Introducing System Utilization Index for Energy Efficiency Evaluation and Labelling

Under EU's 2030 Climate and Energy Policy Framework, the European Commission has designed new labels with current scales ranging from A+++ returned to the original 'A to G' scale. They will enable consumers to choose less energy intensive appliances and reduce electricity consumption throughout Europe. European energy efficiency labels display inter alia the energy conversion efficiency of electrical appliances. However, the total power demands are not included in the current energy labels. To provide a better estimation of the overall system utilization, a new index related to power factor is introduced. The focus of this paper is energy labelling of refrigerators and data from related literature has been gathered to evaluate typical power characteristics regarding refrigerators. Active fundamental power, reactive fundamental power, harmonic distortion power, and power factor have been collected in order to provide a new power factor index. A "Power Factor Index" is presented with an 'A to G' scale. Calculations for active power losses in the network show that a nonlinear load with PF=0.81 leads to 52.4% more power losses than a pure resistive load. Additionally "Quality Factor Index" is proposed to ease the addition of power quality features and the comprehension of future energy efficiency labels.