Not too long ago, when the idea of solar and wind energy was still hotly debated, critics used to point out the limitations of these energy sources: the sun doesn’t always shine and the wind doesn’t always blow. But nowadays many countries’ electricity grids are strongly supplied by renewable energy.

The challenge in creating flexible, reliable and affordable energy supply systems with renewables lies in the very different circumstances across countries and regions. Planning and expanding renewable power must consider countries’ local resources and their existing and planned infrastructure. This becomes even more interesting for countries trying to grow their grids and expand their renewables at the same time – like many in sub-Saharan Africa.

One technology that has the flexibility to complement solar and wind power production is hydropower. It can be used as a constant source of electricity, but also compensate for fluctuations in other sources. But it does need to be properly planned and managed if it’s to be sustainable. //

Can increased electricity generation be harmonised with climate change objectives?

Our research shows that combining sustainably managed hydropower plants with new solar and wind power projects is a promising option for the West African region. It could minimise the use of fossil fuels and their negative climate change impacts as the region seeks to expand access to affordable electricity. //

In our paper, we use a new model to examine the synergies of sustainable hydropower generation with solar and wind power in West Africa. The model shows how to manage these sources in combination.

We show that the region can use hydropower, rather than natural gas plants, to ensure grid reliability while increasing solar and wind power. Natural gas is often touted as a bridging fuel in the transition to sustainable energy. But global emissions need to be around zero by mid-century according to the Paris Agreement. Building more gas infrastructure therefore risks missing climate goals. //

Our paper shows one way to start the renewable transition for West Africa is by optimising the use of local solar, wind and water resources while keeping an eye on sustainability criteria. For instance, our methodology ensures that hydropower lake levels and downstream river flows remain within acceptable boundaries. It also underlines the possibility of replacing future hydropower plants with solar and wind.

This will increase the overall ecological sustainability of renewable power generation.