Contact Energy has officially opened its first grid-scale battery at Glenbrook, South Auckland, which it says will power the equivalent of 44,000 homes for up to two hours at peak demand.

The Glenbrook Ohurua Battery one will produce, at full capacity, 100 megawatts of electricity from largely renewable energy sources, the company said.

The $151 million energy storage system will help provide long-term security to New Zealand’s energy supply, it added.

The battery, built on land leased from NZ Steel, was today officially opened by Prime Minister Christopher Luxon.

With the rapid decline in the gas market, Contact’s new battery system strengthens winter energy resilience, Contact chief executive Mike Fuge said.

“This is more than new infrastructure; it represents a shift in how we power New Zealand’s future,” Fuge said.

“As we move towards a highly renewable system, flexibility from assets like this battery support energy security when the sun doesn’t shine and the wind doesn’t blow.

“It also reduces exposure to global energy shocks and builds a more independent energy system for New Zealand,” he said.

The battery stores largely renewable energy when demand is low and supplies it back to the grid when demand is high.

Contact is also working on Glenbrook Ohurua Battery two; a 200MW project alongside the first battery, representing a further $235m investment.

Together, the batteries will provide up to 300MW of capacity, enough to power the equivalent of 132,000 homes for up to two hours during peak demand.

Jamie Gray is an Auckland-based journalist, covering the financial markets, the primary sector and energy. He joined the Herald in 2011.