PERFORMANCE EVALUATION OF GAS-POWERED GENERATING STATIONS IN NIGERIA: OMOTOSHO POWER STATION (PHASE I) AS A CASE STUDY

Abstract

Electrical energy is the bedrock of civilization and socio-economic development of any society. It is the backbone of technological advancements, effective security, quality life, efficient and productive transportation and communication systems, wealth creation and national prosperity. This research is aimed at evaluating the performance of Omotosho Gas Power Station (Phase I) for the period of 2012 -2017 with a view to ascertaining the factorsresponsible for its underperformance, as may be applicable to other gas power plants in the country. Empirical data of plant’s operations, faults and maintenance status were obtained from the Efficiency Department of Omotosho Gas Power Station (OGPS) in Ore, Ondo State and from the National Control Centre (NCC) in Osogbo, Osun State. The data obtained were collated and analyzed on Microsoft Excel by inputting the key performance indices’ mathematical algorithms to obtain the plant’s performance indices. The results of the analyses show that the Overall Efficiency of the plant ranges from 28.16% to 33.29%. The Thermal Efficiency ranges from 28.73% to 33.97%. The Availability Factor for the plant ranges from 28.55% to 63.83%. The plant’s Capacity Factor average value stands at 32.03% with minimum of 17.82% in 2013 and maximum of 49.98% in 2015. The Plant Use Factor ranges from 61.57% to 80.19%. In all the evaluated parameters, the plant has lower performance indices than international standards. From the results of the study, a number of conditions were responsible for the shortfalls in the performance of the plant such as shutdowns due to disruptions in gas supply to the power station, breakdowns of one or more turbo-alternators, instability of the national grid, overdue of unit(s) overhauls, amongst others. A 256 – state Markov model representing the transition of the eight (8) turbo- alternators of the power station was constructed to obtain the plant’s availability. It was vishown that for 62% of the time, four or five units out of eight units were in operation. This conforms to observation from the data analysis indicating that two of the turbo-alternators (units GT2 and GT4) were down for most of the period under review. Recommendations were also made on how to enhance the output of the station