Assessment of Technological Feasibility of Converting Open Cycle to Combined Cycle Gas Power Plants

Abstract

This study assessed the technological feasibility of converting open cycle to combined cycle gas power plants. The study was carried out on all the operational power plants in Nigeria, using both primary and secondary data sources. The data collected were analyzed using descriptive statistics. The results showed that out of the 72 open cycles and 5 combined cycle units considered, 60.0, 0, 33.3 and 6.7 % of the power plants had turbines that were installed between 1-5 years, 6-10 years, 11-15 years and 16 years and above, respectively. Similarly, 66.6 and 13.3 % of the plants had General Electric and Siemens machines installed in their plants. The power plants ran efficiently with a heat rate and thermal efficiency range between 9.33 to 14.44MJ/KWh, 25 to 39 % for open cycle plants and 6.63 to 11.97MJ/KWh, 30 to 54 % for combine plants. The result also showed that by using the average generation of each plant in the last 3 years as a baseline for conversion, an additional 1142.1MW would be obtained after conversion to the combined cycle without an increase in gas consumption. The study concluded that conversion of the gas turbine from open cycle to combined plants is technologically viable and an additional generation of 1142.1MW can be obtained.