by Anders Alexander
No. But, maybe.
Now for the long answer.
Solar panels cover the roof they are installed over, blocking most water and sunlight. For composite shingle roofs this can greatly reduce weathering on portions of the roof.
The issue is that the entire roof is not covered. Even for the roof section that the panels are on, there is still boarder space that the panels do not cover and that doesn’t allow for full coverage. If a roof gets to the end of its life, but the area under the panel is still good then you still have to replace the full roof.
Theoretically on a composite shingle roof you can cover or just replace the shingles on the boarder around the panels, but that is not the best approach to ensure proper water sealing. Roofing companies will probably not provide this service.
If a homeowner has a few planes of the roof they want to install solar on they can see if its feasible to just re-roof that part to save on roofing cost. Roofing companies are more willing to complete this type of work.
A non-habitable structure, like a carport or a shed, has different rules from installing on a home so you can cover the full roof space. If you completed a project like this correctly then the full roof can be covered and the roof has the opportunity to last longer than usual. The key to this approach is that you have to install the rail and panels to extend 12 inches over the edge of the roof on each end so the panels take up more surface area than the roof itself. Every bit of the roof has to be covered to make it work.
Another choice is to install a ground mount, they can be up on a pole, or lower on the ground as a long row. The property should be at least ¼ acre before considering a ground mount as they take up a lot of space.
Context is the key here. If done correctly, solar can extend the life of a roof.