[downquark1]

That is not the entire story. Renewables energy introduces additional grid oscillations which require extra work to control.

There are ways of storing energy but really they aren't all that great. We just don't one want a situation where we have absurd amounts of energy one minute and zero energy the next.

For instance if everyone has solar panels they become obsolete since electricity on the grid would be free whenever the sun shines and when the sun isn't shining the power is expensive again.