Assessing the impact of electricity markets on resilience in the context of capacity expansion: An integrated simulation–optimization approach

Enhancing power system resilience to the growing frequency of high-impact, low-probability (HILP) contingencies is becoming increasingly urgent. As the integration of renewable energy (RE) accelerates global decarbonization efforts, challenges such as resource intermittency, substantial capital investments, and evolving market dynamics complicate the planning and construction of resilient power systems. Despite technological advancements, the lack of a holistic resilience assessment that considers both technical and non-technical dimensions hinders progress toward more integrated energy systems. This study evaluates the impact of electricity market structures on post-disaster system operations, aiming to identify optimal market mechanisms under expanded RE generation capacities. A sequential simulation–optimization approach is used, combining a Modelica-based tool to simulate the frequency of the system with the optimization of post-disaster operations in nine market modes. A multidimensional resilience assessment framework is proposed. Key findings from the modeling results include: (1) Expanded RE generation capacity can destabilize system frequency, but it mitigates energy supply risks during post-disaster periods; (2) Electricity market modes significantly influence the unit cost of purchasing solar energy from prosumers, with real-time markets initially reducing costs, but day-ahead markets becoming more effective as RE capacity increases; and (3) A threshold RE capacity proportion of 13.64% is identified, where resilience performance reaches its peak, shifting the preferable market mode from real-time to day-ahead beyond this point. This study contributes methodologically by proposing an integrated modeling approach and assessment metrics for evaluating system resilience that consider both technical performance and economic costs. Practically, it provides insights for system planners and policymakers on balancing RE expansion with market dynamics to enhance system resilience.