[mungoman2]

But renewable is already cheaper than fossil fuels. Why don't we see this already?

[coryrc]

Renewable PV is the cheapest way generate electricity during daytime at appropriate latitudes.

Notice several caveats: electricity, not heat; daytime, not nighttime; only for some places on the globe.

Most energy use doesn't use electricity. It's one thing to replace an average-16%-efficient internal combustion engine with electricity and another to replace a 96%-efficient condensing boiler.

[gamblor956]

Solar heating has been a thing for centuries.