I dunno. The curve of solar adoption has looked "great" since 2000. There are lots of troubles remaining like:

- storage over the 24 hour cycle - storage over yearly cycles - how to fix nitrogen for agriculture - how to make carbon-free metals - how to run the chemical industry without fossil fuels

The good news has been the expansion of solar through markets, the diffusion of innovation, competition, and something like Moore's Law. The bad news is we are reaching the saturation point for the grid being able to absorb solar energy in many places and that's going to stop the growth unless those bottlenecks are overcome.