What are three examples of renewable resources

FAQ on renewable energies in general

Renewable energy is energy from sustainable sources such as hydropower, wind energy, solar energy, biomass and geothermal energy. In contrast to the fossil fuels crude oil, natural gas, hard coal and lignite as well as uranium ore, these energy sources are not used up.

Bioenergy: Bioenergy is extremely diverse. Solid, liquid and gaseous biomass can be used to produce heat, electricity and fuels. Vegetable and animal waste is used as well as renewable raw materials, e.g. energy crops or wood. In Germany, bioenergy is currently most important for heating - but biomass is also used for power generation and as a biofuel.


Solar energy: Both heat and electricity can be obtained from solar radiation. Photovoltaic modules on the roof or in open spaces convert sunlight into electrical energy with the help of semiconductors such as silicon. With solar collectors, in which liquid circulates, heat is obtained for heating and hot water preparation as well as for air conditioning. A third technology makes it possible to generate electricity, process heat and cold by concentrating and amplifying the sun's rays: In solar thermal power plants, the sunlight is bundled with reflectors and directed onto a carrier liquid, which then evaporates. A generator or a heating and cooling machine can then be operated with the steam.


Wind energy: The use of wind as drive energy has a long tradition. Windmills were used to grind grain or as a saw and oil mill. Modern wind turbines generate electricity from the power of the wind. They use the lift that the wind generates as it flows past the rotor blades.


Hydropower: Even in ancient Egypt and the Roman Empire, water power was used to drive machines such as flour mills. In the Middle Ages, water mills were used for sawmills and paper mills in Europe. Electricity has been generated from hydropower since the end of the 19th century. Today, hydropower is a mature technology and, after traditional biomass use, the most widely used renewable energy source worldwide.


Geothermal energy: Geothermal energy is the use of geothermal energy to generate electricity, heating and cooling energy. The temperatures in the interior of the earth warm the upper layers of the earth and underground water reservoirs. This energy is tapped with the help of boreholes. When using geothermal energy up to a depth of 400 meters (“close to the surface”), a heat probe in combination with a heat pump uses the different temperature levels between the ground and the ambient air. In the deeper layers, hot water and steam are used to generate electricity and for district heating networks.