[Zathras]

There are a number of people that simply want to show people that it can indeed be done.
There is so much bad information out there that all EVs are oversized golf carts. And of course, it is fairly new tech on the road. We still haven't broken through to the mass production, but the more people that see it can be done (by seeing an EV on the road) the more EVs we will see.
As for usage, I am a bit surprised at those numbers as well.
However, it is quite possible this guy got a great deal on panels, uses less energy than average or his electric costs for grid electricity is a lot higher.