You need to add in: . savings on what you would have spent importing juice from the grid, but didn’t use because you were generating your own . future price rises
The payback then starts to look much more attractive.
I installed 50 kwp of pv using thin film panels a couple of years ago – they had to on a very shallow east/west roof and were almost as effective as polycrystalline on a 35 degree south facing roof over the course of a day – better in low light (cloudy) conditions.
I must admit that the price of installing pv system is still gradually falling, and that’s great. I hope that people will turn to being more environment-friendly…
Oh, I read that you were talking about ….