Reply #19: Not enough power.

[GliderGuider]

I found a reference that current solar panels put out about 150 kWh per square meter per year. That figure was for Sydney, Australia, which means that most people will get less than that. Compare that to how much power an electric car needs: 0.4 kWh per mile. That means that with a year of charging off a square meter panel, you'll get 375 miles of driving - about one mile per day.

Technology will improve solar panel efficiency to some extent, and we will build some ultra-light EVs which will use less power than that, but realistically solar flux is too low density to be an effective solution for general transportation.