The Sahel region of Africa spans these eleven countries in the Sahara desert: Chad, Niger, Mali, Mauritania, Senegal, Burkina Faso, Djibouti, Nigeria, Ethiopia, Eritrea, and Sudan. As of 2021, the estimated population of these countries was around 482 million and the United Nations expects the population to reach 898 million by 2050. This enormous population growth poses challenges for the region, including increased pressure on limited natural resources, such as water and arable land.

Fortunately, the region also possesses some of the world's largest aquifers that could provide a solution for the challenges and ample opportunities supporting economic growth. The Nubian Sandstone Aquifer System is one of the largest aquifers in the world spanning across Chad, Egypt, Libya, and Sudan. A recent groundbreaking (pun unintended) discovery of the aquifer beneath Niger identified approximately 50 billion cubic meters of available groundwater with an estimated annual recharge of 2 billion cubic meters. This qualifies Niger as the most groundwater rich country in the Sahel region which is ironic because it is also one of the most impoverished nations on the planet.

Like the rest of Africa, where one-half of the continent’s 1.2 billion population are deprived of electricity, Sahel countries also lack access to electricity. As of 2021, the total installed electricity capacity in the 11 Sahel countries was a mere 23 gigawatts (GW) depriving 52.4% of the population from prosperity. However, if the abundant intermittent renewable energy resources could be harnessed, and the region’s massive underground aquifers could be tapped into for storage, it would be possible to provide clean, reliable, and consistent electricity with the bonus of irrigation water for agriculture.

Solar and wind energy have become less expensive than coal and gas, but add the cost of storage, and intermittent renewables lose to fossil fuels. Consider that more than 90% of the world's energy-storage reside in reservoirs, as part of a remarkable but unsung technology called pumped-storage hydropower. With this concept, motors pump water uphill from a lower reservoir to a higher reservoir and when the water is released downwards via gravity it spins a turbine generating power again. A pumped-hydro installation is like a permanent battery, charged when water is pumped uphill and depleted as it flows downward.

Aquifer Pumped Hydroelectric Energy Storage (APHES) is a novel concept for storing large amounts of energy for the generation of electricity that requires an underground aquifer, a surface reservoir, and a wind turbine power plant. When the wind blows, water is pumped from the aquifer to the surface reservoir where the energy is stored in the form of gravitation potential energy. When the wind does not blow, the water is released from the surface reservoir that turns a turbine located in the underground aquifer to generate electricity. Simply put, after water has been pumped out of the aquifer into the surface reservoir, some of the water can then be released from the reservoir back into the aquifer, reversing the operation of the motor pump to produce electricity as a turbine generator and remaining water can be used for agriculture irrigation.

APHES, utilizing aquifers and a renewable energy source as the power plant, can provide clean and affordable energy for mini-grids and agriculture irrigation in rural and desert regions. This modular and scalable concept, coupled with low-maintenance, make it an ideal solution for clean and reliable electricity and agriculture irrigation water. APFES has the potential to create economic opportunities and improve living standards across the planet contributing to sustainable development and decarbonization.

Driving innovation for developing APHES is the $369 billion Inflation Reduction Act with Federal largesse incentives for deploying energy storage projects in the United States. On January 2023, an investment tax credit (ITC) of 30% for stand-alone energy storage facilities became effective and an additional 20% ITC is eligible if deployed in low-income underserved areas. A whopping 50% ITC will incentivize investment for APHES innovations in America for transferring to Africa.