big coal fired steam turbine grid power to meet demand, as well as a need to fire up or shut supplemental gas turbines. Smart management at the production location of PV and wind may greatly reduce the the off cited issue of too much or too little PV and/or wind energy.