I really love the story of technology. Unintended consequences (eg the telephone). Also, how applications from one field affect another (eg precision boring for cannon and artillery was fairly important to the development of pistons that made the steam engine possible).

Of course, many of these consequences aren't foreseen. Go look at sci-fi from the 60s and you'll see flat screens hanging on the wall. This of course happened but flat screens were one of the critical developments for laptops and, more importantly, modern smartphones.

Battery tech is another interesting one. Battery improvements were initially spurred by laptops and then cellphones. A somewhat unforeseen consequence beyond smartphones is that battery tech (along with smartphones) are largely responsible for the development of consumer-level drones.

Electric vehicles are another obvious offshoot.

So one of the big problems with most forms of renewable energy are that they aren't constant. Wind isn't constant. Sunshine obviously isn't (even beyond the day/night cycle). Hydro has ben the one big success story here and is responsible for some of the cheapest electricity in the world where it's suitable.

I feel like the world is one big battery technological advance from a fairly monumental and far-reaching change. Batteries I think are the real missing link in renewable energy (IMHO).

The nice thing about solar in particular is that in a lot of places in the world it's a good option because it doesn't require a lot of expensive infrastructure (ie power lines). Communities can put solar panels near them. I foresee this as being a hugely positive change and I'm happy to see it.