Hydropower Generation in Merowe Dam in response to Grand Ethiopian Renaissance Dam (GERD)

Abstract

This paper aims to quantify the influence of Grand Ethiopian Renaissance Dam (GERD) on Merowe
Dam (MD) in the context of hydropower generation. MD is located on River Nile (RN) in the North Sudan, about
800 km downstream Khartoum with a total storage capacity of 12.4 Km3. It worth mentioning that, RN annual
runoff is estimated to an average of 85 Km3, formed from Blue Nile (57%), White Nile (29%) and Atbara River
(14%).GERD reservoir capacity is estimated to be 74 Km3, with installed capacity of about 6000 Megawatts,
while the installed capacity of MD is 1250 Megawatts; the average annual energy output is about 6000 Giga-watts
85% of the required water for the generation in MD comes from the runoff river, while the reservoir provides 15%
of water per year.The two main objectives of this study are to quantify the impacts of GERD during first filling
and long term run. Comprehensive study for the RN Hydrological system was performed, using Excel Sheets
designed with Visual Basic for Applications VBA, calibrated and tested. Boundary conditions were established
and different operation policies were applied. It should be noted that, five different scenarios were studied, for the
first impounding during 6 years with a total retaining of water between 10-50% of the Blue Nile yield; the impacts
were limited to a deficit of 10% max.In summary, the effects of GERD on MD are quantified by decreasing in
energy by 10% during first impounding and, increasing in energy by 27% annually for long run.