BHP Ventures, BHP's internal venture capital unit, also joined other investors in a final close of Energy Vault's Series C funding round announced earlier this year.

The MoU is focused on studying the application of Energy Vault's technology to support power supply and energy storage at certain BHP operations while exploring opportunities for new applications relevant to BHP's business. 

The companies will also assess local supply chain collaboration, eco-brick composite manufacturing (including the potential for beneficial re-use of mine tailings or waste), and joint maintenance and monitoring support centres.

"We are excited to deepen our relationship with BHP to support one of the world's largest companies and a global leader in natural resources production to explore applications for our technology in the electrificaiton of their mining operations," Energy Vault co-founder and CEO Robert Piconi said.

"Our company's mission is to accelerate the clean energy transition to make sustainable, decarbonised energy a reality. This MOU demonstrates the strong momentum and demand that we continue to experience for our advanced energy storage technology across multiple industry segments and the most critical energy storage applications."

BHP Ventures head Mark Frayman said collaboration and the development of new technologies will be fundamental to achieving decarbonisation across the global resources industry.

"Energy Vault's technology has the potential to unlock cleaner energy solutions for our operations and create a competitive edge by helping to accelerate our decarbonisation initiatives," he said.  

"This partnership may also present an opportunity to improve life-cycle sustainability by using eco-bricks made with mine tailings, and to create new opportunities for local suppliers."

Energy Vault's advanced gravity energy storage solutions are based on the proven physics and mechanical engineering fundamentals of pumped hydroelectric energy storage, but replace water with custom-made composite blocks which do not lose storage capacity over time.

The blocks can be made from low-cost and locally sourced materials, including the excavated soil at the construction site, but can also utilise locally available waste materials such as mine tailings, coal combustion residuals (coal ash), and fiberglass from decommissioned wind turbine blades.

The Energy Vault systems are intended to minimise environmental and supply chain risks.

The systems are automated with advanced computer control and machine vision software that orchestrate the charging and discharging cycles while meeting a broad set of storage durations starting from 2 hours and continuing to 12 hours or more.