This paper presents a calculation system to evaluate the energy efficiency in the production in general and at the process level more specifically. Its focus lies on the evaluation of the efficiency of the use of electric energy in the manufacturing industry. The basic target is a comparability of the energy efficiency across products through derivation of significant key figures. The basis of a significant evaluation and overarching comparability of the energy efficiency as well as the basis of the derivation of possible saving potentials is the relative energy efficiency (REE). It is determined by the quotient of minimal energy demand and actually measured consumption and requires that the actually measured energy consumption refers to an independent basis of comparison. The step-by-step development of the calculation system is based on the detailed analysis of all influential factors of the energy consumption. The, in this context, developed Least Energy Demand Method enables the determination of energy minima with different bases of comparison as reference values to evaluate the energy efficiency of single parts production.

This paper presents a calculation system for evaluating the energy efficiency at machine, plant, location, company, and sector level based on the process specific minimum energy demand. The goal is a comparability of the energy efficiency across machines, plants, locations, companies, and sectors through definition of significant key figures. The basis of the derivation of possible saving potentials is the relative energy efficiency (REE). [7] It is determined by the quotient of minimal energy demand and actually measured consumption and requires that the actually measured energy consumption refers to an independent basis of comparison. The step-by-step development of the calculation system, structured in levels, is based on the detailed analysis of all the influential factors of the energy consumption with the help of cause and effect diagrams to calculate the minimally necessary energy demands for the manufacturing process. Furthermore, the described bottom-up approach delivers, ensuing from the process oriented level of perspective, the step-by-step conception of the calculation method. The REE of a level of perspective is calculated on the basis of the REE value of the previous production level as well as according weighting factors. On the basis of the calculation, as well as subsequent measurements within the company, optimization potentials [10] can be clearly described and can lead back to their roots. These optimization potentials are based on exemplary trials presented for a chosen manufacturing chain of the electronics production area.

This paper presents a calculation system for evaluating the energy efficiency of a product regarding its production. In order to evaluate the energy efficiency of the manufacturing of a product value-adding processes as well as auxiliary processes are taken into account. Furthermore, the energy consumption of the periphery, in total is included. Since the total value-added chain of a product usually is not located at only one company, the energy efficiency of the manufacturing of the bought-in parts must also be included. In a last step, the plant specific energy efficiency at the product level based on all plants that produce the observed product can be determined. The basic target is a comparability of the energy efficiency across products by derivation of significant KPI’s. The basis to derive possible saving potentials is he relative energy efficiency (REE), which is the quotient of the minimal energy demand and actually measured consumption. For this, it is required that the actually measured energy consumption is based on an independent basis of comparison. This is assured by the stepped least energy demand method, for a product, based on the process-related perspective level of the bottom-up approach.