Same thing as when I was a teenager in the 80's: clean energy. Solar cells are now mainstream and maybe I'll live to see some advance with fusion reactors.
Net-positive fusion reactors still don't solve everything sadly; they're likely to be really costly and because of those economics will only serve really populous energy grids.
One thing I learned from someone wise is to not down-select technologies for a solution (i.e., this is most dangerous when the government down-selects technologies). Something might arise other than solar cells specifically that accomplishes their goal.
I saw a documentary on thorium reactors the other day.. largely forgotten since the start of the Nuclear Age (can't make bombs from it)
Now a bit on the uptake by (still few) scientists. Its a no-no subject because of the vested interests in uranium/plutonium fission and (overly) prestigious fusion projects.
Was not a fan of fission, but this is much safer, more maintainable (liquid salt/thorium mix, runs through pipes), and much less waste ('only' 500yr radioactively dangerous).
And the best thing: Thorium is everywhere. All countries have it, so it would democratize nuclear technologies, be a big help in solving the energy crisis!
