It's location dependent, but it certainly makes more sense at that stage. Roof replacement is a similarly good time to do it. I'm hoping Musk or someone else has the next gen solar roof out before we have to replace a roof.

Undisciplined

That's my point though. It's not really economical to retrofit existing unless you are doing a roof replacement and add installing panels to the scope of the project. New build it should be a no brainer.

Maybe at some point there will be an easy to install solution. Like a bath fitter for solar on roofs. One day install click in and hook up and good to go.

econ

Can Solar Rooftops Power the World?

That's my point though. It's not really economical to retrofit existing unless you are doing a roof replacement and add installing panels to the scope of the project. New build it should be a no brainer. 

Maybe at some point there will be an easy to install solution. Like a bath fitter for solar on roofs. One day install click in and hook up and good to go. 