Modelling done by RepuTex for Greenpeace Australia has supported the NSW government's renewable energy plan over the federal government's gas push.

NSW this week passed legislation cementing its energy plan, which involves replacing outgoing coal-fired power stations with renewable zones across the state.

Four of NSW's five coal-fired power stations are due to close within 15 years, with AGL's Liddell the first to shut over 2022 to 2023.

The crucial time period concerning authorities is between Liddell closing in April 2023 and other sources such as HumeLink and Snowy Hydro 2.0 coming online in 2025.

Federal authorities want government-owned Snowy Hydro to build a gas plant if the private sector doesn't come up with a solution.

AGL is eyeing large-scale batteries at the Liddell site.

The analysis looked at scenarios where the Liddell power gap is filled by gas and where it is replaced by zero-emissions technologies such as battery storage, virtual power plants and demand response.

The zero-emissions option with fast charging and generation capacity is forecast to improve reliability and lower wholesale electricity prices in the two-year gap period.

The gas scenario is also estimated to reduce wholesale prices, but not by as much as the zero-emissions option.

Gas is also forecast to increase reliability and reduce maximum prices, but the return on investment in new plants could depend on other coal-fired plants retiring.

The analysis says battery capacity is faster, more flexible and precise in responding to peak pricing and volatility.

It comes as the Clean Energy Finance Corporation announces $135 million to help connect Snowy 2.0 to the national electricity grid, to supply power.

Australian Associated Press