Testing different configuration to find out the most optimal vertical solution for solar street lights : this point is particularly important for solar lighting in the north temperate zone of the earth. The critical period is december and january when the daylight is very poor.
The octogonal design works pretty fine after 3 years experiment in center of France (Mont Saint Vincent). 3 vertical modules of each 80W, and a small panel of 60W on the top. Installed with a 600W LiFePO4 battery and a LED street light of 20W (210 lumens/Watt).
However, in theory the most efficient configuration for temperate zone countries should be the one below which produce an average of 28% more energy for the same quantity of solar panel than an octogonal design or a simple square design.
Daily power generated in winter between november and february by our octogonal solar street light mounted in center of France :
