Evaluation of Solar Resource and Technical Performance of 180kWp Commercial Scale Solar Photovoltaic System at Timau, Kenya

Both developed and developing countries are grappling with the need to meet their increasing energy demand in a sustainable and affordable manner. This has made it necessary to exploit the potential of renewable energy technologies. One of the options that has been considered is the use of distributed commercial scale solar PV systems installed on medium or large energy consuming facilities. The systems are designed to supply part of the energy needs of the facility with the deficit drawn from the utilitys grid. In some cases, the solar PV systems may bank any excess energy generated onto the grid depending on the existing regulatory framework. Success in implementation of these systems requires knowledge on the available solar resource and expected performance of the solar PV systems. In this study, the solar resource potential at Timau area (0.089238 o N, 37.274860 oE), Meru County-Kenya and the performances of a 180kWp ground-mounted Commercial Scale Solar Photovoltaic System installed to supply a flower farm at the location were analysed. In the paper, the design configuration of the solar PV plant is elaborated. The monthly average daily reference yield for the site, annual average daily yield, performance ratio and monthly average capacity utilization factor for the 180kWp plant are also computed. The monthly average daily reference yield based on the monitored solar insolation was found to range between 4.60 - 7.33 kWh/kWp-day. This is 1.1 % higher than the long-term insolation data obtained from the PVGiS database during the hot season and 3.3 % lower during cold seasons. Similarly, the annual average daily yield is 5.21 kWh/kWp-day based on the monitored irradiance values and 4.25 kWh/kWp-day based on the metered energy supplied by the solar PV plant to the flower farm. Lastly, the highest daily average performance ratio for the months of February and March 2017 was 80.8 % and the monthly average capacity utilization factor ranged between 13.28 % - 21.19 % over the one year monitoring period.