What public LiDAR can tell you about a roof
<Assets TBC> LiDAR point cloud of a house with the roof planes highlighted
Public LiDAR surveys cover most of the United States. For a single house, that is enough to read the pitch and direction of each roof plane.
From those two numbers you can tell which planes are worth covering, how many panels fit once vents and setbacks are kept clear, and roughly what they will produce in a year.
Someone still has to check the rafters, the electrical panel and the condition of the roof on site. The difference is that the visit confirms a design instead of starting one. SolarTools will work this way. It is in development.