Roof-Mount vs. Ground-Mount Solar: How to Actually Decide
Ground-mount systems cost more per watt installed but aren't always the worse choice. Here's the real tradeoff most comparisons skip.
Roof-mount is the default assumption for residential solar, and for good reason: it uses space you're not otherwise using, and it's typically less expensive per watt installed than a ground-mount system, since it doesn't require separate racking and foundation work.
Ground-mount becomes the better option in a few specific situations: a roof that's heavily shaded, oriented poorly (a north-facing primary roof plane, for instance), structurally unable to support the added load without reinforcement, or simply too small for the system size you need. If your roof rules itself out on any of these grounds, the higher per-watt cost of ground-mount often still produces better lifetime economics than forcing a poorly-sited roof system.
Ground-mount systems also allow for optimal tilt and orientation regardless of what your roof happens to be doing, which can meaningfully increase annual production compared to a roof panel stuck at a suboptimal angle.
The tradeoff isn't purely financial: ground-mount uses usable yard space, needs its own trenching for electrical runs back to the house, and in some jurisdictions faces different permitting and setback requirements than rooftop systems.
In practice, we model both options against your specific roof and site during the solar analysis phase whenever ground-mount is a realistic option, so the comparison is based on your actual production numbers rather than a rule of thumb about which is 'usually' better.