By Luke Costin in Sydney

A contentious $4.8 billion project crucial to expanding Snowy Hydro and other renewable energy projects has gained federal approval.

The HumeLink overhead transmission line in southern NSW will boost the capability of the National Electricity Market but has drawn criticism from farmers, local communities and environment groups.

The operator’s battle for grassroots support and refusal of underground wires through prime farmland and Kosciuszko National Park has been closely watched amid a need to build 10,000km of transmission lines nationally to support the emissions-focused transformation of the electricity grid.

HumeLink will construct 365km of new 500-kilovolt high-voltage transmission infrastructure between Wagga Wagga, Bannaby and Maragle, increasing transfer capacity between southern NSW and greater Sydney.

Its most important role is connecting the Snowy pumped-hydro battery project to the grid, adding 2200MW of on-demand energy into the grid, similar to the capacity of a large coal-fired power station such as Liddell.

The project was subject to strict conditions to protect nature including limits on land clearing and minimising impacts on hollow-bearing trees and threatened species, the government said.

Most of the new transmission lines will lie within existing transmission corridors which minimises clearing, it said.

Environment Minister Tanya Plibersek used the approval as an opportunity to slam the opposition’s nuclear-centric power plan.

“Labor is getting on with the job of transforming Australia into a renewable energy superpower while Peter Dutton and David Littleproud’s risky nuclear plan is threatening investment in renewables,” she said.

“I’ve approved almost 70 renewable energy projects – enough to power more than seven million Australian homes.”

A NSW parliamentary inquiry in 2023 examined the significant community support for constructing high-voltage transmission lines underground, including fears overground lines would exacerbate the area’s already-high bushfire risk.

“You’re asking this community to bear the brunt of this overhead monstrosity so people in metropolitan areas can have cheaper power bills,” Snowy Valleys mayor Ian Chaffey told the inquiry at the time.

But operator Transgrid had estimated a subterranean line would cost up to $11.5 billion and would take too long.