There are many kinds of renewable energy – wind, solar, geothermal, hydro – but have you ever heard of gravity as a renewable energy source? While these sources stop working at certain times, gravity never lets up, and it could soon become a primary source for energy in multiple large cities. Let’s dive in.

Energy Vault Holdings and Skidmore, Owings & Merrill (SOM) are collaborating on a massive skyscraper project that would generate renewable energy using gravity. Energy Vault works on gravity and kinetic energy-based, long-duration energy storage solutions, while SOM is a major American architecture firm that focuses on tall buildings– the firm is the primary architect for Dubai’s Burj Khalifa, New York’s One World Trade Center, Chicago’s Willis Tower, Shanghai’s Jin Mao Tower, Dallas’ Chase Tower, and Tianjin’s CTF Finance Center. They were also named the number one architecture firm in the United States by Architizer. 

The project would involve a tower that could touch the sky– its height can vary from 985 to 3,280 feet tall. That would be over 500 feet taller than the world’s current tallest structure, the Burj Khalifa, which is 2,722 feet tall. 

Solar and wind sometimes generate excess energy for the grid, which is normally wasted. However, this battery skyscraper would harness that energy when it is generated to lift large blocks to the top of the tower, creating potential energy. Then, when the area is in need of energy, the blocks would slowly drop, creating kinetic energy that will be harnessed by generators to power surrounding homes and businesses. The skyscraper will also have extra space inside for apartments, condominiums, and offices, allowing it to act as a regular building as well.

This process is called grid-scale storage, which is a technology that can store energy when it is generated and then send it to the power grid when it is needed. This project would do exactly that, and it will be crucial for moving away from fossil fuels in the future, as renewable energy may not always be readily available.

Another example of grid-scale storage is pumped hydro storage. Large modules pump water up a hill into another module, and once that energy is needed, it slides back down, passing through a turbine that generates energy. Despite being the largest source of grid-scale storage right now, this process requires lots of space and can only be built on hills, limiting it to certain areas. On the other hand, these gravity battery skyscrapers can be built on any small area of flat land. 

Energy Vault has already completed a gravity-powered energy storage system in Rudong, China, which is 492 feet tall and can store over 100 megawatt hours (MWh) of energy– in comparison, 1 MW can power over 1,000 homes for a year.

SOM and Energy Vault’s first skyscrapers could be coming to the world in another few years, and it could soon become a frequently seen building in cities as grid-scale storage becomes more important.

Image credit to SOM