South Africa’s state owned power utility Eskom has entered into a strategic agreement with Energy Vault Holdings, Inc. to develop large scale gravity based energy storage systems aimed at strengthening electricity reliability and supporting the region’s clean energy transition.
The partnership will begin with the deployment of a long duration Gravity Energy Storage System (GESS) at the Hendrina Power Station in Mpumalanga Province, one of Eskom’s oldest power stations.
The initial project is expected to deliver 25MW of capacity with four hours of storage, equivalent to 100MWh, while remaining scalable to much larger capacity over time.
Under the agreement, the two companies also plan to collaborate on deploying up to 4GWh of energy storage capacity across the 16 member states of the Southern African Development Community (SADC) by 2035.
The initiative forms part of broader efforts to reduce dependence on coal, improve grid stability, expand renewable energy integration, and promote local economic development.
Energy Vault will provide its EVx 2.0 gravity storage technology, including engineering support, project management, equipment supply, and local training programmes.
The upgraded technology includes improvements in energy efficiency, automation, software systems, and construction processes, allowing the platform to scale to multi gigawatt storage capacity.
The system will also make use of recycled coal ash as part of the storage blocks, helping to repurpose industrial waste materials.
Chief Executive Officer of Energy Vault, Mr. Robert Piconi, described the agreement as a major milestone for Africa’s energy future, noting that the partnership would help create jobs, build local supply chains, and accelerate the transition to cleaner energy systems.
Group Chief Executive of Eskom, Mr. Dan Marokane, said the collaboration aligns with Eskom’s Just Energy Transition Partnership goals, which focus on repurposing coal infrastructure while maintaining grid reliability, supporting communities, and reducing electricity costs.
He added that energy storage technologies will play a critical role in integrating renewable energy and strengthening electricity systems across Southern Africa.
According to Eskom, access to electricity across the SADC region has increased from 36 percent a decade ago to 56 percent today, although coal still accounts for more than 80 percent of South Africa’s electricity generation.