If you look up at the roofs of the E&I building on the Emden campus, you'll see a photovoltaic system. Photo comes from the Greek word for "light", Phos, and the word voltaik comes from Alessandro Volta, a famous Italian electricity researcher. So photovoltaics roughly means "electricity from light." And that's exactly what a photovoltaic system, or solar power system, does - it generates electricity from light. Just as a wind current moves air particles, an electric current transports charges. In the case of solar cells, these charges are actually firmly bound to the atoms of the solar cell and are therefore immobile. However, if sufficient energy is added to the atoms, for example in the form of light or heat, some charges can detach from the atoms and be transported away. An electric current is generated. In this way, the solar cell converts the sun's radiant energy into electrical energy. In addition to solar power systems, there are also solar heating systems, which convert the light of the sun into heat, for example for hot water for showering or heating.
Good to know:
Sunlight, wind and plants are among the renewable energy sources. "Renewable" because plants grow back, and wind and sunlight are available on Earth in virtually unlimited supply. Renewable energy sources are environmentally friendly, whereas oil and coal-fired power plants, for example, are non-renewable power generators because their fuel, such as gas, oil or coal, is only available in limited quantities on Earth.
The solar power system you can see on the roof is a project of the Regenerative (or Renewable) Energy Laboratory. The plant can supply about ten households with electricity over the year. There is also a solar boat on campus called the "Sunderbird." The solar-powered boat, which can fit one person driving, can travel at speeds of up to 30 kilometers per hour and has already participated in competitions in Monaco, the Netherlands and Germany. "Sunderbird" is a project of the FabLab (FabrikationsLabor), where students can implement their own ideas.