Since the fall of 2017, four wind turbines with a maximum height of up to 246.5 meters have been rising high above the trees of the Swabian-Franconian Forest of Gaildorf near Stuttgart. Four wind turbines that can do much more than just generate renewable energy from the wind sweeping through the trees there. These wind turbines have been placed directly on water reservoirs that serve as energy storage units to compensate for fluctuations in the electricity grid. How that works? “In case of overproduction in the grid, we use the surplus energy to pump water from a newly created reservoir in the valley up into these passive reservoirs,” Johannes Kaltner, the project manager of Natural Power Reservoir Gaildorf, explains.
“When there is a power shortage in the electricity grid, we can drain the water into the valley and generate energy through the turbines.”
The system can be set to either draw power from or feed power into the grid within only 30 seconds. “This helps us use renewable energies much more efficiently and adapt our power plant to current needs.”
Water batteries for short-time power storage
Max Bögl Group calls its combination of upper water reservoirs on the hill and lower water reservoir in the valley a “Water Battery”, which functions both ways due to its reversible pumped-storage hydro power plant and penstocks between the reservoirs. The three turbines in the valley can generate an output of up to 16 megawatts. The power plant’s electrical storage capacity is designed for a total of 70 megawatt hours.
Highest wind turbine in the world
Each wind turbine on the hill generates an output of 3.4 megawatts. The water reservoirs that serve as the foundations for the wind turbine towers add up to 40 meters to the wind turbines’ total height. As a consequence, the wind turbines’ hub height of 178 meters and total height of 246.5 meters make the wind power station in Gaildorf the highest in the world—a world record! Every additional meter of a wind turbine’s hub height improves the annual energy output by 0.5 to 1 percent, which means the world record in Gaildorf was not just an end in itself, but an economic stroke of genius. It goes without saying that interest in the pilot project has been enormous, a fact confirmed by project manager Kaltner who welcomed numerous international guests during the construction phase.
The energy sector: an important pillar of the service portfolio
For Max Bögl Group, investing in innovative energy concepts constitutes an important pillar of their future strategy. With its guiding principle “Innovation is built from ideas”, the family-owned business based in Neumarkt, Germany, is a pioneer for the more efficient use of renewable energies. Site manager Kaltner considers their partnership with Würth an important precondition for the implementation of such large-scale projects. “Würth is a powerful and professional partner that makes sure all materials are always available on site—regardless of where we are.” So Würth is making a small contribution to the energy revolution as well—in the Swabian-Franconian Forest, only a few miles from its headquarters in Künzelsau.