Darwin big battery to displace gas generators in Northern Territory

The Northern Territory government has opened the formal tender process for its 35MW Darwin big battery that it says will displace gas generation at the same time as supporting the rollout of more solar as the territory accelerates its transition towards its 50 per cent renewable energy target.

The 35MW battery is expected to have a storage of around half an hour, meaning its principal role will be to provide essential grid services, such as frequency control, inertia and system strength, and step in to cover any impact of cloud cover on solar output, and reduce the need for gas-fired spinning reserve.

“The primary objective of the project is to displace the supply of system services from gas-fired synchronous generation, reducing operating costs and improving environmental outcomes,” the tender document says.

The tender process opened this week, with submissions due in the first week of December, after which a short list will be decided and final request for proposals due in March. The big battery, estimated to cost around $30 million, is due to be complete by mid 2022, and will be located at one of a handful of proposed sites in and around Darwin.

The Northern Territory government estimates the big battery will deliver savings of around $6 million a year – from the reduced gas generation – and so pay for itself in about five years. A similar sized battery in the Pilbara grid operated by Alinta (pictured above) is also expected to pay for itself in less than five years.

“The BESS procurement process is a huge step forward in our plan for 50 per cent renewables by 2030,” energy and renewables minister Eva Lawler said in a statement.

“We want Territorians to have access to the latest and best technology as we build a stronger and more resilient power system for Territory households and businesses. This initiative will help lower power bills while maintaining secure and reliable power for Territorians.”

The head of Territory Generation, Gerhard Laubscher, said the big battery will provide near-instantaneous response to changes in solar load, such as cloud cover.

The tender documents also make clear the Darwin battery will be required to deliver contingency and regulation frequency control, voltage control, system inertia, system strength, enable the reduction of spinning reserve, displace one of the main gas units in terms of its role for grid services, and enable more solar PV on the network.

The tender document says the project may take the form of a single large energy storage system, or an aggregation of multiple smaller energy storage systems to achieve the identified Project outcomes.

“Reliability and stability of base load power is a critical barrier in the uptake of renewable energy across Australia, and I am pleased that we are at the forefront of tackling this issue right here in the Territory,” Laubscher said.  “We are taking a collaborative approach to project planning with a number of stakeholders across Government and industry, to ensure we are maximising value to the Territory.”

The Darwin battery will be located within the Darwin-Katherine grid, one of three distinct grids in the NT.

It will be the largest battery in the territory but it will be dwarfed by the big batteries proposed by the Sun Cable project goes ahead, with plans for 10GW of large scale solar and 20GWh of battery storage, mostly to supply an undersea cable that would provide clean power to countries such as Singapore.