Mr Barr will on Wednesday announce what he says is one of the party's biggest commitments in the election campaign so far.

The battery network, to be delivered over five years at a cost to taxpayers of $100 million, would have a battery storage of at least 250MW.

"This major Canberra project will be significantly bigger than the Hornsdale Battery in South Australia, which is being upgraded to hold 150MW of storage," Mr Barr said.

"ACT Labor wants Canberra to become a globally recognised centre for renewable energy innovation and investment.

"It is a significant project that aims to provide a nation-leading battery storage facility."

Mr Barr said it would create lower electricity prices and a more stable and resilient power grid.

"The global battery storage market is predicted to be worth $400 billion by 2030 and the ACT is an ideal launching pad for national and international businesses wanting to get a head start in this exciting emerging industry," he said.

"We want to store that energy and provide it back into the grid when Canberra households and businesses need it."

Unlike the Hornsdale battery, Labor's proposal would involve a network of batteries built around the city, instead of a single battery.

"In a distributed model we can locate our batteries in a number of different locations," Mr Barr said.

"They tend to work best when located near major solar farms ... or significant pieces of government infrastructure."

Mr Barr said it would address network constraints and allow more Canberrans to have solar. He said low-cost energy storage was the missing link in the transition to a 100 per cent national electricity market.

Labor says it would create an expert team to lead procurement and determine suitable sites for the batteries.

Part of the network will include the two big batteries announced last month as part of the government's reverse auction scheme.

They are currently anticipated to have a joint storage capacity of 60MW, but Mr Barr says the government may work with the providers to increase this.

The assets would likely be a mix of public and private ownership. Mr Barr said part of the stored energy would be sold back into the grid, while some would be reserved for blackouts and brownouts.

He pointed to the Hornsdale project, which earned $1 million over two days in late 2019 when the spot price jumped to more than $14,000 per megawatt hour.

"We want to have that capacity, but want to make sure we can reserve part to meet the circumstances of a load shedding event," he said.