Exploring Projected Groundwater Sustainable Yield Across African Countries with Implications for Green Hydrogen Production

Abstract

Africa's abundant renewable energy resources position it to play a crucial role in achieving carbon neutrality and meeting climate targets. Green hydrogen, in particular, holds promise for clean energy generation, transportation, and storage. To make green hydrogen production successful, understanding water resource availability, including future projections, is vital. Our study focuses on assessing groundwater resources across diverse African countries and their relevance to green hydrogen production. We conduct a spatio-temporal analysis, considering groundwater recharge, human water use, the HWU/GWR ratio, and groundwater sustainable yield. We examine two climate scenarios (RCP 2.6 and 8.5) from 2015 to 2100 to identify trends in groundwater recharge and water use in fifty-one African nations. Our methodology combines water balance assessments and statistical analysis. We utilize meteorological data from Global Climate Models (GCMs) and Regional Climate Models (RCMs) as input for the Community Land Model (CLM) to calculate groundwater recharge. Additionally, the PCRGLOBWB global hydrological model simulates human water use. Our findings highlight significant variations in groundwater recharge and the HWU/GWR ratio across regions. Some areas, such as West Africa (coastal regions), Central Africa (near the equator), and Southern Africa, demonstrate substantial potential for long-term green hydrogen production due to promising sustainable groundwater yields. However, regions like the Sahara zone, encompassing Mali and Niger, do not exhibit significant sustainable groundwater recharge yields for green hydrogen. Climate change impacts are noticeable in the trends, especially in Northern Africa, where groundwater recharge is decreasing. These insights emphasize the dynamic nature of groundwater resources and their critical role in sustainable water management and the advancement of green hydrogen initiatives in Africa.