Electricity-Carbon Collaborative Optimization of Electrolytic Aluminum Load Considering Green Certificate-Carbon Trading and Demand Response

Due to its large capacity and rapid adjustment capability, the electrolytic aluminum load (EAL) possesses significant potential for flexibility and can participate in demand response (DR) to alleviate peak regulation pressures on the power system. Within the frameworks of carbon emissions trading (CET), green-certificate trading (GCT), and renewable portfolio standards (RPS), the electricity-carbon benefits of the EAL acting as a multi-market participant are tightly coupled. Therefore, it is imperative to develop an electricity–carbon collaborative optimization strategy for EALs participating in DR. First, based on the dynamic carbon emission characteristics of EAL, a GCT-CET coupling model is constructed, and the ladder CET cost structure is enhanced to better characterize carbon trading expenses. Then, the production regulation model, regulation benefit model, and DR model are formulated for the EAL. Finally, considering the uncertainty of on-site photovoltaic (PV) generation, a stochastic electricity-carbon optimization model is proposed, incorporating GCT, CET, and DR, with the objective of maximizing the comprehensive net benefits. A real-plant case study demonstrates that the proposed model increases the EAL’s comprehensive net benefit while substantially reducing average energy consumption and total CEs. Sensitivity analyses with respect to the compensation price coefficient, carbon-quota auction ratio, and carbon-quota reduction ratio further verify robustness. Overall, the results indicate that electricity-carbon co-optimization enables EAL participation in DR to deliver both economic and environmental benefits.