Always working solar lamp – Part 2: right under my nose

Intro A while ago I set out to build a solar lamp that can work all the time, especially in the dark winter months. Using real solar production data and a simple excel model, I was able to figure out combinations of battery and solar cells that would be able to power the LED in a SOLVINDEN lamp through the dark winter months. But in my laziness, i never ended up building it. Until I… Continue reading

Always working solar lamp – Part 1: the data

Intro Everybody knows them: solar garden lamps. They work quite well during summers, when there is a lot of sun, days are long and nights are short. But come winter nights and you barely get anything from them. So i thought, what would it take to make a solar lamp that can always run when it is dark, winter or summer? In fact, this ties into a more general question: how do I size a… Continue reading