Field lessons from a multi-platform solar portfolio

This piece is aimed at engineers who design large commercial solar projects, but the basic idea is worth knowing if you're weighing solar for your own property. Where you put solar panels — on a roof, on the ground, or under a carport — changes the entire engineering problem, not just the equipment involved.

A rooftop system has to work within what the existing building can structurally support, since panels and mounting hardware add weight the roof may not have been designed to carry. Fire codes also require clear pathways around and between panel sections so firefighters can access the roof, which can shrink the usable space and limit how large a rooftop system can be. Ground-mounted systems depend heavily on the soil and site conditions — things like soil strength, groundwater, and drainage determine what kind of foundation is possible, and fire rules require clearing vegetation around the array instead of leaving space on the structure itself. Carports are the most involved of the three, since they're new structures built over parking areas with people and cars underneath, so they have to meet accessibility rules for parking spaces along with structural and fire requirements.

None of this changes the basic appeal of solar, but it explains why cost and design can vary so much depending on where panels go. If you're considering a ground-mount system or carport rather than a rooftop array, expect the site conditions and local codes to play a bigger role in cost and layout than the panels themselves.