A small solar power installation consists of at least three components, namely a solar panel, a storage battery and a charging regulator. The charging regulator limits the final charging voltage and also protects against reverse current flow.If you were thinking that nothing new has appeared in Elektor Electronics in the last ten years regarding solar power technology, this article is the proof!In a self-contained solar power installation that can provide electrical energy even when the weather is bad or it’s dark outside, an energy reservoir in the form of a lead-acid battery is indispensable. In order to prevent the battery from being discharged via the solar panel when the terminal voltage of the panel drops below the actual level of the battery voltage, reversecurrent protection is necessary. In its most rudimentary form, such a ‘solar current valve’ is just a simple diode. A Schottky diode, which has a low forward voltage drop, is normally used to minimise losses.