The bidding war among NSW political parties over solar panels has been joined by the Greens who want photovoltaic systems and batteries to be made compulsory for all new dwellings.

The Greens would also introduce a $2000 rebate for the introduction of panels plus storage for half a million homes as part of $1.25 billion boost over four years for the sector.

Cleaning up: solar PV demand is soaring - and political parties are seeking to accelerate the take-up in NSW. Credit:Jason South

All public housing and government buildings would get panels too at a cost of $250 million, with 110,000 public housing tenants in line to receive electricity rebates, according to the Greens' policy aimed at the March 23 state election.

“It is negligent that in 2019 we have over 70,000 new dwellings in NSW every year and no requirement for solar panels on these developments," Cate Faehrmann, the Greens environment spokeswoman, said. Owners of new dwellings would pay into a renewable energy offset scheme as an alternative to adding panels or storage.

The Greens' policy follows Labor's launch on Saturday of its plan to support 500,000 households get solar, with a rebate capped at $2200 for households with annual income of $180,000 or less.

The Berejiklian government followed a day later with the release of a scheme offering no-interest loans for solar energy and batteries for as many as 300,000 owner-occupied households.

For those living in flats or renting, the Greens would set up an offset scheme to buy credits for solar arrays on their building or offsite. Some 20 per cent of all private dwellings in the state are apartments, while about 32 per cent of residents are renting - people who are currently "locked out of the benefits of roof top solar," the Greens said.