Household wealth, home ownership rates and the ‘neighbourhood effect’ are driving rooftop solar rates in the absence of widespread incentives, advocates say.
An RNZ analysis of Electricity Authority data has found that Wānaka and Pāpāmoa Beach have the highest numbers of household solar installations in the country, generating about 50 percent more energy than anywhere else in the country.
Wānaka also had one of the highest rates of installations, with 17 percent of houses boasting some level of solar generation.
Earlier this year, New Zealand hit a milestone, with enough solar energy capacity now installed to generate a gigawatt of electricity – about half of it on people’s homes.
Across New Zealand, the installation rate on residential dwellings was just four percent – far behind Australia, where incentives have driven uptake over the last 15 years to more than a third of all households.
Most political parties have now unveiled election policies to incentivise uptake here, including low-cost loans and direct subsidies to low- and middle-income households.
Rewiring Aotearoa chief executive Mike Casey said, to date, solar had largely been limited to those with the financial means to pay for their own installation or access finance, via a green loan.
He was therefore unsurprised by the suburbs and towns at the top of the list.
“They’re very wealthy suburbs that have access to that finance. They own their own home, they have enough equity in their home, they have big enough mortgages that the banks will approve those loans.”
RNZ’s analysis showed homeownership, rather than household income, was a stronger driver of uptake.
Casey said, again, that was down to homeowners with current mortgages being able to access no-interest or very low-interest green loans through their bank.
“That enables them to put $20,000 worth of hardware on their rooftop and pay that back over time.”
Research in Australia has found that, once solar was widely available, middle-income households adopted the technology with the most gusto,
A 2024 Australian Climate Council report said the lowest-income households may still struggle with the upfront cost and the highest-income households had less incentive to reduce their power bills.
Casey said that pattern would likely repeat in New Zealand.
“They will probably be dual-income households with really big mortgages, because that is where they care about the savings.”
One factor drove solar uptake more than anything else, he said.
“The No.1 reason that you install solar panels on your rooftop is because your neighbour did.”
That positive feedback loop was kicked off by early adopters, who “will then not shut up about their rooftop solar and the amount of savings that they’re making”, Casey said.
Energy Efficiency and Conservation Authority lead adviser Gareth Gretton said those early adopters could provide recommendations and encouragement to interested neighbours, in turn sending “a bit of a ripple through the area”.
“So a neighborhood that happened to be just slightly ahead in adopting solar a few years ago, now becomes really quite high rates of adoption.”
New Plymouth solar installer Brad Lynch said his Solar One business had seen that effect unfold in reality.
“We’ve got a street in one of the suburbs here in New Plymouth that we’ve just about renamed to Solar One Street, because we’ve got about nine properties on the one street that started with one [house] two years ago and they’ve just kept going from there.”
His customers no longer had a particular demographic and what they were installing was also shifting dramatically, he said.
“Thirty percent of our solar systems had batteries attached to them only 18 months ago and now we’re at 85 percent battery attachment.”
Wānaka resident Adrian Taylor and wife Janine upgraded their solar system six months ago to include a battery, after finding they couldn’t use all the power they generated during the day.
“The great thing is now that excess we’re creating during the day sits in the battery and we can use it in the evening,” he said.
The couple’s power bills had reduced “significantly” to the point that they had received a credit a couple of times since upgrading.
They first installed solar seven years ago.
“There was the hope to reduce our electricity costs and there was a kind of sense that we were doing the right thing by the environment,” Taylor said.
He was surprised Wānaka had higher numbers of solar panels than most other areas, saying his house was still the only one on their small street to install them.
“I really don’t know [why], the climate here is so good for it – it seems just like such a no-brainer to me.”
The architectural designer advised all his clients to consider installing solar, especially if they were building a new house.
“At the very least, put in place bits and pieces to make it easier to do it later – running conduits or even draw wires, and things like that, if you don’t think your budget will enable you to do it at the moment.”
Many of the areas RNZ found had the highest rates were also locations with high rates of developments or newer builds, including north Cambridge, Rolleston, and the outskirts of Wānaka and Queenstown.
Mike Casey said there was still not enough solar being installed at the time houses were built.
“That is something that we need to chase in New Zealand, because… while the person’s already on your roof laying the tin, they might as well be laying the solar panels as well.”
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