Minimum loads of coal‐fired power plants and the potential suitability for energy storage using the example of Germany.

Summary: Fluctuating residual loads force lignite‐ and hard‐coal‐fired power plants to operate at technical and economical limitations. Energy storage systems (ESS) could resolve the plant‐design restrictions and enlarge the overall bandwidth of operation. Therefore, the electricity during minimum load can be stored and later fed into the grid. For this, the occurrence of minimum loads which could enable the periodic charging of ESS is analyzed at the example of lignite‐ and hard‐coal‐fired power plants in Germany. The durations of the minimum loads show marginal deviations within the considered years, as the median varies between 3 and 4 hours. The median of hard coal is 4 hours and for lignite, between 2 and 3 hours, respectively. In contrast to hard coal, the number of minimum loads of lignite increases slightly from 2016 to 2018. In total, the number and duration of minimum loads of both generation types are aligning within all transmission system areas. This is an indication that lignite power plants are increasingly affected by the merit‐order and are gradually being forced to operate more flexibly. Based on the analysis, a rough estimate of a suitable storage size for the integration of an ESS technology was derived for an exemplary power plant. [ABSTRACT FROM AUTHOR]