But it could be coming from battery. molten salt, or hydro pumped storage all provided by wind &/or solar.
All of which are more easily, cheaply and cleanly provided sources than coal or gas.
Moreover, … if they have their own battery storage filled by PV solar panels, . it won’t matter when the power lines come down, or transformers blow. Those with that set up will be the only folk to have power when those things inevitably occur.