Objective & Background
The potential for solar power, wind power and hydropower in West Africa is immense, but remains largely underexploited. However, with solar and wind costs dropping, a strong increase in weather- and climate-dependent renewable electricity generation is expected in the decades to come. This is underlined by West African countries’ policy focus on hybrid renewable power mixes for increasing electricity access.
Previously, we showed the temporal synergies between solar and wind power potential in West Africa to be more widespread than previously believed (Sterl et al. 2018). Nevertheless, synergies between intermittent resources are not enough: the question remains how intermittent supply could be balanced to meet variable power demand.
Method
The hydropower sector presents an opportunity for such balancing. Several West African countries rely strongly on hydropower and have ambitious hydro capacity expansion plans. Allowing existing and future hydropower to be used flexibly to meet peak demand and cover deficits in solar and wind power production could thus be a promising avenue to increase the renewable share in the power mix (Danso et al. 2018).
Our research focuses on exploring the potential interplay between flexible hydropower, solar power and wind power across West Africa, from national to regional scales. To this end, we developed a model (REVUB, “Renewable Energy Variability, Upscaling and Balancing”) to optimize the hourly dispatch of hydropower to balance variable solar and wind power supply with demand, while complying with environmental flow requirements. The model’s input is provided by a hybrid data product comprising climate reanalysis and hydrological model results.
Principal Findings
We demonstrate that the potential for using hydropower to integrate solar and wind power into West African electricity generation mixes would be immense. The ECOWAS (Economic Community of West African States) Renewable Energy Policy foresees solar and wind power delivering less than 2% of demand by 2030, but our results show that flexible management of existing and planned dams in West Africa could allow for 5-10 times more solar and wind to be successfully integrated into the power mix.
Exploiting solar-wind synergies increases the level of renewables’ integration that hydropower can support. Differences in the hydro-solar-wind potential between individual countries are pronounced, implying regional interconnections may be important in the future to fully exploit the balancing potential of hydropower.
Conclusion
Our findings suggest that intermittency of renewable electricity sources is not a bottleneck for increased policy ambition in West Africa in terms of renewable electricity penetration, as the existing and planned hydropower capacity could deliver balancing services supporting grid integration of a much higher renewable share than what is currently targeted. Thus, moving from rigid to flexible dam management may represent an important lever towards leapfrogging fossil technologies in West Africa.