What is a stand-alone or off-grid PV system?
Stand-alone systems are found where there is no connection to the grid. This occurs, for instance, where a connection to the grid would be too expensive. Examples are light buoys in the sea, street lamps in remote areas, the illumination of motorway signs and the like. Although such niche applications in Central Europe are only used where the connection to the grid would be uneconomical, in many parts of the world they are the only way to supply electricity that makes ecologic and economic sense. Thus billions of people are given the opportunity to carry on working after sunset without depending on expensive fuel or without being poisoned with the waste gases from cheap fuel. Such systems usually work with direct current and battery backup.
