Energy Vault and Eskom Announce Strategic Development Agreement to Deploy Grid-Scale Gravity Energy Storage Systems in South Africa

Key Takeaways

• Energy Vault to install 25 MW, 100 MWh gravity storage at Hendrina.
• Project targets 4 GWh storage across 16 SADC nations by 2035.
• EVx 2.0 system reuses coal ash, cutting waste and material costs.
• Partnership backs Eskom’s Just Energy Transition, aiming to lower coal use.
• Gravity storage provides four‑hour, long‑duration power to integrate renewables.

Pulse Analysis

South Africa’s power sector remains heavily coal‑dependent, with over 80% of electricity generated from fossil fuels in 2024. As renewable capacity expands, grid operators face the challenge of balancing intermittent supply with demand. Long‑duration storage, such as gravity‑based systems, offers a low‑cost, environmentally friendly way to store excess energy for several hours, smoothing out fluctuations and reducing the need for costly peaker plants. The technology works by lifting massive concrete blocks using surplus renewable power and releasing them to generate electricity when needed, a concept that scales without the chemical constraints of batteries.

The Eskom‑Energy Vault partnership brings this concept to the continent’s largest utility. Energy Vault’s EVx 2.0 platform not only delivers 25 MW of four‑hour storage at Hendrina but also incorporates a novel material‑science approach that repurposes coal‑ash waste into the storage blocks. This reuse cuts material expenses and mitigates the environmental legacy of coal combustion. By licensing the technology and co‑developing projects across the 16‑member SADC region, the two firms aim to install up to 4 GWh of capacity by 2035, creating a regional network of long‑duration assets that can support renewable integration, improve grid resilience, and generate local jobs.

For investors and policymakers, the agreement signals a maturing market for non‑chemical storage solutions in emerging economies. Gravity storage’s long lifespan, minimal degradation, and ability to use locally sourced materials make it attractive for jurisdictions seeking energy security without heavy reliance on imported battery chemistries. As Eskom pursues its Just Energy Transition Partnership, the project could become a template for other utilities in Africa and beyond, accelerating decarbonisation while delivering economic benefits. The success of this pilot will likely influence future financing structures, regulatory frameworks, and supply‑chain strategies for large‑scale storage across the continent.