A new battery energy storage system is modernising the Northern Territory’s energy grid, a standalone system with no interconnectors to other jurisdictions, to meet future demand through fuel efficiency and system reliability improvements.
The Northern Territory’s power grid has undergone considerable transformation, powered by a new installation on an island in Darwin Harbour.
Until mid-2025, the Darwin-Katherine electricity network relied solely on gas turbines to provide critical grid-stabilising essential system services (ESS), such as supporting network frequency in the event of a generator trip or a network fault.
“The issue with traditional turbines is that it is inherently inefficient to burn extra fuel simply to keep the system stable,” said Territory Generation Principal Electrical Engineer Boyd Hillebrand MIEAust, CPEng.
That’s why Territory Generation, in partnership with technology company Hitachi Energy, developed a new battery energy storage system, or BESS, that could provide fast-response support and operational flexibility, particularly during periods of high and low system demand.
“The Channel Island BESS was a project that took several years of planning, development and construction, and in mid-2025, we completed all testing to enable its acceptance for use on the power system,” Hillebrand said.
“Its fundamental objective was to reduce the need to operate our older, less efficient gas turbines by replacing those services with a battery that doesn’t require fuel.
Ready for action
Using advanced inverter‑based technology supplied by Hitachi Energy, the BESS is designed to compensate for a shortfall of capacity during a system disturbance, such as when a gas turbine generator trips.
“If there is insufficient energy from existing generation, the system slows and network frequency declines,” Hillebrand said.
“The battery can rapidly supplement generation to rebalance supply and demand, allowing frequency to remain within acceptable limits and reducing the need for disconnecting customers to stabilise the network.”
Equivalent to a 32.6 MW gas turbine, the Channel Island BESS comprises eight power trains with 16 power conversion systems and a total of 192 separate battery modules. By reducing Territory Generation’s reliance on gas‑fired ESS, the BESS supports more efficient and flexible operation of the utility’s fleet.
“The primary driver was to improve the efficiency of providing essential system services by eliminating the need to operate a gas turbine solely for frequency support,” Hillebrand said.
“In operation, the BESS has performed as intended during recent power system disturbances, stabilising the network and limiting the extent of interruptions.
“Delivered through Hitachi Energy’s local team with more than 35 years of operational presence in the Northern Territory, the Channel Island BESS provides essential system services that play a critical role in keeping the power system stable and responsive – supporting reliable electricity for homes and businesses across the Territory,” said Juergen Zimmermann, APAC Regional Product Manager, Grid Automation Business, Hitachi Energy in Darwin.
As well as providing economic and sustainability benefits, the Channel Island BESS is on track in its first year of operation to achieve its target savings and has already helped avoid more than 35,000 tonnes of CO2-e.
“Beyond its role in system stability, the BESS can also be used to offset the need to start gas turbines to cover short duration peaks” Hillebrand said.
“Instead of starting a gas turbine for brief, intermittent peaks, the BESS can discharge into the network, reducing unnecessary starts and associated operational and maintenance costs.”
System-wide impacts
Based on the BESS’s performance since it began operation last year, the project payback is expected to be five years.
By reducing the cost of providing the spinning reserve capacity, the BESS helps Territory Generation to avoid running lower-efficiency machines. These fuel cost savings, along with the reduction in maintenance requirements, add up rapidly.
And depending on seasonal demand and operating conditions, the BESS’s capacity is between 10 to 60 per cent of the power system at any given time.
“At 32.6 MW, the BESS is relatively small when considered in broader power system terms,” Hillebrand said.
“Despite its size, the BESS represents a significant component of the Northern Territory power system. An equivalent asset in the national energy market would be in the order of two to three-gigawatts. It is a system‑shaping resource that materially influences frequency control, system strength and operational flexibility.”
According to Territory Generation CEO Gerhard Laubscher FIEAust EngExec, the Channel Island BESS represents more than a technical achievement.
“It’s a strategic investment in the Northern Territory’s energy future that demonstrates Territory Generation’s commitment to innovation and delivering long-term value, flexibility and resilience for its power systems,” he said.
“By transitioning some essential system services from gas to battery storage, we’re strengthening grid stability while reducing fuel use and emissions and creating a more efficient platform for the future energy mix.”
As a result of the better-than-expected performance of the Channel Island BESS, Territory Generation plans to roll out three more battery systems across the territory.
One of the future BESS projects is planned for Owen Springs Power Station in Alice Springs, with the remaining two in the Darwin‑Katherine system.
“Similar technologies are planned for future BESS projects to maintain consistency across the Territory Generation fleet,” Hillebrand said.
“Lessons from the design, construction and commissioning phases will be leveraged to inform future projects.
For more information about Territory Generation’s BESS technology, visit the website.
