We're honestly almost past that at this point. Solar is devouring the world. Total global electricity production capacity is about 10 TW. China is currently producing 1 TW of panels annually. And the panels are still getting better and the prices are still dropping. We will quickly reach the point where the vast majority of global electricity production is solar, and everything else is a rounding error.

There just isn't going to be any reason to build fusion plants. Maybe in the distant future colonies in the outer solar system and beyond will use them. But for anything inward of Mars, solar is the way to go. Solar+batteries is already, in 2026, the cheapest form of baseload power available. Material limitations are not a problem with modern battery chemistries. Daily swings in power demand will be solved by batteries. And we simply won't have to worry about seasonal power swings. We'll build enough solar panels to meet all our winter needs. We'll build enough to power our cities during the coldest, cloudiest months. And then the rest of they year we'll have super-abundant dirt cheap power.

The future is one of vast energy abundance. We're going to find all sorts of ways to use energy that we've never even dreamed of before - mostly to take advantage of the abundance of dirt cheap energy we'll have during all but the coldest months.

The days the steam engine are numbered. With the exception of remote polar outposts, everything's going solar. It's simply the cheapest most abundant form of energy we've ever discovered. Nothing can match it.