Looks pretty good to me over 25 years. Not many safe/guaranteed investments that will reliably return 8% these days. And as utility rates will no doubt rise over time, savings in future years will be greater.
Yes the people selling solar systems all factor in aggressive future electricity increases, it's best to also see how it looks with more conservative rate increases. By my calculation in a reply above with the interest free solar loan it's an 8% return over 14.3 years.
Which to me is funny, when the electricity prices will clearly not rise when there is solar energy production from said panels. But might in other times.
