Hierarchical aggregation of energy performance indicators in continuous production processes

•Local performance indicators are aggregated to management system indicators.•Performance deviations on site level are allocated to plants or plant sections.•The aggregation method facilitates the verification of energy efficiency improvements.•The method is demonstrated on an industrial use case.•The aggregated indicators fulfill the requirements of ISO 50001:2018. The mitigation of the climate change requires a significant reduction of the fossil energy consumption in all industrial sectors. The implementation of formalized management systems supports the industry to continuously improve the energy performance which is measured using so called “Energy Performance Indicators”. One essential requirement for the evaluation is the correction of these indicators and the corresponding baselines by the influences of external static or dynamic factors, e.g. the ambient conditions, the product spectrum or the plant load. This is in particular difficult for large integrated production sites as e.g. in the chemical industry. In this contribution, an aggregation method is proposed to exploit the analysis of the factors on lower hierarchical layers for the evaluation of the performance of an aggregated domain. Thereby, the resulting aggregated indicator and the corresponding baseline consider all the identified factors from the lower layers, which facilitates the analysis and allocation of possible savings potentials. The concept is applied exemplarily to an integrated chemical production site and the contributions of each plant to the deviation of the energy performance of the site are analyzed. The method facilitates the verification of the improvement of the energy performance as required by ISO 50001:2018 and helps decision makers to prioritize investments in energy efficiency projects. The results can be used for discussions with policy-makers, certification bodies and other stakeholders on energy efficiency targets.