Due to the sun being very low at this time of year, my only sensor can only register when a shadow is not cast over it.
The only way over was to relocate it to the front of the house during the winter, but then I have the problem of a shadow being cast across the sensor at another part of the day.
So, apart from stating the obvious by relocating the sensor on the roof (which would be very difficult in my case), can I use 2 similar sensors so that if one was in the shadow, the other, which would be still in the sun to continue registering the sun hours where applicable.