Study on the coupling of the iron and steel industry with renewable energy for low-carbon production: A case study of matching steel plants with photovoltaic power plants in China

Achieving the Dual Carbon Targets is a core strategy for China's response to climate change. As one of the world's largest carbon dioxide (CO2) emitters, low-carbon transformation of iron and steel industry (ISI) is crucial for reaching these goals. The low-carbon production pathway through the coupling of ISI with photovoltaic power systems is explored in this study. The capacity and carbon emissions of 380 steel plants are investigated, and the annual power generation of 10,345 photovoltaic systems is estimated. SP3G/D matching and EDSAC evaluation models are developed to explore the effects of different electricity substitution rates on low-carbon steel production. Results show that in 2021, China's crude steel output was 873 Mt, emitting approximately 1.626 Gt of CO2. With 100 % electricity substitution, the annual reduction could reach up to 310 Mt, but the actual number of plants suitable for retrofitting is limited by geographic factors. Scenario analysis identifies east coastal steel plants as the most suitable for retrofitting. In the baseline scenario, the steel sector could achieve up to 63.98 Mt of annual reduction, which would decrease to 32.25 Mt if cost optimization is prioritized. This study provides a framework and policy recommendations to facilitate China's ISI low-carbon transformation, with significant theoretical and practical value.