Not much.
The IEA forecasts are hilarious:
This is refreshingly realistic for an article on solar.Gielen says solar could supply 10% of the world’s electricity by 2050
Wanna see the derivative of that chart? Barely mentioned in the article is the heavy investment in solar panels by the Chinese, which has pretty much skunked everyone's predictions and is the primary reason why nobody really wants to go on record. Solar development is heavily dependent on Chinese policy and they could lose their appetite at any minute. The whole article is kind of hand-wavey, actually. The other big problem is even at 80 cents a watt, solar is a heavy capital investment... and it doesn't take much back-of-the-napkin math to draw a line between $1400/W 60 years ago and $0.8/W now to recognize that the price has been dropping about an order of magnitude every fifteen years. So if you're going to get it for ten cents on the dollar in fifteen years, and if it's going to take 10 years to amortize... what sort of incentive do you have for buying it now? Especially when subsidies are being cut globally. Also: I'm sure that's just bad proofreading, but that's just bad proofreading.
In Europe, a plan to build a massive solar farm in the Sahara desert...