Guesstimate the build cost + total solar input per year. Get instant payback number.
Use LIDAR to establish some sort of canonical clothes size format? Not just S, M, L, XL that only works for your region. Maybe you don't even need LIDAR, but I'd love personalised clothing.
If it's cheaper than thermal cameras - perhaps some use for lifeguards, especially in night?
You could prototype the solar calculator yourself with any modern mobile device in a trivial amount of time.
For video games maybe but I'd always try to avoid looking at those, even if LiDARs are eye safe it's not fun staring at them.
Alternately, a cheap way to produce amazingly accurate video game maps of your neighborhood.
[1] https://gis.stackexchange.com/questions/142443/what-are-lida...
Much cheaper cameras may be fine for that though...