Treasurer Dominic Perrottet said the money would be spent over the next four years and would fuel the delivery of cheap, reliable electricity for homes and businesses across the state.

Under the electricity infrastructure roadmap, the government plans to bring online 12 gigawatts of renewable energy and two gigawatts of storage by 2030.

"The roadmap is expected to attract $32 billion of investment over the next decade and create thousands of jobs," Mr Perrottet said in a statement on Thursday.

"This investment is consistent with key recommendations of the Productivity Commissioner Peter Achterstraat's recently released white paper, which highlights the importance of a reliable, sustainable and productive supply of energy for NSW."

Energy Minister Matt Kean said the funding package was the biggest NSW government investment in large-scale renewable energy in the state's history.

"We have the most ambitious renewable energy policy in the country," he said.

"With four of our five coal-fired power stations due to reach the end of their technical lives in the next 15 years, we are on the clock to replace them before they close to keep the lights on and prices down."

He said the roadmap strategy would deliver NSW families and businesses "some of the cheapest electricity in the OECD and will set the state up for success in a low-carbon world".

The funding will ensure transmission upgrades in the Central West-Orana Renewable Energy Zone were shovel-ready by the end of 2022.

The budget funding boost builds on more than $110 million of existing funding commitments, including $40 million for the Central West-Orana REZ and $79 million for the New England REZ.

The NSW budget will be handed down on Tuesday.

Australian Associated Press