This is what an energy storage facility in the form of a skyscraper could look like. (Image source: Energy Vault)
Building large structures has always been a sign of power. Whether the Pyramids of Giza, the Great Wall of China or the Empire State Building, they are all landmarks of their nations.
The currently tallest building in the world is the Burj Khalifa with a height of 828 metersThe skyscraper built in Dubai has 163 floors of apartments, offices, a hotel and the highest restaurant in the world.
If it is up to the two companies Skidmore, Owings & Merrill (SOM) and Energy Vault However, in the future, high-rise buildings will offer another function: the storage of renewable energy.
Gravity for energy storage
One of the biggest hurdles of a power grid that relies primarily on renewable energy is that it is only available intermittently. Solar energy is completely non-existent at night and when clouds appear, the energy yield is lower. Wind does not blow constantly either.
On the other hand, solar and wind produce large surpluses. The challenge is to store these surpluses and feed the energy back into the grid when needed.
One way to store energy is to use gravity
The skyscrapers designed by SOM and Energy Vault will work according to a similar principle (via CNN).
In times of excess electricity, huge weights are pulled to great heights by electric motors and then lowered in reverse to convert the so-called stored energy back into electricity – this is how it looks:
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Skyscraper as 1,000-meter-high energy storage facility
Skyscrapers from 300 to 1,000 meters
The efficiency should be similar to that of pumped storage power plants. It is around 75 to 85 percent. This means that a maximum of 85 percent of the energy used to pump or pull water up can be recovered at the end. This is a very good value.
The following applies: the higher the building, the greater the amount of energythat can be stored. SOM and Energy Vault are therefore planning on buildings with a height of around 300 to 1,000 meters – perhaps a little higher.
SOM already has a lot of experience with tall buildings. The company designed the One World Trace Center and the Burj Khalifa mentioned above, among others. Energy Vault, on the other hand, specializes in the long-term storage of electricity using gravity and kinetic energy.
How far have the plans progressed?
At the moment, the superstructures are still in the concept phase. SOM and Energy Vault are currently looking for partners to realize possible projects.
So it may be a while before we see the first skyscraperswhich also function as energy storage.
However, more and more skyscrapers with a height of over 200 meters are being built. While there were a total of 235 between 1900 and 1999, 179 new skyscrapers of this size were added last year alone.
Criticism of the form of energy storage
There is also criticism of so-called lifting storage or gravity power plants. They can only store relatively little energy. A 150-meter-high plant in China has a capacity of 100 megawatt hours. However, taller buildings can store more.
To put it into perspective: 100 megawatt hours could supply 10,000 three-person households with a consumption of 10 kilowatt hours with electricity for a day.
The height of the buildings is also criticizedas construction costs increase disproportionately the higher a building is. However, the current concept of SOM and Energy Vault envisages adding the function of energy storage to skyscrapers.
Basically, these are normal high-rise buildings that, in addition to apartments, also offer space for corresponding weights including motors and cable winches.
By the way: The tallest building currently under construction is the Jeddah Tower in a planned city on the west coast of Saudi Arabia. Once completed, it is expected to be the new tallest building in the world at 1,007 metres.
However, it may be replaced by an energy storage system sooner rather than later.
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