Multi-objective supply chain optimization of renewable energy carrier imports for Europe

The transition toward climate neutrality requires the adoption of renewable energy carriers (RECs). Spatial disconnects between renewable energy production in resource-rich regions and its utilization in resource-deficit regions create the need for supply chains that enable long-distance transport of RECs. To ensure sustainable REC supply chains, we must prioritize affordability, low environmental impact, and supply security. We propose a multi-period, multi-objective, mixed-integer quadratic programming model to design supply chains for importing RECs, including strategic decisions on exporting regions, resource allocation, and infrastructure for production and transportation. We evaluate economic, environmental, and supply-security aspects by minimizing net present cost, greenhouse gas (GHG) emissions, and a supply-security risk approximation measured as a political-risk-weighted Herfindahl–Hirschman index. A European case study shows that, compared with a cost-optimal solution, a supply risk-optimal approach reduces the supply-security risk index by 90% but increases cost by 190%, while a GHG-optimal solution reduces emissions by 12% at an additional cost of 232%. Hence, balancing cost, emissions, and supply-security remains essential for REC import planning. Our findings inform Europe's future REC imports, supporting decision-makers in shaping robust REC partnerships and facilitating Europe's transition to climate neutrality.