Assessment of energy conservation potential and cost in open-pit metal mines: Bottom-up approach integrated energy conservation supply curve and ultimate pit limit

Mitigating energy consumption and greenhouse gas (GHG) emissions in the metal mining industry heavily depends on the employment of energy conservation technologies in each individual metal mine. However, predicting the energy conservation potential and associated cost for a specific mine is difficult, especially considering the interaction between technology employment and open-pit limit variation. Therefore, this study integrates the conventional energy conservation-supply-curve (CSC) approach with the ultimate-pit-limit (UPL) analysis in the estimation of energy conservation potential and cost due to technology application. The results from the case study show that conventional CSC analysis provides overestimated potential with underestimated cost under market-based promotion policy. On the other hand, a target-responsibility-system-based (TRS-based) provides underestimated potential with overestimated cost. Sensitivity analysis shows that energy price has the largest impact on the energy conservation potential and associated cost. The policies that raise energy and carbon prices contribute not only to mitigating energy consumption, but also to reducing associated costs, even though they are accompanied by a reduction in mineral supply. This study suggests that the policy that subsidizes conserved energy should be integrated with a TRS-based policy to mitigate the elimination of energy conservation potential due to expansion of the open-pit limit.