EVALUATION OF LEVELISED COST OF ELECTRICITY GENERATED FROM HOT SPRING GEOTHERMAL RESOURCES IN NIGERIA

(A CASE STUDY OF RAFIN REEWA HOT SPRING, LERE LOCAL GOVERNMENT OF KADUNA STATE)

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Author

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Department of Engineering

ABSTRACT
This study work, Evaluation of Levelised Cost of Electricity Generated From Hot Spring Geothermal Resources in Nigeria aims to investigate the economical and technical prerequisites for electricity generation from Rafin Reewa hot spring located at Lere local government of Kaduna state; a potential development sites. Geothermal energy is thought to have great potential in Nigeria due to the high abundance of sedimentary rocks and numerous hot springs. However, it is still a relatively new technology that has not yet been proved to be economically viable at commercial scale in Nigeria. The study investigated both the technical and economical aspects of geothermal energy as a resource for electricity production. The technical investigation is based mainly on identifying the resource temperature at Rafin Reewa hot spring and subsequently which technology is suitable for use in the study area. In the economical section of the study, the impact of resource flow rate and resource depth (variables) on factors that determine the geothermal power plant construction costs are analyzed. Within each variable, geothermal power plant cost factors are calculated, and subsequently the levelised cost of electricity (LCOE) at power sales of 50MW was evaluated. The result of the study shows that the temperature of the geofluid at the study sites (Rafin Reewa) is 122.14oC, and hence this shows that Rafin Reewa hot spring is a hydrothermal geothermal resource suitable for air-cooled binary power plant. Consequently, the results of the study show electricity generation from geofluid of Rafin Reewa hot spring is viable. On the economic aspect of the study, the result shows that the total plant cost, exclusive of wells, for an air-cooled binary is $663,609,961 (N132, 721,992,200) for 50MW plant capacity at study site. The Levelised Cost of Electricity (LCOE) in cent/kWh is calculated using Geothermal Electricity Technology Model (GETEM). To evaluate the LCOE of the geothermal power plant, the impact of production flow rate and resource depth on the cost factors that influence LCOE were evaluated. The result of the study shows that the LCOE at a flow rate of 100kg/s and a resource depth of 1000m is 43.010cent/kWh (N86.02/kWh). Although both variable parameters influence the LCOE, the study shows that the LCOE is more sensitive to the production flow rate than the depth of the resources.