Exergoeconomic parameters of Ihovbor Gas Power plant were determined in this study. To achieve this, the exergy of each stream, the economic cost of the plant components, the exergetic costs of each stream and the exergoeconomic evaluation of each component were determined. The average exergy efficiency of GTs ONE, TWO, THREE and FOUR were found to be 59.32%, 60.83%, 59.80% and 60.38% respectively and it decreased with increase in ambient temperature. The exergy destruction cost was greatest in the combustor (average of 1596.175$/hr), the relative cost difference was greatest in the air compressor with an average ratio of 0.36585, the exergoeconmic factor of the gas turbine was greatest (91.84%) and the average cost of power generation was found to be $0.0162/kWhr. Exergoeconomic parameters can be used as tools for energy audit and determining the running costs of power plants and power generation.

The result of this study shows the performance of Ihovbor Gas Power Plant in Benin, Edo State Nigeria using first and second law of thermodynamics. Analysing the efficiency of the plant using first law of thermodynamics showed that with increase in inlet air temperature, the energy conversion efficiency of the plant reduces. The exergy efficiency of the plant also confirmed that increase in inlet air temperature results in decrease of the exergetic efficiency of the plant. Analysis of each of the components showed the greatest destruction of exergy was in the combustion chamber while the least is the Gas turbine section. Using numerical method in analyzing the gas turbine plant when retrofitting with an evaporative inlet air cooler showed better performance in energy conversion as power generation increased with an average of  1% per 1oC degree fall in temperature, the work ratio and thermal efficiency of the plant also increased. The analysis of the modified plant using second law of thermodynamics showed an increase in magnitude of both the exergy destroyed and the efficiency of the plant. Analysis showed that integrating evaporative cooler as component of the inlet air cooler increases the efficiency of the Air compressor by over 0.8%  thus increasing the plant’s exergetic efficiency.

The result of this study shows the performance of Ihovbor Gas Power Plant in Benin, Edo State Nigeria using first and second law of thermodynamics. Analysing the efficiency of the plant using first law of thermodynamics showed that with increase in inlet air temperature, the energy conversion efficiency of the plant reduces. The exergy efficiency of the plant also confirmed that increase in inlet air temperature results in decrease of the exergetic efficiency of the plant. Analysis of each of the components showed the greatest destruction of exergy was in the combustion chamber while the least is the Gas turbine section. Using numerical method in analyzing the gas turbine plant when retrofitting with an evaporative inlet air cooler showed better performance in energy conversion as power generation increased with an average of  1% per 1oC degree fall in temperature, the work ratio and thermal efficiency of the plant also increased. The analysis of the modified plant using second law of thermodynamics showed an increase in magnitude of both the exergy destroyed and the efficiency of the plant. Analysis showed that integrating evaporative cooler as component of the inlet air cooler increases the efficiency of the Air compressor by over 0.8%  thus increasing the plant’s exergetic efficiency.