Modelling Suitable Sites for Solar Harvesting in Rural Areas of Kenya: a Case Study of Kibwezi East and West Sub Counties

Abstract

Project implementors in the photovoltaic (PV) solar farm space have long relied on very little analysis as regards site selection. This in part has been attributed to the fact that small scale solar farm projects requiring relatively low investment costs have been the investment vehicle of choice in the past. With the ongoing need to develop, utility-scale PV solar farms are fast becoming a viable investment vehicle to deliver this valuable resource to even the most rural of communities. Site selection has a direct impact on the power generation performance of the solar farm, economic and social aspects, as well as existing and future infrastructure. Selecting the best site requires a multi-faceted approach. In this study, an attempt was made to model suitable sites for solar PV farms using restriction factors categorized as climatic, topographic, and location factors. The main objective of this study was to model suitable sites for solar harvesting. Using Kibwezi as the study area, several parameters were evaluated using the analytical hierarchy process (AHP). Weighting of parameters was carried out through a process that involved collecting parameter comparison data from respondents in the form of a questionnaire and using the collected data in a pairwise comparison to come up with weights. Reclassification of data and overlay analysis was then carried out in a GIS environment. The resultant suitability map showed areas that were considered on a scale from most suitable to not suitable. The generated map indicated an area of 3,172.8km2 as highly suitable, 904.8km2 as moderately suitable, 169.0km2 as marginally suitable and 3.4km2 as not suitable. The high suitability was primarily influenced by three dominant parameters: temperature, solar radiation, and land use/land cover which when analyzed exhibited strong congruence with solar energy infrastructure goals. It was therefore established that by applying this methodology, it is possible to select suitable sites for solar harvesting based not only on the availability of sunlight in the area but also based on

other cardinal geographical factors. The definition of solar potential should therefore be extended to accommodate other factors. Among the recommendations made is an extension of the methodology to analyze parameters for other renewable energy sources, such as wind, hydroelectric, and geothermal power. It is also suggested that researchers explore the determination of the approximate solar power potential of the study area based on the results of this study.