A $32 million battery near Albury will be the first in Australia to be charged with hydro power following approval from the NSW government.
Meanwhile, the world's largest grid-scale battery, with capacity eight times greater than the grid-scale battery in South Australia, will be built in the Hunter Valley.
The dual announcements on Friday promise to inject cleaner energy into the energy grid in NSW.
The Albury battery will be charged by the nearby Hume Hydro Power Station, which presently powers 40,000 homes.
The battery will dispatch energy to the grid during times of peak demand and boost grid stability, NSW Minister for Planning and Public Spaces Rob Stokes said in a statement on Friday.
"Not only does it supply clean and reliable energy, it provides jobs and investment for the local area," Mr Stokes said.
The government claims the construction of the Albury battery, which is expected to start later this year, will create 40 jobs.
Minister for Energy and the Environment Matt Kean said NSW had some of the best hydro opportunities in the world.
"As renewable energy becomes a greater part of our energy mix, projects like this will help to support the continued growth of our economy by delivering a modern, cheap and reliable energy grid for the people of NSW," Mr Kean said.
In the Hunter Valley, CEP.Energy will build a grid-scale battery powered by solar.
The battery's capacity will be up to 1200 megawatts, the company says.
It would be the largest grid-scale battery in the world, with potential capacity up to eight times greater than the Tesla big battery in Hornsdale, South Australia.
Former NSW premier Morris Iemma, who chairs the company, said big batteries "will play a major role in filling the gaps left by the gradual retirement of coal and gas-fired generation assets, including the nearby Liddell Power Station".
"The clean energy roadmap laid out by the NSW government has provided the market with the confidence to invest in renewable generation supported by large battery storage," Mr Iemma said in a statement.
CEP.Energy chief executive Peter Wright said the site of the proposed battery, at Kurri Kurri, was one of the top locations in Australia for reliable and efficient grid connection because it was zoned for heavy industrial use and near existing substations.
Construction is projected to start in 2022 and the battery will start operating the following year.