The three turbines at Port Durham Windfarm can deliver more power than the current peak demand, making it possible for the Chatham Islands to run entirely on renewable energy.
The island uses diesel generators which are vulnerable to supply chain disruptions from an ageing ship and fuel price fluctuations.
It means electricity prices on the Chatham Island are about four times higher than the New Zealand average.
Associate Minister for Regional Development Mark Patterson said the wind farm meant the Chatham Islands would have a more stable and reliable electricity supply as well as reducing emissions.
"This initiative means households and businesses on the Chathams will benefit from significantly lower electricity costs, with expected savings of around 40 cents per kiloWatt hour," he said.
Diesel use was expected to be cut by up to 68 percent, saving approximately $1.2 million each year, he said.
It would more than halve carbon emissions per person from 3.34 tonnes to 1.37 tonnes a year, Patterson said.
The wind farm will be officially opened on Thursday by Patterson after being built in two years on the remote archipelago.
It received a $10 million grant from the previous government's Climate Emergency Response Fund in 2023.
It also received a $500,000 grant from the Provincial Growth Fund.
The wind farm includes three wind turbines, a storage battery and other infrastructure.
