Meridian Energy’s Ruakākā Battery Energy Storage System was officially opened today. Photo / Supplied
Meridian Energy’s Ruakākā Battery Energy Storage System was officially opened today. Photo / Supplied
Meridian Energy says its Ruakākā Battery Energy Storage System (Bess) will give the hydro power generator some much-needed variability in terms of what it can offer the national grid.
Bess, New Zealand’s first large-scale grid battery storage system, was officially opened on Friday.
The facility has a maximum output of100 megawatts of electricity and storage capacity of 200MW hours – enough to power about 60,000 average households during winter for a two-hour period.
Construction of the Bess, just south of Whangārei, began in the first quarter of 2023 and has been completed inside the project’s original $186 million budget.
Meridian’s general manager development Guy Waipara said Bess would add a North Island storage asset to New Zealand’s electricity system.
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“It gives us the ability to load shift between price periods, smooth out peak periods, provide greater resilience to Northland and enable Meridian to participate in the North Island electricity reserves market,” he said.
While construction of Bess is complete, some steps remain before it can become fully operational.
Meridian’s focus has now turned to the neighbouring $227m, 130MW Ruakākā Solar Farm, with construction set to begin in August 2025.
Together with the Bess, the two will form Meridian’s Ruakākā Energy Park.
Ruakākā is part of Meridian’s plan to invest $3 billion on renewable power generation over the next five years.
Meridian Energy's Guy Waipara says it will soon be able to participate in the North Island electricity reserves market.
The company has four other projects already consented, including another Bess in Manawatū, and several others progressing through consenting processes.
In addition to Manawatū, Meridian intends to incorporate batteries into a number of new solar farm projects.
Meridian’s head of wholesale operations Chris Garr said the company is already an “expert” on hydro and wind-powered electricity generation.
“At any one stage we can have years where there’s no wind and there’s not much water – like last year – but broadly speaking, wind and water works really well,” he told the Herald.
“Water is quite reliable over three months to six months, but that’s where its reliability runs out because it’s quite variable over a year.”
Wind is more reliable over a year than water, he said.
“But what it allows you to do is take power when there’s an oversupply and move it into periods where there’s an undersupply of power,” Garr said.
“So, it allows us to move energy around.”
It also allows for the purchase of energy when it is cheap and selling it later at a higher price.
“A battery ideally takes in power when the price is low and discharges it when the price is high,” he said.
On average, the battery would probably sit at about 60 to 70% charged, allowing the company to buy cheap power when prices collapse.
“Then you would move up to a 100% charge, but you’ll be wanting to get it back down to around that 60%, 70% charge relatively quickly so that if other opportunities come up, you can take advantage of them.
“It’s just as important to be able to seek opportunities to buy low and then to sell higher.”
Garr said Meridian was noticing growth in power demand and higher demand peaks, particularly in winter, which is where batteries would step in.
Jamie Gray is an Auckland-based journalist, covering the financial markets and the primary sector. He joined the Herald in 2011.
