Solar is also unique in that it is both affordable and practical to deploy locally.

Part of the difficulty in estimating growth is that a significant chunk of installed supply is not a "power station" that is easily counted and measured.

Residential solar is a few kw here, a few there. But it adds up quickly to mw and gw.

And yes, this results in a larger variable demand on the grid. Which makes planning harder. But it's cheap enough for any established business with a roof to install. It's cheap enough for residential. And from decision to power flowing can be measured in months not years.