China's 40-story gravity batteries threaten lithium's energy reign
Kaif Shaikh
11–14 minutes


China makes batteries that run on gravity, could be an end run for lithium-ion

Unlike lithium-ion cells, gravity batteries rely on basic physics instead of rare metals.

Updated: Mar 10, 2025 05:31 PM EST

China makes batteries that run on gravity, could be an end run for lithium-ion

With renewables booming and AI driving energy demand higher, gravity-based storage offers a geopolitically neutral solution that could stabilize power grids worldwide.

Gravity Vault

As the global transition toward renewable energy accelerates, storing electricity generated by intermittent sources, such as solar and wind, becomes more urgent. Power production often plunges when the sun sets or the wind dies down. At the same time, demand can surge unexpectedly, placing strain on electric grids that are already juggling the stresses of an electrified future.

Enter gravity batteries, a technology that uses one of the simplest forces in nature—gravity—to store large amounts of energy. This approach, now being trialed in various forms worldwide, promises to offer a cleaner, more durable, and geopolitically flexible alternative to lithium-ion batteries. Here’s what you need to know about the technology, its viability, and some pioneering projects seeking to prove it on a grand scale.
The urgent need for massive energy storage

Renewable energy sources like solar and wind can supply huge amounts of power, yet their outputs are fickle. Production may drop to near zero when the sun isn’t shining and the wind blows. Moreover, the surge of electric vehicles (EVs) indicates a future where electricity demand could skyrocket.

The rapid expansion of artificial intelligence (AI) applications, which require enormous computing power, raises the stakes for stable, reliable energy. Traditional grids can struggle to match fluctuating renewable inputs with these rising demands. Hence, large-scale energy storage—often measured in megawatt-hours (MWh) or gigawatt-hours (GWh)—is essential for ensuring electricity availability whenever needed.

One favored solution to date has been lithium-ion batteries. Although widespread and relatively well understood, lithium-ion technology comes with its problems. Extracting lithium and certain rare Earth elements can be environmentally and socially damaging.

The batteries degrade over time, losing capacity, and they pose challenges in recycling. Their costs fluctuate with geopolitics and supply chain dependencies—China currently controls an estimated 72% of the lithium-ion market. These factors push many governments and companies to explore alternatives that can operate without relying heavily on mined materials.
How gravity batteries work

A gravity battery, at its core, leverages potential energy. Whenever you lift a mass, be it a large block or a volume of water, you invest energy into that mass. Because of gravity, the energy remains stored until the object falls. At any point, you can let it descend controlled, using a generator or turbine to convert the downward kinetic energy back into electricity.

Unlike chemical energy in batteries, which degrades over repeated cycles, gravitational potential energy does not fade with time. As long as mechanical parts remain functional, the stored energy can be released when needed.

Early forms of gravity-based storage have existed for over a century as pumped hydroelectric systems pump water uphill when energy is cheap or abundant and then release it downhill through turbines when electricity demand peaks. The process can be highly efficient and reliable, but it requires a specific geography—elevated reservoirs and large water basins—which many regions lack.

On the other hand, gravity batteries using solid weights can be constructed in more flexible ways, limited primarily by the available height to raise and lower the mass.
China’s bold initiative with EVx

The most striking example of this shift to gravity storage is Rudong, China, where a partnership between Energy Vault (a Swiss company) and the Chinese government has created the EVx system.

Standing over 120 meters high, the EVx building is a massive mechanical tower for lifting giant blocks weighing 24 tons during surplus energy. When the grid demands more power, the blocks are lowered, and their potential energy is converted back into electricity.

Capacity and Efficiency: With a peak power output of 25 MW and an overall capacity of 100 MWh, the EVx has a projected round-trip efficiency of over 80%. Its estimated 35-year operating life suggests a robust long-term solution.

Materials and Construction: Each block is made from readily available substances, such as soil, sand, or recycled waste. Building the tower relies on local labor and local resources. This keeps costs lower than if it relied on imported lithium or other rare metals.

As China pushes heavily toward renewable power, multiple EVx projects are planned, ranging from 100 MWh to 660 MWh systems, and even a proposed 2 GWh installation in Inner Mongolia. Altogether, the capital outlay for these plants exceeds US$1 billion.

