Scenario-based DEA assessment of energy-saving technological combinations in aluminum industry

This study deals with technology evaluation by employing the data envelopment analysis (DEA) methodologies from a life-cycle analysis (LCA) perspective. Aluminum production is associated with high electricity consumption. Thus, the environmental pressures of the whole production chain largely rely on the electricity generation process. This is particularly true for China, because coal-fired power generation dominates China’s electricity supply. Many of aluminum plants in China consume electricity which is directly supplied by coal-fired plants. Given these facts, LCA perspective in this study is believed to be of distinctive significance. Therefore, this paper discusses the process requiring high-energy consumption and causing high pollution from the LCA perspective and combines data envelopment analysis with LCA to evaluate and select energy-saving technological routes throughout for the complete supply chain. In total, 16 technological combinations are considered, and three models are established for different sets of efficiency indicators: energy performance indicator, energy performance indicator with undesirable output, and total performance indicator. Moreover, four scenarios with different policy considerations are designed: baseline scenario, subsidy scenario, low-carbon-price scenario, and high-carbon-price scenario. The results show that upon only considering energy input and output at the same price, a power generation mode has the greatest impact on energy consumption. After considering undesirable output, such as pollutant emissions, the technological routes including coal-fired power generation have the worst performance. Considering all inputs and outputs with the same price, the most crucial factor affecting efficiency is cost, followed by anode; subsidies have a low effect. For the four scenarios, two technological routes including a biomass-integrated gasification combined cycle power generation and inert anode rank in the top 50% decision-making units with three efficiency indices. This paper proposes an effective decision-making method for evaluating and selecting energy-saving technology routes for the aluminum industry, which can be easily applied to other sectors with similar characteristics. This provides a generic framework for a profound analysis to promote clean production and environmental sustainability.