Aquifer conditions, not irradiance determine the potential of photovoltaic energy for groundwater pumping across Africa

Abstract

Groundwater pumping using photovoltaic energy has the potential to transform water services in poorly served areas. Here we develop a numerical model that uses openly available data to simulate the abstraction capacities of photovoltaic water pumping systems across Africa. The first contribution of this article is the detailed design of the large-scale model to include realistic geological constraints on the depth of pumping and sub-hourly irradiance time series. The second one is the provision of results for the whole continent. We simulated results for three system sizes (100, 1000, 3000 Wp) and the daily pumped volumes were found to vary between 0.1 and 180 m3, depending on the size and location. We show that, for much of Africa, groundwater pumping using photovoltaic energy is constrained by aquifer conditions, rather than irradiance. Our results can help identify regions where photovoltaic pumping has the highest potential and help target large scale investments.