Power utility Eskom and and NYSE-listed grid-scale energy storage solutions provider Energy Vault have signed a strategic development agreement to deploy long-duration gravity energy storage systems (GESSs) in South Africa and, eventually, also the rest of the Southern African Development Community (SADC).

The first GESS plant will be built at Eskom’s Hendrina power station, in Mpumalanga. The system is expected to provide 25 MW of capacity with four hours of storage, equivalent to 100 MWh, and is designed to be fully scalable up to 4 GW.

The agreement establishes a partnership between the two companies, aligning their long‑term interests to accelerate the decarbonisation of Southern Africa’s power sector, the parties state, with Eskom noting that the collaboration supports its Just Energy Transition Partnership initiative, which is focused on achieving a sustainable and equitable transition away from coal while ensuring grid reliability, job creation and local economic development.

“Eskom is committed to reducing the environmental impact of its electricity generation activities and will continuously drive projects to support South Africa’s local and global emission reduction targets and transition responsibly. Eskom’s strategy is designed to position us as a resilient and competitive energy leader in a liberalised energy market. 

"We will drive a just and inclusive energy transition that includes intensifying the repowering and repurposing of coal power stations and exploring clean coal technologies and solutions using technology as a strategic enabler to improve efficiencies and lower the cost of electricity. This partnership with Energy Vault and its innovative gravity storage technology will play a pivotal role in achieving our Just Energy Transition goals,” says Eskom CEO Dan Marokane.

Energy Vault chairperson and CEO Robert Piconi adds that the agreement with Eskom represents a transformational milestone for Energy Vault and for Africa’s energy future.

“By combining our breakthrough EVx 2.0 platform with Eskom's extensive power generation, grid expertise and regional reach, we're not only advancing long-duration storage at unprecedented scale but also pioneering a new model for sustainable industrial development. This partnership will create local jobs, establish resilient supply chains and demonstrate how gravity energy storage can accelerate Africa's transition from coal dependency to energy independence and security – all while delivering reliable, affordable power to communities that need it most."

Under the terms of the agreement, Energy Vault will provide Eskom with its latest EVx 2.0 GESS technology system and associated equipment, together with on‑site engineering, project management and localised training support. The parties intend to license, co‑develop and collaborate on the deployment of up to 4 GWh of GESS storage, with significant potential across the 16-member SADC region by 2035.