Designer of world’s tallest building wants to build kilometre-high skyscrapers for energy storage

A render of the kilometre high gravity storage tower.

Not too sure whether to file this one under “Not Likely”, or “Let’s Hope Not”, or both: The architects and engineers behind the world’s tallest building say they are looking to build kilometre-high skyscrapers, including in city CBDs, that could act as giant gravity storage installations.

The New York-based Skidmore, Owings & Merrill, which has designed the 828-meter high Burj Khalifa building in the UAE, and many more of the world’s best known towers, has struck an agreement with US gravity storage company Energy Vault to pursue the idea.

Gravity storage is a bit like pumped hydro, but instead of water it uses solid mass. There are plenty who question its economics – but the basic principal is the higher the structure the better. Hence the proposal to build kilometre-high buildings, possibly in the middle of nowhere, but also in the middle of a CBD.

“Since our founding, SOM has pushed the boundaries of architecture and engineering, redefining what buildings can do for cities and communities,” said SOM partner Adam Semel.

“This partnership with Energy Vault is a commitment not only to accelerate the world’s transition away from fossil fuels, but also to explore, together, how the architecture of renewable energy can enhance our shared natural landscapes and urban environments.”

The proposal, pictured above, brings back memories of another improbable technology proposed more than a decade ago by an Australian based technology hopeful EnviroMission, which wanted to build kilometre high “solar towers” in the California desert.

These structures were mooted to create huge updrafts (hot air rises) that would in turn spin turbines and generate power. MoUs were even signed with local power authorities at the time, but the idea never went anywhere.

Energy Vault has so far built a small pilot plant in France and is commissioning a large 100 MW facility in China that doesn’t look at all like the proposed skyscraper projects considered with SOM because it uses dozens of big blocks. There have been few details about its economics.

Image: Energy Vault

It has other ideas too, including one called EVu, (pictured above) which suggests a “topology-agnostic” and “iconic mixed use real estate” featuring massive towers in what appears to be low rise industrial parks.

Energy Vault has a presence in Australia. It builds conventional batteries too, and recently signed a contract to build two big, conventional lithium ion batteries in NSW, next to what is currently the country’s biggest solar farm.

It has previously flagged MoUs for gravity storage with miners such as BHP in 2021, even using recycled wind blades as the heavy mass. Neither company has responded to Renew Economy queries about where these agreement are at.

There are plenty of skeptics who question the economics, or even wisdom, of gravity storage, particularly given the challenges facing the more conventional pumped hydro industry because of soaring civil construction costs.

One Australian company, Green Gravity, is pursing the idea of using mining shafts to raise and lower massive blocks. These shafts can be between 500m and 2 kms, and have the benefit of being hidden from sight and wouldn’t face the same sort of environmental and planning scrutiny of a kilometre high skyscraper.

Every Vault says the skyscraper storage idea, which it dubs EVu, requires “hollow structure” buildings of at least 300 meters high, and up to 1 km high. It claims these will have the capacity for “gigawatt hours” of storage and a “carbon payback” of three to four years.

It’s not clear why the announcement has been made now, because the work with SOM was flagged in some detail in a lengthy “investor day” presentation hosted by the company earlier this month. Perhaps no-one noticed.

“Our strategic partnership with SOM opens a new multi-billion dollar market segment for Energy Vault focused on the future of sustainability in new building design and energy efficiency,” said Robert Piconi, the chairman and CEO of Energy Vault.

“The combination of our pioneering work in gravity energy storage technology with the global track record and expertise of the most widely renowned engineering, design, and architecture firm in the world will provide the first platform toward delivering accelerated carbon payback in building construction and operation for the first time.”

Maybe Barnaby Joyce – who has always argued that inner city elites should enjoy the fruits of their climate and green energy advocacy. Energy Vault are building the two batteries at the New England solar farm in his electorate. Perhaps he could pop down and discuss the idea of giant towers in the CBDs of Australia cities

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