Energy transition in BW: How much potential does hydropower have?
Electricity from the sun and wind is the focus of renewable energies. But there are also around 1,600 hydroelectric power plants in BW. Whether this energy source can still be expanded is controversial.
In Baden-Württemberg, more and more electricity is being produced with sun, wind and water. Last year, the share of renewable energies in gross electricity generation was 56.5 percent or 20.9 terawatt hours (TWh). This is estimated by the Center for Solar Energy and Hydrogen Research (ZSW). Almost a quarter of this, or 4.5 TWh, was contributed by hydropower.
Take part now: How are the small streams in Germany?
Iffezheim is home to Germany's largest run-of-river power plant
According to the Ministry of the Environment, there are around 1,500 smaller plants with a capacity of less than one megawatt (MW) in the state, which are mainly privately operated. They are mostly located in the Black Forest and on the Swabian Alb. In addition, there are also dozens of large facilities. Germany's largest run-of-river power plant is located in Iffezheim on the Rhine. The water from the turbines supplies around 250,000 households with climate-friendly electricity every year.
If there is no sun and wind, hydropower will still work
From EnBW's point of view, hydropower plays a "special role" in the energy transition, especially when it comes to pumped storage power plants. In contrast to wind and sun, electricity generation from water can be used in any weather and at any time of day, EnBW said on request. The electricity storage systems are always available and thus ensure stable grids. If there is too little electricity, the water is let out of the tank. If there is too much electricity, the water is pumped up again and held. Another advantage for the energy suppliers is that the systems do not release any CO2 emissions.
However, the Greens and the CDU disagree on the expansion potential of hydropower in the state. While the Green-led Ministry of the Environment considers the possibilities of hydropower - in contrast to those of sun and wind - to be almost exhausted, the coalition partner CDU sees it differently.
Can hydropower be expanded as an energy source?
The Baden-Württemberg Ministry of the Environment sees "hardly any possibilities" to increase the share of hydropower as an energy source. A ministry spokeswoman referred to the SWR to the energy atlas of the Baden-Württemberg State Institute for the Environment (LUBW). There, it was examined whether plants could be expanded or new ones built. The result: The potential is minimal. The reasons given were for example that the water fall height at plants was too low or that the costs for fish protection were too high.
State Fisheries Association and BUND BW against "small" hydropower
At the State Fisheries Association, the analysis falls on open ears. With regard to the small plants, the association criticizes the fact that they often only supply a few households. The ecological effects on flora and fauna in the smallest streams and flowing waters, on the other hand, are considerable, said association president Ingo Kramer to SWR.
The cost-benefit calculation is also very poor for the state association of the BUND. In addition to a disturbed aquatic ecology, all small power plants together generated about as much electricity as a single Rhine power plant, the BUND told SWR.
CDU sees great potential in pumped storage power plants
The energy policy spokesman of the CDU parliamentary group in the Baden-Württemberg state parliament, Raimund Haser, does not accept the argument that the small plants only make a small contribution to the energy transition. He considers their value to be "completely" underestimated, especially with regard to the permanent stable power supply and also flood protection. The plants produce climate-neutrally, without fossil sources. Against the background of the energy shortage and after the shutdown of the nuclear power plants, one must take another look at the country's own electricity production, Haser told SWR.
However, he sees the greatest potential in pumped storage power plants. He therefore thinks it is right that EnBW is expanding its hydroelectric power plant near Forbach in the northern Black Forest into a pumped storage power plant. There is an urgent need to talk about the expansion of further plants.
The Hydroelectric Power Plants Working Group also believes it is possible to increase the share of hydropower in renewable sources. Chairman Martin Renn told SWR that the small plants would have to be technically modernized. Renn is convinced that if the water level and head of many plants were increased, significantly more electricity could be produced. According to its own information, the association represents about 450 of the approximately 1,500 owners of small hydropower plants in the state.
Small plants: "Danger to fish and ecology of waters"
For the State Fisheries Association, the "small" hydropower is also a danger to fish. The operation of the plants in streams or flowing waters could be fatal for salmon, brown trout or grayling, according to Ingo Kramer. For electricity generation, the water in the streams is artificially dammed, mainly by weirs. Fish such as salmon, for example, which are on their way back to their home waters from the Atlantic to spawn, have to overcome the weirs. Although there are now fish ladders, the animal can only migrate upwards there. If the fish wants to "descend" again, it has to go through the turbines at most power plants, where animals can injure themselves or die. Kramer did not want to officially commit to how many animals will be killed.
Expansion of renewable energiesNew hydropower plant in operation in Rheinhausen
In addition, mud and sand accumulate where the water accumulates. The natural flowing waters would be disturbed - to the detriment of flora and fauna. Unfortunately, only a few power plant operators approach the State Fisheries Association to ask how they can improve their own plant ecologically.
Operator: Fisheries and "small" hydropower work together
The Working Group of Small Hydroelectric Power Plants, on the other hand, sees fewer problems with regard to the fish and refers to the experience with anglers on site. They have no objection to small hydropower plants. Such plants have been around for 100 years or more, but fish stocks have only been declining since the 1970s/80s, says Chairman Renn. In his opinion, for example, sewage treatment plants that filter neither hormones nor drugs also harm the fish. His conclusion: fisheries and "small" hydropower work together. Both are users of water.
German government wants to continue to promote small hydropower plants
Small hydroelectric power plants with a capacity of less than 500 kilowatts are currently subsidised under the Renewable Energy Act (EEG). The traffic light government initially wanted to stop funding in 2022. This was met with resistance from the associations of energy companies, including in Baden-Württemberg.