In cities, I don't see how light reflection off solar would be worse than the reflection of conventional glass surfaces, which are ubiquitous already and which

In cities, I don't see how light reflection off solar would be worse than the reflection of conventional glass surfaces, which are ubiquitous already and which sometimes cause problems (google "London death ray"). Photovoltaic installations tend to be uniformly oriented, so that concave mirror problems cannot occur. In the countryside, things are different: you have massive installations close to ground level, often at hillside slopes, and if you happen to drive on a road towards one of those at that special time of day/year when the reflection goes straight into oncoming traffic you are left with staying calm and hoping for the best. Happened to me on an unrestricted stretch of Autobahn, slowing down where everybody else is also blinded would be a very, very bad idea. As I said, stay calm and hope for the best. I could really see a case for building codes to get updated to prevent such things (the position of the sun over the course of the year is perfectly predictable) and maybe even a revival of heliostat installations for sites where this can be an issue.