Coupling energy, meteorology, hydrology and climate science to optimize renewable power planning in West Africa

Many countries in the developing world have immense, but underexploited, renewable electricity potentials. A good example are the countries in the Economic Community of West African States (ECOWAS). Historically, renewable power generation in West Africa has focused on hydropower, which produces around 20% of the region’s overall electricity generation, with natural gas providing most of the remainder; future capacity expansion plans for the region are also focused to a large extent around gas and hydropower.

 

However, dropping costs for modern renewable power sources, primarily solar photovoltaic and wind power, are expected to break the West African gas-hydro-paradigm in the near future. Given the currently low levels of generation and strongly increasing power demand in many countries, they can be seen as “greenfields” for integrating variable renewable energy (VRE) sources into stable power mixes and planning transmission capacity expansion to the benefit of VRE sources.

 

Such planning requires a nuanced view of the role that different resources can play in a power mix. Solar and wind power are clean and have low environmental impact, but show pronounced diurnal and seasonal cycles, which requires increased power system flexibility across a wide range of time scales. Globally, such flexibility is currently mostly delivered by natural gas, whose use in the future must be limited to comply with the goals of the Paris Agreement. Reservoir hydropower is an alternative source of flexibility, but only if adequately managed across all involved time scales and without endangering environmental flow requirements.

 

In this research, we combined energy science, meteorology, hydrology and climatology to conduct a scenario-based analysis of smart renewable expansion strategies for West Africa using the REVUB model, considering all time scales ranging from hourly to decadal (including climate change effects) and all spatial scales from point to subcontinental. We show that smart management of hydropower plants, smart designs of solar-wind mixes, and smart planning of regional interconnections can ensure reliable and stable power provision while reducing future natural gas demand and at the same time avoiding ecologically damaging hydropower overexploitation. These results have wide implications for energy policy planning far beyond West Africa, particularly in hydro-dependent developing countries.