Yes I subscribe to the everything happens slower than you think until it starts happening faster than you thought possible view of (at least some types) of change.
We're near a tipping point, so I expect substantial acceleration over the next decade, but rebuilding whole power systems (and transport systems) world wide isn't a short term proposition. Plus there will be some work to do putting in the system management aspects of this. Voltage management will become an interesting issue to be managed without much synchronous plant providing reactive support, frequency management will be more interesting with substantially less plant inertia on the system. All do-able, but it's going to require some work. And I'm sure some regulatory changes will be needed as penetration heads towards and past 30%.
Plus there is a fair amount of sunk cost fossil fuel plant globally that won't be retiring quickly.
It intrigues me that when we need to be getting close to 100% renewables by mid century our rate of progress is roughly on target for that, if we go fairly hard from here and if storage economics, grid interconnection management/build and system operations improves reasonably quickly over the next ten years. Solar economics I am taking as a given.
