You misunderstand. The construction and maintenance cost of solar panels in general will go down with time. We will get better and better at making more and more efficient panels. The idea behind the subsidies is to develop the technology to the point that it doesn't need them anymore. The phenomenal progress of solar is undeniable. I think anybody that thinks it's a waste of time has convinced themselves of such because of political reasons.
Cutting off the subsidies until not needed anymore? What about NOW. We have PROVEN technology in many other forms of energy production and available to support our country for many lifetimes.
Spain went belly-up when it dived into this senseless episode of subsidies of renewables. Why do we need to repeat its mistakes?
When was the last time anybody cut a welfare check out from a recipient?