Identifying and Analyzing the Technical Challenges of Grid Tide Inverters for PV System: A Case Study of Ethiopia and Zambia

Abstract

Zambia and Ethiopia are two countries from southern and eastern of Africa due to their geographical location and other factor the environment condition is different. The research aims at identifying and analszing the technical performance issues of Grid tide Inverter (GTI) for PV system due to operating climate and others factors. In Zambia the study focused on the two main solar plants which is under ZESCO national grid at malty facility zone (MFZ), the first one is the 54 megawatts Bangweulu solar power plant by Neon Investment of France, second one is 34MW Ngonye solar photovoltaic (PV) plant. In Ethiopia eight min off-grid site under Ethiopian Electric Utility(EEU) is included. Beltu, Behima, Mino, Ungoge, Korhele,Tum, Omorate and Kofetu. A survey is conducted focusing on identifying and analyzing the technical performance issues of GTI in the above-mentioned area.
 Using Microsoft excel the environmental \climate condition, Solar radiation, Air temperature, Rain falls and Wind of the two country Zambia and Ethiopia is investigated and analysedfor each selected site. A questionnaire and a Sime structure interview is conducted. The basic inverter challenges are investigated from the collected data and the problem is analyzed based on the specific inverter data sheet. The data sheet of the inverter for each site under this study.
 Finally, the real-time performance of the inverter of the off-grid PV mini-grid system installed in a small remote town in Ethiopia and on-grid PV system from Zambia at multi facility zone is analysed using measured meteorological data. From on- grid and off-grid inverter performance challenges, which the researcher collected from different plant the main ones are climate or environmental effect and also over load. Overload is one of the frequent challenges in koftu, behama and amorita this can be due to high population growth and unexpected power demand from the community. 
 Environmental condition affects almost all solar plant site which is under this study. If we compere the climate of east which is Addis Ababa Ethiopia and southern of Africa Zambia Lusaka. The temperature of Lusaka is higher than Addis Ababa by 5.63°C and even in the plant under this study, temperature rise is one of the challenges on the inverter performance, sensitive electronic component bent due to excessive temperature.
 On the other side in Ethiopia Addis Ababa excessive rain affect the inverter. Finally, Addis Ababa has about 1.32 times more rainfall than Lusaka, (Addis Ababa’s 79.54mm vs Lusaka’s average of 60.34mm). For that reason, most of the inverter in Ethiopia on the mini off-grid site are affected by heavy rain condition.