Honestly this is actually kind of smart. The snow/freezing rain won't stick to them, and you get less surface area on the roof for such a building so may as well make use of the walls.
If I had a big property with enough room for a real solar setup I would put all my panels vertical tbh. Do east, south, and west facing arrays. Maybe tilt the south one slightly. Either way for a good part of the year the ground is covered in snow and the reflection off it from the sun will actually go to the panels. Not sure how much that really helps but it's something.
I have a 400w array on my shed but they are a lot of work to keep clear, and the first freezing rain of the year puts them out of commission till mid April when it gets hot enough for it to melt on it's own. The ice is not clear, it turns into a snowy/icy cake and you can't get that crap off. Even on the car it's hard to take off and you really have to scrape down hard, but don't want to be doing that on solar panels.
I want to experiment with nichrome wire or something to see if whatever energy I have stored in the batteries would be enough to clear at least two of the panels when we do get freezing rain, then at least in winter I would have SOME capacity. Last winter was my first with solar and I ended up having to go turn off the inverter. I was producing about 5-10w through the snow. It was enough to trickle charge the battery but not more than that.
I want to experiment with thermal collectors one of these days actually. The evacuated tube ones are expensive, but DIY ones with double pane glass with the pipes inside an insulated box probably won't be that expensive to make. They are more maintenance though. Was reading up on glycol based water loops as I was thinking of doing my garage slab and you basically need to flush the whole system and change the glycol once a year or it starts to go acidic and it will start to eat through various components like metal pipe fittings, pump seals, etc. With pex I guess you could risk it and go with just water, but it will still cause damage if it freezes, and of course be out of commission for the year as the pump won't be able to run anymore. Where the pipe enters the box it will also break the box itself or the pipe will break.