announced in 2023, alongside construction on three additional grid-scale EVx gravity energy storage system (GESS) deployments in the country.

Following the start of grid interconnection in September 2023, the 25MW/100MWh EVx GESS in Rudong achieved full interconnection after the completion of the final 4km 35kV overhead power line to a remote end substation, as planned with local state grid authorities.

Upon final provincial and state approvals for the start of commercial operation to the state grid, the Rudong EVx will be the world’s first commercial, utility-scale non-pumped hydro gravity energy storage system.

The announcement comes alongside the announcement of new EVx projects between Energy Vault and partners China Tianying and Atlas Renewable on three projects, which commenced in 2023, including:

• 17MW/68MWh EVx GESS deployment in Zhangye City, Gansu Province, being built adjacent to a renewable energy generation site and a national grid interconnection site;

• 50MW/200MWh EVx located in Ziuquan City, Jinta County, Gansu Province;

• 25 MW/100 MWh EVx located in Huailai Cunrui Town, Zhangjiakou County, Hebei Province

The latter two projects were previously announced alongside four other deployments in China and are being built adjacent to renewable energy generation and national grid interconnection sites.

Upon completion, the systems will augment and support the ongoing balancing of China’s national energy grid through the storage and delivery of renewable energy.

“I am pleased to see the increased market adoption of Energy Vault’s gravity energy storage technology in China, the world’s largest energy storage market supported by the new project groundbreaking announcements and other milestones within China’s national energy policy framework for energy storage,” said Robert Piconi, chairman and chief executive officer of Energy Vault, in a release.

China & gravity energy storage pilots

The Rudong and Zhangye City EVx systems were recently selected and announced formally as part of a list of projects with the classification of “new energy storage pilot demonstration projects” by China’s National Energy Administration (NEA).

Projects selected as demonstration pilots receive increased management oversight by provincial-level energy authorities, supporting progress on construction, data reporting, compliance and safety measures, among other issues of focus.

According to Energy Vault, this highlights the substantial surge in demand for renewable energy sources and emphasises the role of gravity energy storage in China’s path to decarbonisation.

China’s energy policies now require renewable energy plants to integrate storage of 20% of their nameplate generation capacity, with at least a two to four-hour duration.

These energy storage durations are expected to increase over time as more renewable energy generation becomes a larger percentage of grid power.

Andrea Pedretti, Energy Vault’s chief technology officer, said: “Having just spent the last few days in Rudong at the EVx site, I continue to be impressed with the local technical, R&D and construction expertise brought by China Tianying and their partners.

“Coupled with their internal and local manufacturing capabilities for all of the mechanical systems, we have a great partner to rapidly deploy our EVx and broader gravity energy storage technology in China.”