Eskom and US-based gravity energy storage company Energy Vault have signed a strategic development agreement to explore the deployment of grid-scale gravity energy storage systems in South Africa.
According to the parties, the agreement includes plans to develop a 25 MW/100 MWh gravity energy storage demonstration project at Eskom’s Hendrina power station in Mpumalanga. The project is part of Eskom’s broader strategy to repurpose coal power station infrastructure as part of the energy transition.
The companies say the gravity storage system will use Energy Vault’s EVx technology, which stores energy by lifting and lowering composite blocks using cranes and regenerative braking systems.
The agreement also includes plans to assess broader deployment opportunities across South Africa and the Southern African Development Community with a target pipeline of up to 4 GWh.
Energy Vault says the systems could support grid stability, renewable energy integration and long-duration energy storage requirements.
The projects may incorporate locally sourced materials, including coal ash, into the composite storage blocks used in the gravity storage systems, the companies point out.
Eskom Group Executive for Generation Bheki Nxumalo says the agreement is part of Eskom’s efforts to explore technologies that can support grid resilience and repurposing initiatives at coal-fired power stations.
Energy Vault CEO Robert Piconi says South Africa presents a strategic opportunity for long-duration energy storage development due to growing renewable energy deployment and grid flexibility requirements.
