Darwin to treble big battery plans as rooftop PV makes its mark on Top End grid

The Northern Territory government is to dramatically expand the amount of big battery capacity as it looks to deal with an increasing share of solar in the Top End grid.

The government this week announced a second “big battery” for the Darwin-Katherine grid, taking the capacity from 35 MW in the soon to be completed first battery to 105 MW.

The storage duration was not cited, but is likely to be consistent with the one hour storage in the initial project. Unlike the first big battery, which has been built at one site, the new battery system is likely to be spread around the grid to add resilience to the network.

The $45 million DK BESS 1 – it stands for the Darwin-Katherine Battery Energy Storage System – is designed to reduce the amount of gas generation it has spinning in reserve, and will save at least $9.8 million a year in fuel costs and paying for itself within five years of commissioning.

The government said in its release this week that all 192 batteries, each weighing 3.5 tonnes, had been installed for the 35 MW/ 35 MWh installation, although it did say much the same thing in May last year.

Renew Economy understands that testing – and making it compatible with the evolving code of the local grid – is taking time, as it has done with other big battery projects in the country’s main grid. It is the first big battery to be installed in the NT’s main system.

The NT government says expressions of interest for the second Darwin battery project are already being assessed and preferred applicants will be asked to put forward a detail proposal. It is looking for another 70 MW of capacity.

The government says the second battery will deliver more fuel savings, and enable more solar capacity by providing frequency and voltage control services. Commissioning is targeted from 2026.

“The DK BESS and DK BESS 2 are an important part of our transition to a renewable energy future,” chief minister Eva Lawler said in a statement.

“We are able to invest in our power grid because we own our assets like Territory Generation, Jacana and Power and Water. By owning our assets we can keep power prices low. Battery technology will play a significant role in our target of reaching 50 per cent renewable energy consumption by 2030.”

Territory Generation CEO Gerhard Laubscher said the installation, construction and pre-commissioning of the first Darwin battery at the Channel Island facility is now complete, and is moving towards full-scale commissioning

“Adding more battery energy storage systems to Territory Generation’s portfolio will not only enable more renewables and efficient generation dispatch throughout the energy transition, but also fosters the evolution of technological innovations and further supports grid resilience,” he said in a statement.

The first battery has been delivered by Hitachi Energy. “We would welcome the opportunity to continue support the Northern Territory’s energy transition should it arise,” its head of grid edge solutions Maxine Ghavi said in a statement.