Although it is probably a structure. :lol:
Yeah, and the definition of a structure is so vague that all I need to do is mortar two bricks together, and that meets the definition of a structure. :roll:
There is an exception in 690.12 that excludes buildings whose sole purpose is to house equipment for a ground-mount solar array (like a shed for inverters, which would have uncontrolled DC conductors feeding in to them), so logically that would also exclude the structure of the ground-mount solar itself. The framework that mounts a ground-mounted solar array is only built for the purpose of the solar array.
Carports are a gray area. I would expect them to not count as a building for the purposes of the 690.12 article, since it is a free-standing framework instead of what you usually think of as a building, but I have difficulty justifying it objectively with what the NEC gives me. All I need is a statement that buildings need walls to count as a building. The building definition references fire walls as the way that different sections of adjoining units will count as separate buildings, but no mention that walls are required to count as a building in the first place.