Actually 25 years is a pretty good match between roof and panel lifetimes.<p>It doesn&#x27;t matter who lives in the house, or for how long, for payback costs. Solar panels are no different from the rest of the roof in that department. When you sell the house, its value is estimated from the age of the fixtures, and that all comes out in the price.<p>But I&#x27;m with you on the central-solar issue. Its got to be vastly more efficient to create a planned installation, than to slap solar on every roof in the neighborhood.