... or maybe not OT. Except I'm not really intending to fit any...
It occurs to me that in winter the sun runs across an arc of the horizon of 140 degrees or so (ICBA to find out exactly what) and so at all times if it's above the horizon, and there's no cloud, it's shining on the front of a panel.
But in summer the sun rises and set further north. It's enough that at this time of year the evening sun gets into the windows on the north of our house - which it never does in summer. Does this mean that near dawn and dusk it's "behind" a panel?
Andy