Flexibility concepts for the German power supply in 2050. Ensuring stability in the age of renewable energies
So-called flexibility technologies are necessary to balance the fluctuations naturally inherent to power generation from wind and photovoltaics. The various viable options include flexibly dispatchable power plants as well as storage systems or the balancing of power demand and power feed-in (demand-side management). The challenge is to identify the options combining stability, sustainability, cost efficiency and social acceptability.
A working group of the Academies’ Project „Energy Systems of the Future“ (ESYS) has developed a special model enabling the comparison of 130 different constellations. The position paper published by acatech, the National Academy of Sciences Leopoldina and the Union of the German Academies of Sciences and Humanities summarises the main findings and presents design options for energy policies.
The results include:
- Practically no technology is without alternatives. There is always a replacement possible at reasonable costs – provided that the right course is set early on and that misallocations are avoided.
- However, gas power plants engineered with variable gas firing constitute the stabilising backbone of any energy system, ensuring supply security even during several weeks of low wind and solar radiation.
- A flexible consumption- and storage control in the household- as well as the industrial sector (demand-side management) is the most cost-efficient means of balancing short-term power fluctuations.
- Long-term storage systems are only viable if carbon emissions are reduced by more than 80 per cent. Otherwise, it is more cost-efficient to use excess power for the heating sector and curtail any remaining generation peaks.