This paper assessed the variability and projected trends of solar irradiance and temperature in the East of Burundi. Observed temperature from meteorological stations and the MERRA-2 data set provided by NASA/Goddard Space Flight Center are used over the historical period 1976–2005. In addition, solar irradiance data provided by SoDa database were considered. Furthermore, projection data from eight Regional Climate Models were used over the periods 2026–2045 and 2066–2085. The variability analysis was performed using a standardized index. Projected trends and changes in the future climate were respectively detected through Mann-Kendall and t-tests. The findings over the historical period revealed increase temperature and decrease in solar irradiance over the last decades of the 20th century. At a monthly scale, the variability analysis showed that excesses in solar irradiance coincide with the dry season, which led to the conclusion that it may be a period of high production for solar energy. In the future climate, upward trends in temperature are expected over the two future periods, while no significant trends are forecasted in solar irradiance over the entire studied region. However, slight decreases and significant changes in solar irradiance have been detected over all regions.

This study investigated the variability and trend of rainfall and extreme temperatures over three eastern and northeastern regions of Burundi during the period 1980-2015. Data used were collected from seven stations belonging to the geographical institute of Burundi. Annual and seasonal variability are assessed using standardized anomaly, coefficient of variance and precipitation concentration index. In addition, non parametric statistic tests Mann Kendall and Sen’s slope estimator are used to detect trends in rainfall, maximum and minimum temperatures. The results reveal a high monthly and inter-annual variability of rainfall whereas the temperature does not show high fluctuation at monthly scale. The northern region presents the lowest amount of rainfall for the first rainfall season (October-January) when drought is frequently observed. No significant rainfall trend detected over all regions at seasonal and annual scales whereas significant increasing trend was observed for both maximum and minimum temperatures over all regions. The spatial distribution of rainfall and extreme temperatures displays also a wide variation across the region depending on topography of the study area.

This work focuses on analysis of climate change effects on Photovoltaic (PV) power output in the Eastern and Northeastern of Burundi. Monthly temperature data from meteorological stations and solar irradiance data provided by SoDa database were considered as observed dataset for the historical period 1981-2010. Projection climate data from eight Regional Climate Models of CORDEX for Africa were used over the near future period 2021-2050. The change in temperature and solar irradiance were analyzed and the effects of these climate changes were assessed to show their impacts on PV power potential. The results indicated increasing trends and change in temperature for about 2°C over this near future period. The solar irradiance change was revealed negative with a high interannual variation for all regions and the mean decrease ranges between 2 and 4 W/m². The findings revealed also a negative change in PV power potential close to zero for all regions with a high change occurred in NLL. Indeed, the contribution of each parameter to PV power potential change was negative all over regions. However, the projected climate change does not predict a huge PV power potential change by 2050. Therefore, Burundi may invest in producing electricity energy from PV systems.