-Start of construction marks a major milestone for Energy Vault as the company begins its first mobilization of a Battery Energy Storage System (BESS) in the Australian market -Energy Vault, ACEN Australia joined by local officials and Anaiwan First Nations leaders for welcome ceremony at New England Solar in New South Wales

Energy Vault Holdings, Inc. (NYSE: NRGV) ("Energy Vault"), a leader in sustainable, grid-scale energy storage solutions, today announced the start of construction of a 200 MW/2 hour battery energy storage system being deployed at ACEN Australia's New England Solar project. Energy Vault leaders were joined by representatives from ACEN Australia, elected officials and local Anaiwan First Nations leaders at a welcome ceremony to mark the start of construction.

Construction has begun on the first of two previously announced Energy Vault deployments at ACEN Australia's 720 MW New England Solar project near Uralla, New South Wales, with a total planned capacity of 200 MW/2 hours. Once the initial BESS deployment is operational it will be the first large-scale BESS of its kind in the New England Region of New South Wales. The BESS will be charged and discharged on a daily basis and designed to dispatch stored renewable energy at peak consumption hours to help meet the high demand during New South Wales' peak load hours while reducing the region's reliance on coal-fired power generation. It is the first large-scale battery storage project to begin construction with the support of the NSW Government's Emerging Energy Program.

The welcome event, held on-site, featured remarks from Energy Vault and ACEN Australia representatives, including Energy Vault Chief Executive Officer & Chairman Robert Piconi and ACEN Australia's Head of Construction and Engineering, Tim Greenaway, as well as welcome speeches and storytelling from local Anaiwan First Nations leaders. In addition to remarks and storytelling, Anaiwan First Nations representatives conducted a traditional sweating ceremony to commemorate the groundbreaking, which was followed by Mr. Piconi officially breaking ground on the site. New England Solar is being built with the strong partnership of the Anaiwan First Nations.

"Today's groundbreaking is a significant milestone for Energy Vault's rapidly growing commercial footprint in Australia, and we're very pleased to be working with ACEN Australia, its First Nations partners and the Uralla community on the project," said Lucas Sadler, Vice President of Sales Asia, Energy Vault. "New England Solar will serve as a critical source of renewable energy for the NSW region, and Energy Vault's involvement is reflective of the company's truly global approach to meeting the growing demand for reliable and cost-effective energy storage solutions."

"As New England Solar progresses toward completion, we are fortunate to not only have the opportunity to partner with the Energy Vault team in the development of energy storage systems, but to have the strong support and partnership of the Anaiwan First Nations and local community," said Tim Greenaway, Head of Construction, ACEN Australia. "It is our goal to reliably provide clean power in the most efficient and cost-effective manner possible, and today we are one step close to achieving that mission."

The BESS deployments, developed under Energy Vault's B-VAULT™ suite of fully integrated battery energy storage solutions, will be coupled with a special inverter, which enables advanced grid support functionalities such as voltage and frequency ride-through, grid support during disturbances, and reactive power control. The use of the special inverter, combined with Energy Vault's proprietary X-Vault integration platform and Vault-OS Energy Management System to control, manage and optimize the BESS operations, will allow for superior energy management capabilities.

The mobilization of this BESS deployment represents a critical milestone for Energy Vault's growing commercial footprint in the Australian market, following a series of recent agreements, including with Enervest and the Victorian government-owned State Electricity Commission (SEC). To date, Energy Vault's B-VAULT portfolio in the Australian market consists of 1.9GWh in previously announced projects.

About Energy Vault

Energy Vault® develops and deploys utility-scale energy storage solutions designed to transform the world's approach to sustainable energy storage. The Company's comprehensive offerings include proprietary gravity-based storage, battery storage, and green hydrogen energy storage technologies. Each storage solution is supported by the Company's hardware technology-agnostic energy management system software and integration platform. Unique to the industry, Energy Vault's innovative technology portfolio delivers customized short-and-long-duration energy storage solutions to help utilities, independent power producers, and large industrial energy users significantly reduce levelized energy costs while maintaining power reliability. Utilizing eco-friendly materials with the ability to integrate waste materials for beneficial reuse, Energy Vault's G-Vault™ gravity-based energy storage technology is facilitating the shift to a circular economy while accelerating the global clean energy transition for its customers. Please visit www.energyvault.com for more information.

About ACEN Australia

ACEN Australia is the platform representing ACEN's renewable energy assets in Australia. With more than 1 gigawatt (GW) capacity of large-scale renewable energy generation in construction and operations, and more than 13GW capacity in the development pipeline, its portfolio includes solar, wind, battery and pumped hydro projects across Australia.

New England Solar (Stage 1) in NSW is ACEN Australia's first operational project which commenced generating in 2023. Stubbo Solar in the NSW Central West Orana Renewable Energy Zone is ACEN Australia's second project, which is currently being commissioned and will be in full operation by mid 2025.

With 100+ employees and growing, our people are based in Tasmania, Victoria, New South Wales, Queensland and Western Australia.

www.acenrenewables.com.au