Several Ngāruahine hapū will be in the Court of Appeal with Greenpeace on Tuesday to seek tighter controls on a wind-powered hydrogen plant in South Taranaki.
Hiringa Energy wants to build four 206-metre tall wind turbines at Kāpuni, powering a plant to make hydrogen.
Hiringa Energy says the hydrogen will initially be an ingredient to make urea at the Ballance fertiliser factory, and then over five years use will shift to instead fuel heavy vehicles - a carbon-free alternative to diesel.
But the hapū and Greenpeace say the resource consent conditions do nothing to stop Hiringa using the hydrogen to make nitrogen fertiliser for decades, and the court needs to rule that out.
They oppose current levels of synthetic urea fertiliser use because of nitrogen pollution in rivers and drinking water.
Included in the appeal are the hapū of Ōkahu-Inuāwai me ētehi atu, Ngāti Tū, Ngāti Tamāhuroatitahi, Ngāti Haua and Kanihi Umutahi me ētehi atu.
The chair of Ōkahu-Inuāwai me ētehi atu, John Hooker, said the project would damage the hapū's relationship with their traditional lands, waterways and mountain.
"For decades, our people have fought to exert their kaitiakitanga and tikanga to safeguard our maunga, awa, whenua and moana so that the next generation don't have to. When does it stop?"
The hapū's taiao (environment) lead, Mere Brooks, was skeptical about a project wrapped in a Māori name.
"We all want to see a transition to green energy and we take our role as kaitiaki (stewards) seriously. But it's easy to start getting cynical when greenwashed projects with a brown-washed title from industry like this get through."
A simulated view of the wind turbine towers from Te Aroha Marae.
In December Balance's chief executive Mark Wynne said the hydrogen project would not increase urea use in New Zealand.
Urea from the project would replace up to 7000 tonnes of imported fertiliser, most produced using coal and gas in the Middle East and Asia, he said.
This would offset up to 12,500 tonnes of carbon emissions, the equivalent of 4700 cars.
Hiringa co-founder and chief executive Andrew Clennett said the Kāpuni project provided an economic way to phase in hydrogen through a bumpy start-up period.
"While we build our refuelling network and… the numbers of zero-emission vehicles on the road, we need an economic way of building that infrastructure and providing a flexible supply, as during the early establishment phases there won't be a constant stream of vehicles arriving to fuel."
Opinions have varied amongst the six hapū of Ngāruahine: Ngāti Manuhiakai and Ngāti Tū, which hold mana whenua closest to the project, gave conditional support - but Ngāti Tū has now joined the appeal.
A cultural impact assessment by the iwi organisation Te Korowai o Ngāruahine gave conditional support, so long as the windmills were removed at the end of their useful life - a maximum of 35 years.
The four giant wind turbines would be the tallest structures in Taranaki, built in what Ngāruahine considers a highly-valued cultural landscape, impacting on its relationship with Taranaki Maunga.
The consenting panel agreed that future replacement turbines must be built on the coastal side of State Highway 45, far from the mountain, on a site chosen in collaboration with hapū.
A new Te Korowai board unsuccessfully tried to overturn the consent in the High Court, which found the consenting panel had properly considered the Ngāruahine cultural landscape.
Local Democracy Reporting is Public Interest Journalism funded through NZ On Air