This is really old hat by now. Everybody is aware of the fact that when it is cloudy and there is no wind that you will need other sources. But on balance for the planet as a whole there always is plenty of wind and there always is plenty of sun. We are just not capturing it and we are not transporting it effectively across longer distances.

People used to say that you can't make baseline power with solar and wind. Slowly - and often grudgingly - they've come around and now realize that it isn't about 100% availability, that will always be a mix. The question is simply how much of that mix can be offset by renewables and the answer is 'much more than you originally thought'.

And as the price of solar and wind drops further and further that fraction only increases.

Every KWh that is produced by solar and wind does not need to be generated by fossil.