Similarity measures and comparison methods for residential electricity load profiles

Abstract

The simulation of residential electricity load profiles (ELPs) has always played an important role for designing and evaluating energy systems for buildings or entire neighborhoods. Large-scale measurement data, the counterpart to these synthetic data, are often not available or only available at great expense in terms of time and under consideration of data protection. Therefore, sometimes very detailed and elaborate load profile generators are created, which allow the simulation of different scenarios even without measured data. Simulating electricity load profileson a large scale on the one hand, and as detailed as possible on the other, is subject to several challenges. A particular challenge is the assessment of representativeness and the question of which measures are used to evaluate this. Specifically, which measures indicate whether the curve progression of a synthetic load curve becomes more similar to measured curves and when it does not. Electricity load profiles are highly complex structures that depend on numerous conditions. This paper aims to present an approach that addresses the issue of assessing the similarity or representativeness of electricity load profiles. Emphasis is placed on the comparative measures that are expected to indicate the representativeness or similarity between synthetic and measured electricity load profile data. In the first step, comparative measures used in the literature are gathered as well as classified with respect to their statement on the similarity of electricity load profiles. It is of essence, that similarity in this paper corresponds to the likeness and not the sameness of electricity load profile data. Adding to the measures found in the literature, three further similarity measures are introduced. Using measured electricity load profile data from a case study and synthetic electricity load profile data from three different load profile generators, selected similarity measures are calculated and compared. It is found that in addition to measures of position, central tendency and dispersion, the newly introduced complexity measures may substantiate the expressiveness with respect to the similarity of electricity load profiles. In particular, the complexity measure of the fractal dimension seems to be a potential for further similarity studies.