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

Summary:

• Eskom and Energy Vault are announcing an agreement to deploy a gravity storage system at the Hendrina Power Station in Mpumalanga province, South Africa, with intention to license, co-develop and partner to deploy up to 4GWh of long duration energy storage across 16 SADC member states
• The partnership will advance regional efforts to transition away from coal, leverage joint material science technology for economic re-use of waste coal ash within the energy storage medium while enabling grid reliability, job creation, and local economic development

Energy Vault Holdings, Inc., an active player in sustainable, grid-scale energy storage and AI compute infrastructure solutions, announced a strategic development agreement with Eskom Holdings SOC Limited (“Eskom”), South Africa’s state-owned electricity utility, to deploy a long-duration gravity energy storage system (GESS).
The first GESS plant will be built at Eskom’s Hendrina Power Station in Mpumalanga, South Africa, one of the utility’s oldest operating stations. 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 4GW. This landmark agreement establishes a partnership between the two companies, aligning their long‑term interests to accelerate the decarbonization of Southern Africa’s power sector.

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 localized training support. The partnership intends to license, co‑develop, and collaborate on the deployment of up to 4 GWh of GESS storage, with significant potential across the 16-member Southern African Development Community (SADC) region by 2035.

Energy Vault’s EVx 2.0 GESS platform incorporates significant advancements over the previous EVx design, particularly in the software orchestration, mechanical operation, energy efficiency, construction automation, and construction tooling. These enhancements enable a system capable of scaling to multi-gigawatts (GW’s) of efficient energy storage to support growing renewables penetration. The EVx 2.0 design also features improved material science technology for the economic re-use of ash from coal combustion as the storage medium in the blocks, which may weigh up to 25-30 tons each.

“This landmark agreement with Eskom represents a transformational milestone for Energy Vault and for Africa’s energy future,” said Robert Piconi, chairman and CEO. “By combining our breakthrough EVx 2.0 platform with Eskom’s extensive power gen, 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.”

This collaboration directly supports Eskom’s Just Energy Transition Partnership (JETP) 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 gen 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,” said Dan Marokane, Group Chief Executive, Eskom Holdings.

Southern Africa is undergoing a dynamic transformation in its energy landscape, with governments and utilities across the SADC region working to expand access to reliable, affordable, and sustainable electricity. Today, 56% of the SADC region’s population has access to electricity, up from just 36% a decade ago, reflecting the impact of coordinated regional efforts and investment in infrastructure. Coal remains the dominant source of power gen, contributing over 80% of South Africa’s electricity supply in 2024, but the region is actively diversifying its energy mix. Utility-scale energy storage technologies are set to play a key role in integrating renewables, strengthening national grid resilience, and improving grid reliability – while also unlocking new opportunities for industrial growth, job creation, and community development.

This agreement positions Eskom and Energy Vault as regional leaders in grid-scale, long-duration storage and underscores both parties’ commitment to driving a clean, just, and resilient energy transition for Southern Africa.