Material Insights · Understanding the Material World

Gravity storage: Impact and additionality

Giving closing mines and waste concrete a new job

What this tab covers The impact and additionality lens: what it displaces on the grid, who gains and who bears the burden along the supply chain, and what happens at end of life.

Gravity storage could reuse waste materials and old mines, but it is unproven at scale and its main developer has moved most of its business to batteries.

Grid decarbonisation versus fossil displacement

Mixed

At 4 hours, block systems mostly shift wind or solar within a day, overlapping with lithium batteries. Beyond Rudong, Energy Vault and its partners reported nine more EVx projects in China totalling 3.7 GWh; Rudong plus the three of those under construction came to 468 MWh in early 2024. Energy Vault's 2024 annual report says its gravity technology has largely been commercialised through licences, while the projects it owns itself are a battery plant and a hydrogen and battery microgrid, a signal that gravity is not its main growth line.311

Further EVx pipeline, China (beyond Rudong) 9 projects, 3.7 GWh3 Rudong plus three under construction (2024) 468 MWh3

Just transition and local community impact

Favourable

Mine-shaft storage is pitched as a second life for closing mines, including the Velenje coal mine in Slovenia and the former Darkov mine in Czechia, which could keep skilled jobs and grid connections in mining regions. Block towers can use local fill and waste, so construction value stays local. Evidence of jobs created is not yet available.8

Mines studied 4 (Finland, Slovenia, Czechia, Germany)8

Circular economy and end of life

Favourable

Weights made from waste, and steel structures, can be reused or recycled at end of life. The main residue is concrete, which can be crushed as aggregate.3

Sources

  1. Energy Vault China gravity ESS project connected to grid; starts building three others Energy-Storage.news, 2024
  2. European deep mine operators looking into underground energy storage MINING.COM, 2024
  3. Energy Vault Holdings, Inc. Form 10-K for fiscal year 2024 US Securities and Exchange Commission (EDGAR), 2025