For what it's worth, Kurzweil's position is that his beloved exponential curves apply perfectly well to renewable and battery technology (price/deployment) so we'll have more than enough energy to solve the problem soon.
I don't know whether there are/aren't any bottlenecks or ceilings that he's not considering, but it would be strange if the exponential curves broke down just before they reached the scale needed to address climate change.
I don't know whether there are/aren't any bottlenecks or ceilings that he's not considering, but it would be strange if the exponential curves broke down just before they reached the scale needed to address climate change.