British company Gravitricity will turn Europe's deepest mine into the first gravity battery.
You've probably never heard of a gravity battery. UK-based energy storage company Gravitricity will soon begin work on converting Europe's deepest mine into the first gravity-based battery.
The mine used to produce zinc and copper and will now store power from the renewable energy sources and feed it into the grid at peak times.
The old zinc and copper mine, 1.444 meters deep, is located in Pyhäjärvi, 450 km north of the Finnish capital Helsinki. It belongs to the Canadian company First Quantum Minerals, and is the deepest mine in Europe.
When it worked, it was the largest source of employment in the area, providing 600 direct and indirect jobs. In August 2022, production from the mine ceased, and so the local community began to explore alternative initiatives for the site.
On the other hand, Gravitricity, an Edinburgh-based company has developed Gravistore, a gravity-based system that can serve as a battery to store excess energy from renewable sources.
On a sunny day or a windy day, when solar or wind farms produce more energy than demand, Gravistore machines can lift the weights placed on defunct vertical mine shafts to store energy.
During times of higher demand, the weights can be allowed to drop to release energy, since the cable winches will serve as electricity generators. Depending on the requirement, the weights can be released slowly or abruptly to meet the energy demand.
Gravitricity will currently use a 530m auxiliary shaft to build a 2MW prototype machine to demonstrate its technology, as it will be the first of its kind in Europe.
Advantages
Gravity-based energy storage systems have been attempted before, in various forms. They are considered viable alternatives and better than lithium-ion battery storage systems.
In comparison, Gravitricity's solutions use existing infrastructure, such as deep-sea mines, that can be reused once mining operations cease. This approach not only provides new employment opportunities in the remote areas where these mines are located, but also provides energy storage features similar to lithium-ion batteries.
For example, gravity-based batteries can go from zero to full power in less than a second. They are also modular, allowing designers to adjust its capacity based on local conditions and requirements.
The technology is superior to lithium-ion batteries in performance and cost. Li-ion batteries often suffer from internal energy loss problems, but gravity-based batteries do not.
The system is also much cheaper to develop and operate and is not limited to a finite number of cycles or years to provide energy storage.
