This study presents a methodology to quantify the economic impact of condenser fouling on the performance of thermoelectric power plants. Various contributing factors are investigated, including fouling rate, plant load, cooling water inlet temperature and condenser cleaning. Analyses of condenser performance and power output are conducted for a representative 550 MW coal fired power plant. Results indicate that costs arising from additional fuel requirements and production losses associated with condenser fouling are in the range of 0.4-2.2 Million (USD 2009). Furthermore, this study shows that including the cost of revenue losses during a cleaning event can be a significant factor in determining the optimal number of cleanings that are performed throughout the operational year. (C) 2012 Elsevier Ltd. All rights reserved.