Seamus J. Wilson wrote:
I live in Phoenix AZ and I plan to install photocells on roof to help
environment.
My house is 11 years old with original ceramic tile roof. I know
ceramic tiles have very long life and problem is the limited life of
the underlay. Before the tiles are ripped out I would like to know
what the life of the underlay is for the hot desert. Some have said
ten years max. How do I assess the underlay life? Should I have the
underlay
replaced during the photocell install?
Thank you,
Seamus J. Wilson

While Phoenix is a good location for solar power, be advised you will not
generate as much energy as it took to manufacture the things in the first
place. A better environmental solution is to outlaw photovoltaic cells.

In your neighborhood, solar water heating is a plus.