The most straightforward path would be if we could bring the cost of solar electric and wind down by another factor of say, three, and then have some miraculous storage solution, so that not only over the 24-hour day but over long periods of time where the wind doesn't blow, you have reliable energy. That's a path. But energy storage is hard. That's not a guaranteed path.
Bill GatesA first-generation fortune is the most likely to be given away, but once a fortune is inherited it's less likely that a very high percentage will go back to society.
Bill Gates