mentor (who got his PhD at Cal Tech, FWIW). He said it was a cool concept but probably still years away. One of the challenges solar farms face is that the solar panels need to be kept immaculately clean if they are to operate at efficient levels necessary to be economically viable. A thin layer of dust is enough to drastically reduce efficiency. It goes without saying that these solar road panels would get incredibly filthy very quickly. Another major challenge is maintenance. A lot of work goes into building and maintaining a solar panel that operates efficiently on farms where they don't face any degrading forces other than the weather. Now you want to run cars all over solar panels and still expect them to run efficiently? We don't have that technology/engineering currently.

In the end, I think it would be awesome if this becomes reality one day, but that will probably take decades, if ever.