Linear programming-based optimization of renewable energy systems for island decarbonization: The case of Borkum, Germany

Islands face unique challenges in achieving decarbonized energy systems due to their geographic isolation, reliance on imported fossil fuels, and limited infrastructure. Renewable energy sources such as wind and solar represent viable alternatives, but their variability and spatial constraints difficult reliable system design. A systematic approach is required to align local demand, renewable generation, and storage capacity in a cost-effective way.

This study applies a linear programming optimization framework to determine the optimal configuration of distributed energy resources for the island of Borkum (Germany). The model integrates multiple technologies, including photovoltaic systems, wind turbines, lithium-ion batteries, hydrogen storage, and electric vehicle charging infrastructure. Techno-economic input data such as capital and operational costs, resource availability, and load profiles were used to simulate ten scenarios, each reflecting different technology mixes and investment assumptions.

The baseline scenario shows high dependence on mainland imports to cover annual electricity demand. Scenarios with expanded photovoltaic and wind capacity significantly reduce import requirements, while the addition of battery storage enhances temporal alignment between renewable production and demand. However, storage deployment is only economically viable under reduced cost assumptions. The most effective configuration, combining solar, wind, and storage, achieves substantial reductions in imported energy while maintaining a balanced cost-performance profile. The analysis highlights the importance of diversified technology portfolios and cost-efficient storage solutions for advancing local energy autonomy.

The optimization framework demonstrates strong potential as a decision-support tool for island energy planners. By quantifying trade-offs between cost, energy independence, and system reliability, it provides a structured basis for designing decarbonization pathways tailored to insular contexts. The findings support evidence-based planning for Borkum (Germany) and offer replicable insights for other islands pursuing the transition toward renewable and sustainable energy systems.

The decarbonization of island energy systems is a key objective aligned with the European 2050 long-term climate strategy, which aims for a climate-neutral economy by 2050. This strategy envisions an economy with net-zero greenhouse gas emissions, requiring all sectors — power, industry, mobility, buildings, agriculture, and forestry — to play a role in achieving full decarbonization. In this context, optimizing the energy infrastructure of islands is essential to achieve sustainable and cost-effective decarbonization. Islands present unique challenges due to their geographic isolation, dependence on fossil fuels, and limited energy storage capacity. Efficiently sizing Distributed Energy Resources (DER) and Hybrid Energy Storage (HES) systems through optimization models ensures a balanced integration of renewable sources while minimizing costs and space constraints. By leveraging advanced optimization techniques, this study contributes to the design of an efficient, resilient, and fully decarbonized energy system for islands. The demonstration pilot will be the island of Borkum, in Germany.