Photo voltaic cells have been used recently which are much cheaper than panels.
The biggest problem with Solar Energy is that it is being torpedoed by Energy Company CEO's and corporate shills. If the U.S. really wanted to, instead of a ridiculous Manhattan Project, the money could be poured into alternative energy sources creating many jobs. The problems associated with Solar Energy could easily be solved. Instead, the U.S. had decided to poison the public with Nuclear facilities which are even more dangerous then the issuing of carbon emissions from coal plants. Nuclear facilities require coal plants to run them on top of everything else.

The only problem with Solar Energy is that the present government is unwilling to consider it in lieu of the present grotesque "clean coal" or "safe Nukes". In short, the lack of decent regulatory commissions which are bullied by corporate lobbyists and the greed of the Energy CEO's spell disaster for global warming and ultimately for the human species.

In short, any problems could be easily solved if there was the will to do it.