The definition „photovoltaic“ comes from the Greece-word photon = light, and from the italian professor Volta (physicist), as unit of measure for electrical power in volt.

A solar-home-system uses a photovoltaic module to provide power for lights and small appliances. The system also needs a rechargeable battery, so that power is still available at night and on cloudy days.

Solar-home-systems bring huge benefits to homes in developing countries which are not connected to the main electricity grid.