Ark Energy, a company that sits under Korea Zinc’s Sun Metals has the task of decarbonising the Townsville zinc refinery, which is currently Queensland’s second biggest electricity user and has an energy bill of between $50 million and $80 million a year.

Ark managing director Daniel Kim believes long-duration energy storage that isn’t tied to pumped hydro was “the holy grail of the energy transition’’.

Last month Sun Metals, which has its own solar farm, also bought Epuron which gave it access to a potential 4200Mw of early stage solar and wind projects.

It also bought five hydrogen fuel cell trucks and has a plan to become a hydrogen exporter, a scheme it says would cost $18 billion across the value chain.

“Energy Vault’s innovative solution has the potential to accelerate our plans to decarbonise the Korea Zinc group and help Sun Metals become the most competitive producer of green zinc in the world,’’ Kim said. 

He said long-duration energy storage would allow Sun Metals to time shift renewable energy from the 124Mw solar farm to more valuable periods of the day to increase the overall percentage of renewables in the energy mix and protect the Sun Metals zinc refinery from high wholesale prices.

Sun and Energy Vault expect to begin project deployment in mid-2022 of a storage and energy management software technology.

Energy Vault uses proprietary technology to autonomously orchestrate the lifting and lowering of bricks with a crane-like mechanism, storing the potential energy in the elevation gain and generating then discharging electricity as the bricks are lowered. 

The deal also includes the potential sustainable and beneficial re-use of tailings and other refining waste materials within Energy Vault’s eco-friendly composite blocks. 

Kore Zinc vice chairman Yun B. Choi said Energy Vault’s innovative storage technology and energy management software platform can play a key role in enabling and accelerating the company’s decarbonization strategy.