Solar eclipse – pumped-storage plants help prevent power failure

Pumped-storage plants guarantee supply security during severe weather changes

The power supply in Germany remained stable during today’s solar eclipse. Aside from conventional power stations, this stability was also owed to our pumped-storage plants. Since, in the course of the energy transition, electricity is generated by growing numbers of photovoltaic systems and declining numbers of conventional power stations, pumped-storage plants are playing an increasingly important role in balancing out temporary weather changes. This is due to their capability of swiftly absorbing and releasing electricity. It is essential that operators can run pumped-storage plants on a profitable basis to ensure that sufficient numbers of such plants will be available in the future. At present, the trend is going in the opposite direction. This is the conclusion drawn by the members of the “Pumped-Storage Plants – Partners in the Energy Transition” platform initiated by the Deutsche Energie-Agentur (dena) – the German Energy Agency.

“The solar eclipse has demonstrated the importance of pumped-storage plants for our future supply security,” says Ulrich Benterbusch, dena's Managing Director. “The Energy Industry Act must be swiftly amended to ensure that the operation of pumped-storage plants becomes more profitable.”

Among other demands, dena’s Pumped-Storage Plants Platform calls for an end to the disadvantages pumped-storage plants face when it comes to grid fees. At present, pumped-storage plants are paying grid fees for the purchase of the electricity they require to pump water. The buyers of the electricity that the plants subsequently feed into the grid are also required to pay - this time for grid usage.

Why are pumped-storage plants vital for our supply security?
Today’s solar eclipse was an exceptional situation as the power provided by Germany’s photovoltaic systems dropped dramatically and rose again in a very short period of time. The rise of photovoltaic power towards the end of the solar eclipse led to a particularly exceptional fluctuation in the power grid since the eclipse ended at noon - the time of maximum sunlight irradiation.

However, even less extreme weather changes, for instance substantial cloud drift, are having a more significant impact on the German power supply system as the percentage of weather-dependent power generation from wind turbine and photovoltaic systems is growing in the course of the energy transition. The resultant fluctuations in power generation have to be offset to prevent power failures.

In the future, instead of conventional large-scale power plants, alternative solutions are required to maintain flexibility in the power grid and offset fluctuations. This also includes expansion of the power grid, adjusting demand to production, adapting renewable energy systems and, in particular, increased use of electricity storage facilities. At present, the only profitable storage capacities with a high degree of efficiency and very short reaction times are pumped-storage plants.

Further information on the important role played by pumped-storage plants in the energy transition and the demands made by the Platform is available at www.pumpspeicher.info.