Modeling the Role of Battery Storage in the Nordic Energy System — A 10-Year Perspective on Renewable Integration and Capacity Expansion

Abstract

The transition to a sustainable energy system is a pressing global challenge, with battery energy storage system (BESS) emerging as a promising solution for enhancing renewable energy integration and grid stability. This thesis examines the integration of BESS into the Nordic energy system between 2023 and 2033, focusing on their role in enhancing renewable energy adoption and grid performance. The study aims to evaluate the potential of BESS investments in addressing variability in renewable generation and optimizing system costs. Utilizing the EMPIRE model, a cost-based energy system optimization tool, the study evaluates investments in BESS and renewable capacities to explore their impact on system overall cost. The analysis reveals a highly uneven adoption of BESS across the region, with Sweden leading due to its diverse renewable energy mix, while other countries such as Norway, Finland, and Denmark rely on alternative flexibility solutions such as hydro storage, gas technologies, and existing interconnections. The results highlight the complex interplay between storage, renewable resources, and existing infrastructure, emphasizing that the path to a sustainable energy system is shaped by unique national circumstances. Although BESS proves effective in mitigating renewable curtailment and supporting grid reliability, its limited uptake in certain countries suggests that broader strategies are equally crucial. The study acknowledges limitations, such as static assumptions for renewable generation and demand, which provide opportunities for further research to refine energy models and explore complementary flexibility options. While the work primarily provides a case study of BESS integration in the Nordic region, it offers a starting point for assessing storage technologies within diverse energy contexts.