How a solar cell works

In short: A solar cell converts light directly into electricity. It usually consists of silicon, in which light frees electrons and so creates a voltage.

In more detail: The principle is called the photovoltaic effect. Two differently doped silicon layers form a p-n junction with an electric field that separates the charges.

In detail

• Efficiency: Commercial modules reach about 18 to 23 percent of the incident light.
• Direct current: Solar cells deliver DC. An inverter turns it into AC for the house grid.
• Orientation: South, east and west are good, tilt about 30 degrees. Shading lowers the yield strongly.
• Storage: A battery stores power for the evening (stromspeicher-und-eigenverbrauch).
• Output: Given in kilowatt-peak (kWp), the peak power under standard conditions.