Vector says it's seeing a pick-up in the number of customers choosing solar technology.
The electricity and gas lines company, which reported its half-year results last week, says about 40 percent of its revenue comes from the unregulated side of its business.
Sales in its technology arm were up 26 percent in the six months to December to $66.5 million, although much of that was driven by its smart meters.
Chief executive Simon Mackenzie says the level of interest in solar technology is starting to take off. He says customers pay a one-off upfront cost for installation and get solar panels on their roof, battery storage and all the information that's needed to see what is happening in the home.
Mr Mackenzie says there's an upfront cost of $2000, with $70 a month to pay thereafter, typically saving $30 a month on the power bill.
He says the feedback from customers has been is that it's a good solution and it's quickly installed.
Mr Mackenzie says the balance of power is shifting from utility suppliers to customers as they become more savvy about their energy use and it becomes easier to change suppliers and switch from the grid.