Here in Sweden a bunch of offshore wind farm project and even residential PV installations are blocked by the military for unspecified reasons that everyone assumes is that it blocks radar and other signal intelligence.
Even though you can partially work around the issue with better onshore equipment or just placing the stuff on the other side of the interfering equipment it is still a step down from not having any interference in the first place. Especially if you want to keep your listening equipment secret.
That makes sense but my first thoughts were that panels wouldn't be oriented so that the majority of that flat surface was perpendicular to the radar but instead much closer to parallel, and that aviation radar would be higher up than a house roof to avoid ground clutter.
Since it’s all classified o honestly don’t have a clue. But passive radar is also a thing and something that the Swedish defense industry is fairly good at https://en.wikipedia.org/wiki/Passive_radar.
It probably has more to do with the fact that solar that far north is a non-starter. Any PV installed there will actually make AGW and carbon emissions worse, not better. Basically, the amount of carbon emitted due to manufacturing is greater than the carbon savings over the lifetime of the panel in those locations.
Even though you can partially work around the issue with better onshore equipment or just placing the stuff on the other side of the interfering equipment it is still a step down from not having any interference in the first place. Especially if you want to keep your listening equipment secret.