I don't think there is any real way to figure lifetime costs of the solar. In order to do that, one would need to subtract worth of the install when I'm done with the house. You never know, but it's possible that added value of the home when sold would cover cost of the install. I've saved $120 + per month on electric bill and also been able to charge the car. Gas costs in the past, while here have always exceeded $200 / month. Then factor in that I sold a toy I was done using and bought solar with proceeds. Any gain on selling this house will be tax free, so I don't think it's a stretch to assume the panels will cost less than 0.