Getting to the point where the amount of energy it will require to get the panels out of Mars' gravity will be less than the energy delivered will take a long time. And what are you going to do when something breaks down?
As it stands, we have not yet built a factory using exclusively robots. I'm sure that this would have very useful applications on Earth, as well as on Mars, if you were interested in tackling it :).
Then we could have an entire electrical power source for human habitation or machine experiments.