Franz Josef dairy farmer Graham Berry no longer receives power bills. Instead, each month the born-and-bred Coaster receives a monthly pay-cheque for the electricity he puts into the grid.
"Depending on the spot market price, it ranges from $500 to $1200 a month."
Graham milks 160 cows on a 145-hectare block of land that stretches from the main highway back to the bush-clad, Westland National Park.
He's also built a 55-kilowatt, hydro-electric scheme that uses water from a small creek in the Department of Conservation-managed park bordering his farm.
It's been running since November 2015. The Chinese-made turbine powers, the milking platform, electric fences and three houses.
Any surplus power - about 30 kilowatts per hour - goes into the national grid.
But building it wasn't without challenges.
A track needed to be cut for a pipe running from the intake, up a steep hill, to a turbine shed 1.6 kilometres away and Graham spent four years applying for permits and building the scheme.
The hydro-electric system cost him about $400,000. He reckons it will take about 12 years to pay it off.