Renewable energies are an important pillar of sustainable energy policy. But wind and solar energy in particular are dependent on the weather conditions, but are expected to cover around 80 percent of Germany’s energy supply by 2030. Effective storage technology therefore seems essential.
Dark calm
Dark lulls are periods in which neither wind nor solar energy provides sufficient electricity. The reason is changing weather conditions in which there is little wind speed and little solar radiation. According to the Federal Network Agency, “a good half of Germany’s energy needs are covered by wind power and sun” – and the trend is rising. A lack of supply from these renewable energies can have a huge impact on consumers, especially those with dynamic electricity tariffs. For example, on January 20, 2025, the price on the electricity exchange rose “to seven times the 2024 price average. A megawatt hour cost just under 590 euros,” explains the Federal Network Agency.
Lithium-ion batteries
Various technologies are used to counteract these fluctuations due to the dark lulls. To bridge short periods of insufficient power supply, for example to stabilize the grid for a few seconds or a few hours at night, lithium-ion batteries are currently largely used. They can quickly absorb excess electricity and release it again when needed. However, lithium-ion batteries do not represent a long-term solution because lithium is not an endless resource. Therefore, other battery types are being tested. Prof. Dr. Maximilian Fichtner is a German chemist and managing director of the Helmholtz Institute Ulm. In a conversation at his university, he explains that sodium is increasingly being used. But sodium-ion batteries have a lower energy density, which is why more is needed than lithium-ion batteries: “[…] in extreme cases up to three times more. […] Up to three times as many materials, cell casings, fine chemicals, also three times as many ovens, trucks for transport and space,” emphasizes Martin Winter, head of the MEET Battery Research Center at the University of Münster and the Helmholtz Institute Münster, a branch of the Forschungszentrum Jülich, in an interview with the online magazine t3n.
Other technologies
Other technologies are also being researched, including the generation of energy from the targeted fusion of atomic nuclei or energy storage using new batteries or by heating bricks. However, these are not yet fully developed or are rather inefficient. According to the Federal Network Agency, network expansion is a crucial element in maintaining the stability of the system. But consumers can also help by adapting their electricity needs to current generation, for example through the use of smart grids and variable electricity tariffs.
Editorial team finanzen.net
