Reducing energy consumption by using self-organizing maps to create more personalized electricity use information Teemu Ra ¨sa ¨nen * , Juhani Ruuskanen, Mikko Kolehmainen Research Group of Environmental Informatics, Department of Environmental Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland Received 5 September 2007; received in revised form 17 October 2007; accepted 22 October 2007 Available online 14 February 2008 Abstract Identification of electricity use is one of the key elements to motivate customers to promote activities leading more effi- cient use of energy. Furthermore, electricity use comparisons with other similar customers give more interesting and con- crete point of view to examine own consumption habits. In future, electricity providers and retailers are willing and probably forced by legislation to provide such information by the means of energy conservation and efficiency improve- ment. On the other hand, high number of customers set challenges to handle electricity use data and to create proper com- parison information. In this study we present efficient and highly automated way to create comparison groups based on customers building characteristics. The main advantages of the data-based approach are that customer location is noticed, comparison groups are created using concrete building information, data processing is highly automated and also method is computationally efficient. Additionally, presented method provide tool to target and to create customer specific electric- ity saving guidance. The performance of suggested approach was tested using data set which contained electricity use and building information concerning almost 8000 customers. Ó 2008 Elsevier Ltd. All rights reserved. Keywords: Electricity use; Energy efficiency; Clustering; Self-organizing map; K-means 1. Introduction Increasing concern about global climate change has led to greater interest in energy consumption. It is well known that changes in consumption habits, leading to more efficient use of energy sources, are essential. Recent European Union legislation reflects this concern and more stringent laws concerning efficient use of energy are in the pipeline. This means that energy distributors and retail energy sales companies selling elec- tricity or other types of energy should provide information about past and current consumption, load profiles, customer segmentation, geographical location of customers, comparisons of the consumer’s current energy consumption with consumption for the same period in the previous year in graphical form and comparisons 0306-2619/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.apenergy.2007.10.012 * Corresponding author. Tel.: +358 17 162373; fax: +358 17 163191. E-mail address: teemu.rasanen@uku.fi (T. Ra ¨sa ¨nen). Available online at www.sciencedirect.com Applied Energy 85 (2008) 830–840 www.elsevier.com/locate/apenergy APPLIED ENERGY