Coal and gas unburnt because of solar and wind generation is still energy stored. The rate at which you consume/burn it is less constant and if renewables deliv

Coal and gas unburnt because of solar and wind generation is still energy stored. The rate at which you consume/burn it is less constant and if renewables deliver eg. 30% of power on average over a year, you need 30% less burnable stuff, which is a win. No need for brownouts, especially in winter when solar is low already and fossil plants would already take most of the load.