Eskom to Test Gravity Energy Storage in South Africa

Why this is here: The initial gravity energy storage system will have a capacity of 100 megawatt-hours, intended to help stabilize South Africa’s grid as it shifts to renewable energy.

Eskom, South Africa’s public utility, and Energy Vault are partnering to deploy a 25MW/100MWh gravity energy storage system at the Hindrina Power Station. The project, located in Mpumalanga province, will use Energy Vault’s EVx 2.0 GESS technology, which lifts and lowers composite blocks to store and release energy. The companies plan to potentially scale the system to 4GW, though a timeline for expansion remains undefined.

They also intend to license and co-develop up to 4GWh of long-duration energy storage across the 16 member states of the Southern African Development Community. The partnership seeks to repurpose waste coal ash as material for the storage blocks, addressing both energy needs and waste management.

Energy Vault’s technology faces ongoing criticism within the energy storage sector, and a UK-based competitor recently entered administration. Eskom hopes this storage will bolster grid reliability as it transitions away from coal and integrates more renewable energy sources. The utility recently experienced a period of over 300 days without blackouts, though challenges with corruption persist.