seasons In the summer, solar systems produce more energy than in winter since the sun is higher and the days are longer. One interesting point which most people don’t realize is that solar systems don’t like too much heat and will produce around 20% less energy than their peak on a 40-degree day. As a result, your solar system may reach its peak output at any moment throughout the spring or autumn seasons. However, in the summer months because of longer days, overall your system generates more energy units.   Cloudy Solar modules function on cloudy days but generate less power than on bright days.  Under a light cloud, the modules may produce half as much as they would in bright sunlight.   Temperature Surprisingly, the hotter a solar panel gets, the worse it performs. So, even though they may be receiving the same amount of sunlight, a solar system will perform slightly better at 11 a.m. than at 1 p.m. because the panels are hotter at 1 p.m. Shading Solar systems should be positioned as much as possible to prevent shading. Shading slows productivity dramatically unless you have a particular set-up (e.g. micro-inverters). Some shading in the early morning or late afternoon is acceptable, but you don’t want any shade in the panels at midday.