Biogas utilization for electricity production has become a common practice in recent years. Its management is a demanding work that if it is not properly done, a considerable part of the energy will be foregone. With the available data of 5.5 years of operation from the wastewater treatment facility of Iraklio city (120,000 inhabitants), we undertake a technical-economic evaluation. It was concluded that the cost per kiloWatt hour produced is 0.072Euro, while it is purchased at 0.07Euro, a highly subsidized price, since the cost of the primary material for producing 1 kW h is 0.085Euro. It was shown that energy produced is covering 15.9% of the total electricity needs of the facility. This percentage is really low since, according to the analysis pursued in this paper, it could go up to 39% if the recorded problems were successfully solved. The ultimate objective of this paper is to provide a methodology for accessing the electricity produced from other such facilities by tracking and analyzing the problems reported in the examined plant. (c) 2005 Elsevier Ltd. All rights reserved.