Primary control provided by large-scale battery energy storage systems or fossil power plants in Germany and related environmental impacts

- An environmental assessment of primary control provision has been conducted.
- Battery energy storage systems (BESS) and coal power plants (CPP) are compared.
- A novel approach for comparison of environmental impacts has been developed.
- Scenarios of CPP operation have been analysed by varying sensitive parameters.
- BESS achieve a better relative environmental performance in most scenarios.

Increasing renewable energy generation influences the reliability of electric power grids. Thus, there is a demand for new technical units providing ancillary services. Non-dispatchable renewable energy sources can be balanced by energy storage devices. By large-scale battery energy storage systems (BESSs) grid efficiency and reliability as well as power quality can be increased. A further characteristic of BESSs is the ability to respond rapidly and precisely to frequency deviations, making them technical ideal candidates for primary control provision (PCP).In this paper environmental impacts of PCP by novel Li-ion BESSs are compared to impacts of PCP by state-of-the-art coal power plants (CPPs) using a Life Cycle Assessment (LCA) approach and considering German control market conditions. The coal power plant stock is characterized by varying properties. Thus, different scenarios of CPP operation are analyzed by varying sensitive parameters like efficiency loss and required must-run capacity. Finally, PCP by BESSs and CPPs are compared in terms of environmental performance. The more must-run electricity generation is attributable to PCP of CPPs, the higher are the environmental impacts of these CPPs. This leads to a better relative environmental performance of BESSs in most scenarios. Contrary, comparative or even better environmental performance of CPPs compared to state-of-the-art BESSs can solely be achieved if power plants without load restrictions for provision of primary control and with extreme low efficiency losses caused by PCP are applied. Consequently, the results of this paper indicate that BESSs are a promising option to reduce environmental impacts of primary control provision.