The Green Party wants to set up a new government-owned energy company called KiwiPower. It would invest in renewable energy like solar and wind, and the party says it would be paid for with $980 million over four years from a new tax on the very wealthy.

Co-leaders Chlöe Swarbrick and Marama Davidson launched the plan at the Dunedin Gasworks Museum on Monday. The museum is on the site of the country's first and last coal gas plant. Swarbrick said the venue was chosen on purpose: gas belongs in a museum, not in modern policy (RNZ).

KiwiPower would get $100 million a year to run and $142 million a year to invest in new projects. Swarbrick said the money would come from the Greens' proposed taxes on wealth, corporations, and inheritance, making the super-rich and big companies pay their fair share.

Swarbrick said 200,000 households cannot afford to heat their homes. She also said four big power companies control more than 85 percent of the market. The plan would use public money to compete with those companies rather than trying to regulate them. People and businesses with solar panels would also get a fair price for extra electricity they sell back to the grid.

The solar part of the plan is broad. Homeowners could get zero-interest loans to install solar panels and batteries. A simpler type of solar that plugs into a normal wall socket would be made legal. Renters would get the right to put up solar panels and landlords could not unreasonably stop them. Solar would go on more than half of all public housing within four years, at a cost of $460 million.

An existing government programme called Warmer Kiwi Homes, which helps people insulate and heat their houses, would get a big boost. The Greens want to spend $969.8 million over four years to fund 50,000 more home upgrades.

The plan also includes $200 million for community energy projects, paid for by taking subsidies away from fossil fuel companies. Another $80 million would go to renewable energy for Māori housing. Davidson said tangata whenua are two to three times more likely to struggle to pay power bills, and the funding is a targeted response to that.

Altogether, the policy would cost more than $2.6 billion over four years. That includes KiwiPower at $980 million, public housing solar at $460 million, Warmer Kiwi Homes at $969.8 million, community energy at $200 million, and Māori housing at $80 million. All of it depends on the Greens' proposed taxes actually raising that money.

The broader context is that the Greens are framing KiwiPower as both a way to create jobs and industry and a way to lower living costs. Setting up a new government-owned energy company is a big change. The last time the government made a major change to who owns electricity was in the 1980s under the fourth Labour government. Since then, governments have mostly worked within that system rather than creating new public entities. Whether a future government would agree to create a new state-owned energy company, and whether the proposed taxes would raise enough money, are questions that will come up in any coalition talks.

The venue, the messaging, and the size of the spending all point to a party that wants energy to be a major election issue. Swarbrick's line about gas belonging in a museum ties the plan to the wider debate about phasing out fossil fuels. Ring-fencing $80 million for Māori housing and giving renters solar rights signals the party sees energy hardship as a fairness issue, not just a climate one. How much of this plan survives contact with a coalition partner, or with Treasury checking the numbers, is the real test ahead.