I had no power or WiFi at my property when my house and shop was built. I had 4 cameras, all with batteries, cellular modems (built-in) and solar panels. Two of them were Vosker cameras, the other two Spypoint. The Spypoint cameras didn't have solar cells attached so I bought a battery pack/solar charger combo, which worked much better than the Vosker's with the small solar cells only. For the most part, the cameras worked, but they did require some maintenance. Vosker and Spypoint have plans where you pay monthly, depending on the number of photos. The downside is more photos = more battery use.
Generally, the solar would keep up with the usage, but there were times where I had to go out and take the cameras down and charge the batteries manually.
The web sites for both of these looked like they were the same with different branding so I suspect there's one vendor behind that part of it. I'd do it again but you won't get anything like live video or frequent pictures like you can with an AC powered camera and WiFi.
One big challenge is that you need a wide enough angle lens to get a decent view of things, but that also means you won't see a lot of detail.
I'm happy to go into more detail if you'd like - just let me know.
Here's an example - this is a photo of the foundation work (house in foreground, shop in background) on my property. This particular one is from a Vosker V150. mounted on a tree, about 15' off the ground.
