GENERATION PERFORMANCE EVALUATION OF THE KAINJI HYDRO POWER STATION, NIGERIA
The Kainji hydro power initially conceived as the nucleus of the Nigerian power system was rated at 960MW to be supplied by 12 x 80 MW Kaplan turbines. The station was commissioned in 1968 with two 80 MW Kaplan turbo-alternators. Subsequently, other types of turbines and of varying sizes were installed. By 2010, six additional units consisting of two 80MW and two 100MW Kaplan turbines as well as two 120MW Francis turbines were installed bringing the installed capacity to 760 MW. This paper examines and evaluates the performance of the facility of Kainji hydro power generating source. In order to study the performance of this power station, the inflow and outflow data, as well as the generated energy were collected over the period from 1992 – 2008. Various analyses were then performed. Analysis of the inflow data indicates that whilst there was a drought period in the late 70’s and 80’s, the reservoir appears to have recovered sufficiently in the new millennium enough to provide a reliable source of energy. A stochastic model of the station realized as a 128 state Markov process was solved to calculate the gross failure probability for the station. The failure probability of the plants still manifest a behaviour that gives the impression of performance but which when compared to what is expected of such turbo-alternators is unacceptable. An assessment of unit performance was then performed using an index defined as the ratio of the mean-time-between-failures and the mean-time-to repair. These results reveal a performance not entirely dependent on the age of the plants. Indeed the aggregate performance of the Francis turbines despite being the newest was poorer than the aged start-up plants. It further revealed that most of the plants require on the average two days servicing for every five working days. This situation points at an urgent need to refurbish the plants, upgrade the maintenance capability and acquire a good supply of spares for the future, so as to be able to increase the available power generation in Nigeria through a renewable means – hydro.
|Keywords: Power Systems, Hydro Power, Installed Capacity, Generated Capacity, Availability|
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