GravVault Gravity Energy Storage Station Goes Online: Abandoned Mine Transforms into a Giant 'Energy Warehouse'

GravVault Gravity Energy Storage Station Goes Online: Abandoned Mine Transforms into a Giant 'Energy Warehouse'

Swiss company Energy Vault today announced that its GravVault gravity energy storage station has officially connected to the grid in an abandoned iron mine in Valais, Switzerland. The station uses the mine's 600-meter vertical depth to store and release electricity by raising and lowering tens of thousands of 35-ton concrete blocks, achieving a storage capacity of 800 MWh and round-trip efficiency of 87%.

Engineering Breakthrough in Gravity Storage

The principle of gravity storage is simple and ancient—raise heavy objects to height to store potential energy, then release them to drive generators when electricity is needed. But previous gravity storage solutions were constrained by terrain conditions and construction costs, making large-scale deployment difficult.

Energy Vault's innovation lies in using abandoned mines as natural vertical storage space, eliminating the cost of building dedicated towers. CEO Robert Piconi stated at the commissioning ceremony: "There are over 500,000 abandoned mines worldwide—they're sleeping energy warehouses. GravVault technology transforms these industrial relics into clean energy infrastructure."

The process works as follows: when the grid has surplus electricity, motors lift concrete blocks from the mine bottom to surface storage. When electricity is needed, blocks descend under gravity, driving generators through regenerative braking. The 600-meter drop gives each block approximately 200 kWh of potential energy.

Competition with Lithium-Ion Storage

GravVault's primary competitor is lithium-ion battery storage. Tesla Megapack costs approximately $260/kWh, while GravVault targets $150/kWh. Additionally, gravity storage has a lifespan exceeding 50 years—far beyond lithium batteries' 10–15 years—without degradation or thermal runaway risks.

Morgan Stanley clean energy analyst Stephen Byrd noted: "Gravity and lithium storage are not substitutes but complements. Lithium excels at short-duration high-frequency response, while gravity excels at long-duration bulk storage. A mature storage grid requires a combination of technologies."

Global Expansion Plans

GravVault's successful commissioning has attracted global attention. China's National Energy Administration has invited Energy Vault to evaluate gravity storage deployment feasibility in decommissioned coal mines in Shanxi and Inner Mongolia. The US Department of Energy has also announced a $50 million funding program to support domestic development of mine-based gravity storage.

Energy Vault plans to deploy 20 GravVault stations globally by 2030, totaling 10 GWh of storage capacity. Piconi stated: "Gravity storage requires no rare metals, doesn't degrade, and produces no e-waste. It's the perfect marriage of humanity's oldest energy storage principle with modern engineering."

However, gravity storage faces environmental assessment challenges. Installing hoisting systems in abandoned mines could affect groundwater levels and geological stability. Energy Vault commissioned ETH Zurich to conduct an independent geological assessment, which found the mine's structural integrity can support at least 100 years of storage operations.