[dumb_throw]

That's not what's happening. Coal-fired power stations are being re-activated to cover the shortfall.

You do raise a good point - as electricity is fungible, and the power grid is built, operated, and maintained by a national institution, then how can a particular energy provider promise that their power is more renewable than that from the the others? Otherwise, every time Bulb gets a new customer, we are supposed to believe that they get all the renewable electrons, and the power supplied to the rest of us is just a bit more fossil-fueled.

I do know the answer, and that is that those companies just buy and sell the various "pinky promise" certificates and accreditations that pass for being "renewable" and "carbon-neutral" , and have nothing at all to do with actually boosting the supply of renewables.