Scientists are exploring how to use lifts in high-rise buildings for energy storage
Millenium Tower, the second-tallest building in Austria with 50 floors. Credit: Wizzard, Public Domain
Researchers at the International Institute for Applied Systems Analysis (IIASA) in Austria have come up with a proposal that uses lifts in tall buildings to store energy.
The concept is based on potential energy – the energy that is stored in an object due to its position. Energy can be stored by raising an object’s elevation, such as a wrecking ball that is positioned to strike. This energy could then be released to provide power to a grid when required.
The IIASA researchers have proposed storing energy by lifting wet sand containers or other high-density materials, which are transported remotely in and out of a lift with autonomous trailer devices.
The team said this idea, called Lift Energy Storage Technology (LEST), would not require additional investment or space occupancy as lifts already exist in high-rise buildings. It could also create additional value for the power grid and the building owner.
“I have always been fascinated with topics involving potential energy – in other words, generating energy with changes in altitude, such as hydropower, pumped storage, buoyancy and gravity energy storage,” said Julian Hunt, lead author of the team’s study. “The concept of LEST came to me after having spent a considerable amount of time going up and down in a lift since recently moving into an apartment on the 14th floor.”
The researchers said there are more than 18 million lifts in operation globally, with many of these spending a significant amount of time sitting still. The idea of LEST is that when the lifts are not being used to transport people, they can be used to store or generate electricity. This would effectively turn high-rise buildings into batteries, helping the energy grid and improving the power quality in urban areas.
“The coordinated utilisation of such distributed resources alleviates the need for investment in large-scale central storage systems,” study co-author Behnam Zakeri said.
The researchers noted in their study that power capacity is already installed in the regenerative braking systems of lifts, making this concept easier to implement. But they added that the concept still has ideas to be fleshed out, such as finding room to store the weights at the top of buildings when the system is fully charged, and at the bottom of buildings when the system is discharged.