In 2000, renewable energies only contributed around 6% of electricity consumption. Thanks to the EEG in Germany (Renewable Energy Sources Act), that has changed significantly: Electricity generation from wind and waterpower as well as solar energy increased to 244 billion KWh (43%) until 2019. (Source: Agency for Renewable Energies e.V.)
The bigger challenge lies in the sensible storage of energy or an intelligently developed power grid within Europe in order to absorb peaks and energy that is, for example, generated at night but not consumed, in order to be used nevertheless.
What types of energy storage are there?
Pumped storage power plants are a tried and tested mechanical technology. Electric current drives several pumps, carrying water up a mountain. Later, the water flows back down into the valley, driving a generator, which in turn produces electricity and feeds it into the grid. Energy suppliers use this technology to ensure the regular supply of the population.
Sector coupling means to use renewable energies additionally for heating, cooling and transportation in order to get rid of fossil fuels. Important technologies in this context are power-to-gas, power-to-liquid or power-to-heat. In power-to-liquid technology, synthetic fuel is produced with the help of renewable energies. All other terms are explained in the following.
Electrochemical storage systems in the form of batteries have a limited lifespan but can be easily charged and discharged. The buildings are largely self-sufficient thanks to photovoltaic systems on the house or company roof and corresponding storage systems.
With power-to-gas, for example, synthetic energy sources such as hydrogen and methane can also be produced using electricity from renewable energies. This method is intended to enable the medium and long-term storage of large amounts of energy.
In the area of heat storage, there are various options, hot water heat storage for example or geothermal heat storage. With these, small city districts can be supplied with energy for weeks or months, depending on the design. Power-to-heat or other heat coupling systems can thus be operated flexibly.
These topics are the content of the BSc Electrical Engineering course with a focus on Power Engineering and Renewable Energies. Information on our study programme is available here. Information on the storage methods can be found here.