Balancing of Intermittent Renewable Power Generation by Demand Response and Thermal Energy Storage

Abstract

Balancing of intermittent power generation from renewable energy (RE) is one of the central challenges within the system transformation towards a more sustainable supply. This talk addresses the potential role of flexible electric loads and power-controlled operation of combined heat and power (CHP) plants in meeting increasing balancing needs in Germany. It relies on an enhancement and application of the cross-sectoral REMix model, which is designed for the assessment of energy supply scenarios based on a system representation in high spatial and temporal resolution. The analysis is composed of three fundamental parts. The first part is dedicated to the quantification of theoretical potentials for demand response (DR) and CHP in Europe. In the second part, the linear optimization model within REMix is extended by DR and the heating sector. In the third part, REMix is applied to assess the future energy supply in Germany. Least-cost dimensioning and operation of DR capacities, as well as heat supply systems are evaluated for different scenarios for the year 2050. According to the REMix results, the application of DR is mostly limited to short time peak shaving of the residual load. This implies that its focus is on the provision of power, not energy. In contrast, power-controlled heat supply has proven to be an effective measure to increase RE integration. It is achieved by a modified operation pattern of CHP and heat pumps enabled by thermal energy storage on the one hand, and utilization of surplus power for heating purposes on the other. The model application reveals that DR and power-controlled CHP operation are not competing but complementary measures in the realization of higher RE integration and lower back-up capacity demand. It can be concluded that both are important elements in a future German energy system mainly relying on renewable sources.