Optimization of Low-Carbon Transition Pathways for Power Systems Considering Renewable Energy Output Uncertainty

Driven by carbon neutrality targets, the intermittency and variability of wind and solar power introduce significant uncertainties into power system planning and operation, directly affecting transition costs, investment structures, and system reliability. In this paper, we develop an integrated optimisation model for power systems that couples long-term capacity planning with hour-level operational simulation, with a particular focus on characterising renewable energy output uncertainty. Sixteen fluctuation scenarios are designed, covering both shortfalls and surpluses in wind and solar power, to systematically assess the impacts of varying fluctuation intensities, durations, and intervals on system transition pathways. The findings reveal that: (1) short-term extreme fluctuations in wind and solar output have a limited impact on total system costs, indicating that a high proportion of renewable energy systems can maintain strong resilience given adequate energy storage configuration and enhanced system flexibility; (2) scenarios involving simultaneous reductions in both wind and solar power have the most significant impact on costs, highlighting the need to guard against compound fluctuation risks; and (3) longer fluctuation intervals enable system costs to be mitigated through cross-period dispatching, underscoring the critical role of temporal flexibility in addressing uncertainty.