I think we all know the practical and physical limitations to the
Solar Roads concept, but it still raised a few million dollars, anyway.
There are lots of impractical projects out there that may lead to breakthroughs or improvements in current technology. I think the Tesla Tower is one of those projects. Will it solve the world's problems? Absolutely not. But, if you are going to contribute to a wild idea that has little practical use, this is one that is actually very cool:
https://www.indiegogo.com/projects/let-s-build-a-planetary-energy-transmitter