Comparison of reliability worth analysis methods: data analysis and elimination methods

Electricity supply reliability and interruption costs are nowadays of great interest. Large blackouts around the world have aroused also customers´ interest in the reliability of distribution networks. In addition to this, reliability worth values are widely used in the regulation of distribution companies, and they can offer an excellent tool for focusing the network investments on the most critical areas in the network. In Finland, Helsinki University of Technology and Tampere University of Technology as well as several Finnish distribution network companies worked on a common project concerning the updating of reliability worth values in 2004-2005. This paper presents the analysis methods used in that study, the elimination techniques to remove the strategic or deviating responses from the survey data and correlation studies to depict how the harm depends on the size of the respondent.