Due to the weather, the power generation from wind and photovoltaics is volatile. So-called flexibility technologies are necessary to balance the ensuing fluctuations. To achieve this end, there are several sound possibilities: From flexibly dispatchable power plants, to storage systems or the balancing of power demand and power feed-in (demand-side management). The challenge is to identify the technologies that combine stability, sustainability, cost efficiency and social acceptability. A Working Group of the Academies’ Project ESYS has developed a special calculation model enabling the comparison of around 130 different constellations. The position paper “Flexibility concepts for the German power supply in 2050” sums up the most important results, the details of which can be found in a comprehensive analysis.
The calculations show: There are numerous possibilities how the energy system could be designed, all at comparable power generation costs. Due to the continuing price erosion, wind power and photovoltaic plants will become the most important power generation technologies. However, in the long term, there is virtually no getting around flexible gas power plants. “They will increasingly be operated with biogas, hydrogen or synthetic methane”, explains Prof. Dirk Uwe Sauer (RWTH Aachen, co-chair of the ESYS Working Group). “New power plants should therefore be engineered with variable firing, enabling the gas sector to successively switch from natural gas to fuels producing less carbon emissions.” This would also be a way of reliably bridging periods of up to three weeks with little wind and solar radiation.