Now this bug really should only effect SSP but it seems to effect SMP so now the good news its probably not a calculation bug but rather a rendering bug. I tested sound on and off as some bugs are brought on by sound effects even though their is no sound on Solar panels I wanted to make sure.
This game really kills large uses of solar panels even more if your running SMP Server with large community projects and outposts.
Pictures:
Daytime:
Night:
For people with large amounts of solar panels could you please check time and night and hit f3 and let us know here if your also experiencing these issues.