South Africa is advancing an ambitious energy initiative that symbolically transforms the legacy of its coal-powered past into clean energy infrastructure. A new 100MWh gravity storage project aims to convert coal ash, the by-product of decades of coal-fired electricity generation, into part of the foundation for a modern energy system that could influence Africa’s broader energy future.
In a landmark partnership, Eskom and Energy Vault are deploying a 25MW/100MWh gravity energy storage system at the Hendrina Power Station in Mpumalanga. The project uses Energy Vault’s EVx 2.0 platform to store electricity not through lithium batteries or pumped hydro systems, but through gravity itself by lifting and lowering massive blocks produced from recycled coal ash.
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More than a futuristic engineering project, the initiative reflects a wider transformation in Africa’s energy sector. It represents a shift from traditional energy dependency toward smarter and more resilient energy systems. Beyond storage technology, the project touches on energy security, industrial renewal, climate adaptation, and regional power integration.
The Hendrina gravity storage system directly addresses one of Africa’s biggest modern energy challenges: intermittency. Although the continent possesses vast solar, wind, and hydroelectric potential, renewable energy generation fluctuates. Solar power disappears at night, while wind generation remains inconsistent, making reliable energy storage essential for grid stability.
Unlike lithium-ion batteries, which degrade over time and depend on rare minerals, or pumped hydro systems that require specific geographical conditions, gravity storage operates differently. Excess renewable energy is used to lift 25–30 tonne blocks, which are later lowered to generate electricity when demand rises. The technology offers long-duration energy storage without chemical degradation or major fire risks. Importantly, the blocks themselves are created using recycled coal ash from Eskom’s existing operations, turning industrial waste into productive infrastructure.
The location of the project carries strong economic and political symbolism. Mpumalanga is South Africa’s coal heartland, and rather than abandoning these regions during decarbonisation, the initiative supports the country’s Just Energy Transition Partnership by repurposing legacy infrastructure, retraining workers, and creating new clean-energy value chains. This approach presents climate transition not as an economic sacrifice, but as industrial evolution, an important distinction in Africa, where energy systems remain closely tied to employment, poverty reduction, and economic stability.
The project also comes at a critical moment for South Africa. Over the past decade, the country’s electricity crisis and rolling blackouts have cost the economy billions of dollars, weakened manufacturing competitiveness, and damaged investor confidence. The crisis has reinforced a broader continental reality: no industrialisation strategy, AI ecosystem, or digital economy can succeed without reliable energy infrastructure.
Although the 100MWh project is currently a pilot initiative, it is intended to scale significantly. Plans aim to expand storage capacity toward 4GW, with broader ambitions to deploy up to 4GWh across the Southern African Development Community region by 2035. This elevates the project from a national experiment to a broader regional energy strategy capable of strengthening cross-border electricity trade, renewable integration, and grid reliability through the Southern African Power Pool.
The implications for Africa are considerable. The continent could emerge as a global leader in alternative energy storage systems that reduce dependence on expensive imported batteries while using locally available materials. Coal-dependent economies may also gain a practical transition model showing how former fossil-fuel regions can evolve into clean-energy infrastructure hubs.
Long-duration storage technologies could further improve the bankability of renewable energy projects by increasing reliability and reducing intermittency risks. This may unlock larger investment flows and encourage greater participation from independent power producers across the continent.
Despite ongoing challenges, including financing constraints, policy uncertainty, and the need to prove large-scale operational performance, the project broadens Africa’s vision of what future energy infrastructure can become. It signals a transition from an era defined by energy scarcity toward one driven by energy intelligence, where electricity is stored, distributed, and optimised through hybrid systems combining solar, wind, hydro, batteries, and gravity-based storage.
The Eskom-Energy Vault partnership ultimately presents a powerful vision for Africa’s energy future: one where old coal infrastructure supports renewable stability, industrial waste becomes part of next-generation energy systems, and African economies help pioneer technologies linked not only to climate goals but also to industrial renewal and economic resilience.