Geopolitical Appeal: China’s dominance in lithium-ion supply chains poses a paradox—it benefits from existing battery technology but sees value in proving gravity battery concepts. Should these systems gain international acceptance, other nations could adopt gravity storage without becoming further entangled in China’s vast supply chain for lithium.
Pumped hydro roots and lessons learned

Gravity batteries are not an entirely new concept. Pumped hydroelectric storage, a century-old technology, lifts water from a lower reservoir to a higher one using surplus power, then releases it to generate electricity when needed. Historical examples, such as the early 1907 pump-storage facility in Schaffhausen, Switzerland, highlight the longevity of these systems, which often approach or exceed 90% efficiency.

Nevertheless, pumped hydro demands specific geographic features: large water basins at vastly different elevations. Constructing new dams can be controversial due to environmental, social, and biodiversity concerns.

Gravity batteries use solid blocks and bypass these issues by eliminating the need for water or mountainous terrain. As long as there’s sufficient vertical space in tall buildings or underground shafts, they can be installed in more locations than pumped hydro.

The Gravitricity approach

In Scotland, the startup Gravitricity has tested a 250 kW rig at the Port of Leith, lifting and lowering two 25-ton weights. The demonstration’s success gave proof of concept for dropping one weight after another, smoothing out the power curve.

Now, Gravitricity aims to deploy this technology in abandoned mine shafts. Instead of building a tall structure on the surface, they plan to suspend massive weights below ground. Some mines stretch 3 kilometers deep, vastly exceeding most skyscrapers’ height. That difference translates directly into greater energy storage capacity.

Repurposing unused mines lowers decommissioning costs and breathes new life into local economies. By harnessing existing infrastructure, Gravitricity avoids the heavy capital investment needed to build new towers or water reservoirs. This approach suits regions with historical mining industries, possibly providing a new revenue stream and better energy stability for remote locations.
Challenges and practical limitations

Despite the promise of gravity batteries, they aren’t a universal fix. For personal or home-scale energy storage, the physics involved makes smaller gravity systems inefficient. In one study, engineering students tried lifting a 2,000 kg concrete mass in a house, only to find it stored the energy equivalent of just 12 AA batteries.

Building anything large enough for substantial home storage would be prohibitively expensive and structurally complex. At grid scale, the main drawback of gravity storage is the significant upfront cost. Even though the lifetime operating expenses may be lower than lithium-ions, convincing investors to commit to a high-capital project is not always easy.

Additionally, physical wear on mechanical components like winches, cables, pulleys, or lifts can be a concern over decades of operation. However, advocates note that regular maintenance is straightforward compared with the challenges of recycling chemical batteries.

Another hurdle is real estate. While gravity storage systems do not necessarily need scenic mountain lakes, they require tall structures or deep shafts. Urban areas might balk at constructing enormous towers if they block views or raise property costs. Rural or former industrial sites could be more amenable, but each project’s feasibility depends on local regulations and public acceptance.
Lithium-ion’s limits and a changing energy landscape

Lithium-ion batteries still have advantages in certain applications, particularly for short-term energy balancing and portable devices. They can be installed quickly in many configurations and do not require specialized structures. However, their supply chain complexities, safety concerns (such as fire risk), and environmental impacts make them less ideal for large-scale, long-duration storage.

In the United States, for instance, rising tensions with China have affected trade policies, including tariffs on Chinese goods. With a $500 billion AI budget, the infrastructure is bound to grow, and the need for stable, large-scale storage that doesn’t rely on imported lithium might prove more attractive.

If gravity battery solutions can overcome their initial investment hurdles, they could help U.S. utilities and corporations maintain stable power without being held hostage by fluctuating lithium prices.
The way forward: A balanced energy future

No single storage technology can solve the complexities of modern grids. Instead, experts foresee a mix of solutions, some big and stationary, others small and portable. Gravity batteries, pumped hydro, lithium-ion systems, hydrogen fuel cells, and thermal storage could all coexist, each playing its part.

Gravity batteries shine for large, long-term capacity needs in locations suited to tall structures or deep shafts. Thanks to projects like Energy Vault’s EVx in China or Gravitricity’s mine-shaft designs, the concept has moved beyond the drawing board, demonstrating real potential.

While the technology is still maturing, gravity batteries may stand out for their durability, scalability, and minimal reliance on scarce materials. Over time, if they prove economically viable and robust, these systems could become mainstays for utilities looking to balance renewable energy flows. For the planet, that means fewer greenhouse emissions, reduced reliance on finite resources, and a step closer to a cleaner, more resilient energy future.

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biar dominant di lithium, China tidak segan segan investasi di teknologi saingannya. Semua demi energi security, now that is planning