EFFECTIVE CAPACITY AS A MANAGEMENT AND ASSESSMENT TOOL FOR A HYDRO-POWER STATION

Abstract

Management of large power stations in a developing nation like Nigeria is difficult due to inadequate technical expertise and funding available to plant managers, engineers and technicians. Often the effectiveness of the plants is couched in mystery as measures of “reliability”, “maintainability” and in aggregate terms “availability”, which are not easily understood by funding authorities. A more practical measure that can be easily interpreted by even the most technically uninformed, for the purpose of decision making is a new metric (Effective Capacity) that precisely represents the actual ability of the plant to power loads. Effective Capacity is determined for each unit by calculating its total energy output over a specified time and averaging it to determine the effective performance of the plant in that period. This method was applied quarterly in each year to the five turbo-alternators in the Jebba Hydropower Station (JHEPS) in Nigeria using the data collected over a total period of eleven years (2004 - 2014). The computed effective capacity for each turbo-alternator was studied by plotting the quarterly effective capacity, the frequency polygon of the quarterly effective capacity and their cumulative density functions over the said period. The results showed that the machines were working less than the rated values for most part of the period which implies under-utilization and wastage of substantial revenue - generation potential, making argument for additional funding of the station.