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Linking solar and wind power in eastern Africa with operation of the Grand Ethiopian Renaissance Dam


Ethiopia, Sudan and Egypt are currently embroiled in a politically charged conflict that surrounds the soon-to-be-completed Grand Ethiopian Renaissance Dam (GERD), with Ethiopia’s energy objectives purportedly conflicting with the water needs in Sudan and Egypt. Here we show that the multiple political and environmental challenges that surround GERD could be mitigated by explicitly coupling its operation to variable solar and wind power, which would create an incentive for Ethiopia to retain a seasonality in the Blue Nile flow. We found that this could deliver fivefold benefits across the three countries: decarbonizing power generation in the Eastern Africa Power Pool; allowing compliance with Sudan’s environmental flow needs; optimizing GERD’s infrastructure use; harmonizing the yearly refilling schedules of GERD and Egypt’s High Aswan Dam; and supporting a strong diversification of Ethiopian power generation for domestic use and for Eastern Africa Power Pool exports. These results argue for an explicit integration of complementary hydro, solar and wind power strategies in GERD operation and Eastern Africa Power Pool expansion planning.

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Fig. 1: Hydro, solar and wind power in the Blue Nile countries.
Fig. 2: Load following with GERD and VRE.
Fig. 3: GERD outflow, environmental flow deficit and hydroturbine use.
Fig. 4: Coordinated GERD–HAD operation.
Fig. 5: Cross-border electricity exchanges between Ethiopia and Sudan enabled by joint GERD–VRE operation.
Fig. 6: Ethiopian power mix by 2030.

Data availability

The map in Fig. 1a was created using QGIS, which can be downloaded from The river shapefiles in Fig. 1a are available from Chawanda et al.55, as are the SWAT+ simulation results. The country shapefiles in Fig. 1a are available from Coordinated Regional Climate Downscaling Experiment—Africa data are available at EWEMBI forcing data can be accessed at Data related to solar PV yield were obtained from the Global Solar Atlas 2.0 (ref. 37), a free, web-based application developed and operated by the company Solargis s.r.o. on behalf of the World Bank Group, utilizing Solargis data, with funding provided by the Energy Sector Management Assistance Program (ESMAP). Additional information is available via Data related to wind turbine yield were obtained from the Global Wind Atlas 3.0 (ref. 38), a free, web-based application developed, owned and operated by the Technical University of Denmark. The Global Wind Atlas 3.0 is released in partnership with the World Bank Group, utilizing data provided by Vortex, using funding provided by the Energy Sector Management Assistance Program (ESMAP). Additional information is available via Source data for all Figures are provided in spreadsheet files along with this paper, containing the raw data used to create the plots.

Code availability

The REVUB model code is available at under the MIT license, for Python as well as MATLAB. All data used to run the REVUB simulations and perform other calculations can be obtained from the authors upon request.


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S.S., S.L., H.K. and W.T. acknowledge research funding from the project CIREG (Climate Information for Integrated Renewable Electricity Generation), which is part of ERA4CS, an ERA-NET Co-fund action initiated by JPI Climate, funded by BMBF (Germany), FORMAS (Sweden), BELSPO (Belgium) and IFD (Denmark) with co-funding from the European Union’s Horizon2020 Framework Program (Grant 690462). D.F. acknowledges research funding from the Research Foundation Flanders (FWO contract 202810/1255221N). We thank A. van Griensven and I. Weerasinghe (VUB) for inspiring discussions and advice, C. J. Chawanda (VUB) for his help with the SWAT+ simulations and A. Devillers (IRENA & Mines ParisTech) for her review of the collected technical hydropower plant data. This work would not have been possible without the help of an anonymous Ethiopian expert and personal friend of S.S., for whose support in the conception, drafting and revision of the paper we are deeply grateful. We do not agree with, or endorse in any way, colonial-era agreements on water allocations between Nile countries.

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S.S. conceived the study, collected the data, carried out the simulations and analysed the results. S.L. and H.K. provided the GERD bathymetry data. S.S. wrote the paper and designed the figures with contributions from D.F., S.L., H.K. and W.T.

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Correspondence to Sebastian Sterl.

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The authors declare no competing interests.

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Peer review information Nature Energy thanks Ana Elisa Cascão, Harald Kling, Yacob Mulugetta and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Notes 1–8, Figs. 1-8 and Tables 1–3.

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Source Data Fig. 1

Statistical source data (model input).

Source Data Fig. 2

Statistical source data (model output).

Source Data Fig. 3

Statistical source data (model output).

Source Data Fig. 4

Statistical source data (model output).

Source Data Fig. 5

Statistical source data (model output).

Source Data Fig. 6

Statistical source data (model output).

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Sterl, S., Fadly, D., Liersch, S. et al. Linking solar and wind power in eastern Africa with operation of the Grand Ethiopian Renaissance Dam. Nat Energy 6, 407–418 (2021).

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