Energy Vault Holdings announced, along with its partners Atlas Renewable and China Tianying, that the world’s first grid-scale gravity energy storage system (GESS), has entered the first phases of commissioning. The EVx system, adjacent to a wind power facility near Shanghai, is expected to be fully grid interconnected in the fourth quarter of 2023.
Energy Vault has taken a new approach to energy storage. Its solutions are based on the fundamental principles of gravity and potential energy. The EVx platform utilizes a mechanical process of lifting and lowering composite blocks to store and dispatch electric power.
The company built a structure consisting of hollow towers. The facility utilizes excess solar power in the system to pull up the weight, creating potential energy. When needed, the blocks are dropped and electric motors generate electricity. The technology is not much different from pumped storage hydropower.
First gravity storage unit in global market
The project was commissioned by China Tianying Group, which signed a contract with State Grid Corp. of China, the country’s main power network operator. The new system is the first in the world that can balance the grid using gravity, Energy Vault pointed out.
The composite blocks can be made cheaply
Through a waste management subsidiary, China Tianying Group can source cheap materials like mining tailings and coal ash. Energy Vault, which was listed in February at the New York Stock Exchange, said the blocks can also be made from dirt from the construction site of the gravity energy storage system itself or, for instance, fiberglass from decommissioned wind turbine blades.
Energy Vault is developing long-duration gravity energy storage tech
The tower is controlled by computer systems and machine vision software that orchestrate the charging and discharging cycles. The new type of battery storage can operate at full power, 25 MW, for up to four hours – the capacity is 100 MWh.
The company expects to boost the efficiency of its EVx system to above 80%
Engineers from Energy Vault claimed they can reach 12 hours and on a gigawatt-hour scale in the forthcoming endeavors. Moreover, the company expects to top the 80% mark in efficiency. It means it would be able to recover four fifths of the electricity that it consumes. The company’s technology would in that case become competitive in the arena with other long-duration energy storage solutions: pumped storage hydropower plants, compressed air and flow batteries.
The demonstration project installed in Switzerland in 2020 achieved 75% efficiency.
China portfolio turned 20 times larger
The investors expect the EVx system in Rudong in Jiangsu province near Shanghai to be fully connected to the grid in the fourth quarter. The location is next to a wind power plant and a transmission power line.
Energy Vault, headquartered in Lugano, Switzerland, revealed in September that it would set up five more EVx gravity energy storage systems in China, with a combined capacity of 2 GWh. Its partners are Atlas Renewable, one of the company’s stakeholders, together with Chinese nongovernmental organization EIPC and China Tianying, which has telecommunications as its core activity.