Jan 07, 2021 07:00:00

What is the 'gravity energy storage system' that is attracting attention as a low-cost energy storage means?

The cost of solar power generation is expected to be lower than the cost of operating fossil fuel power plants in the 2030s, and the amount of electricity supplied by solar power generation is expected to continue to increase. However, with the spread of photovoltaic power generation, which cannot always generate electricity stably, a system for storing surplus power such as pumped storage power generation has been required . Therefore, the Institute of Electrical and Electronics Engineers (IEEE) journal IEEE Spectrum explains the 'gravitational energy storage system', which is attracting attention as a relatively low-cost energy storage means.

Gravity Energy Storage Will Show Its Potential in 2021 --IEEE Spectrum
https://spectrum.ieee.org/energy/batteries-storage/gravity-energy-storage-will-show-its-potential-in-2021

Swiss startup Energy Vault has begun commercial testing of the CDU Arbedo Castione, which uses six cranes installed in a 110-meter-high tower to move a 35-ton concrete block up and down, up to a maximum. A gravitational energy storage system that can store 80 megawatt hours of energy. It is also called a ' concrete battery ' because it uses concrete.

According to Energy Vault CEO Robert Piconi, unlike lithium-ion batteries, which are expensive to recycle , the concrete used in concrete batteries is made from recycled concrete, which has an environmental impact. There are few. In addition, concrete batteries can store the same amount of energy as lithium-ion batteries at half the cost. In addition, lithium-ion batteries gradually deteriorate and need to be replaced, while concrete batteries do not.

Energy Vault has successfully raised $ 110 million in 2019 and plans to start operating concrete batteries in 2021. You can check the appearance of the concrete battery in the following movie.

Commercial Demonstration Unit August 2020 --Arbedo-Castione --YouTube


Scotland-based Gravitricity is also developing a near-practical gravitational energy storage system. The gravitational energy storage system developed by Gravitricity inputs and outputs energy by raising and lowering a weight of 500 to 5000 tons using a discarded shaft with a depth of 1 km.

According to Gravitricity's project development manager, Chris Jandel, Gravitricity's gravitational energy storage system uses a single weight to manage energy, allowing the required power to be input and output quickly and quickly.

Gravitricity's gravitational energy storage system is scheduled to go into test operation in Scotland in 2021, and Jandel says, 'The goal is to develop a system that can input and output energy within one second of receiving a signal.' He says.

Gravity Power , an American company, is developing a system that stores a large amount of water underground and uses that water to move a huge piston up and down to store energy.

To store 6.4 gigawatt-hours of energy in this system, a piston with a mass of over 8 million tons is required. It seems impossible to make a huge 8 million ton piston, but Gravity Power founder Jim Fiske said, 'Modern technology is enough to make an 8 million ton piston.' He says.

Finally, IEEE Spectrum said, 'These gravitational energy storage systems are more economical than systems using lithium-ion batteries, but they are still expensive, but countries around the world have recognized the seriousness of climate change. At times, we will be happy to pay for these systems. '