How does sun become electricity?

The sun supplies us with energy in the form of electromagnetic radiation on a daily basis. This radiation can be exploited with the help of the photovoltaic effect. To do so, the semi-conductor material silicon is used, for instance. When a thin silicon disc is exposed to irradiation, electrons are set free and can be used to create electricity. The silver grey silicon discs are known as wafers once the production process is reached. To increase a wafer's yield, a special coating is applied which gives solar cells their distinctive blue or black colouring. A thin lattice consisting of metallic conductive strips is also affixed to ensure that the current can be conducted and used. Once this production stage is completed, wafers then become solar cells. The solar cells are arranged in rows and interconnected in so-called strings. Several strings are placed next to one another to form a photovoltaic module, which is then laminated in the last production stage to make it airtight and waterproof. The module is now ready to convert sunlight into electrical energy.

As photovoltaic modules generate direct current which AC networks cannot transmit, a further component is required for a complete solar power system: a so-called inverter transforms solar direct current into alternating current, which can then either be used directly on-site in the building or fed into the electrical grid.