Can basement aquifers sustain the transition to solar powered pumping?

The growing pressure for transitioning away from hand-pumped boreholes to powered pumping and reticulation has focused more attention on solar pumping. Many of these schemes in Africa are implemented on crystalline-rock aquifers which occupy approximately 40% of sub-Saharan Africa. Here we discuss the potential for solar pumping, and the system requirements for schemes to be sustainable in the long term. From a hydrogoelogical perspective there are 3 main issues to consider: the transmissivity of the aquifer, the long term recharge, and also the borehole design. Equally important are the financial, engineering, regulatory and social technical interaface. We explore whether boreholes that are drilled for handpumps can be repurposed to house solar pump capability of generating a larger supply, and what steps should be taken to improve the chances of success. The study draws on data from handpumps across several countries in Africa, and detailed modelling of the performance of individual solar pumping systems.