Why aren't we making the switch to solar energy?

By Rebekah White

Solar potential maps of New Zealand show that we’ve got a lot of it. Potential, that is.

When it comes to generating energy solar power, New Zealand is flatlining as other countries are skyrocketing.

That’s despite multiple reports and studies showing that solar energy could cut the average household’s annual power bills by at least $1000 and provide the country with more energy security.

Farmers who install solar could halve their energy costs while also making some income selling electricity back into the grid, says the Energy Efficiency and Conservation Authority.

Next year, solar is predicted to overtake coal as the world’s biggest electricity-generation source.

But in New Zealand, the up-front expense of installation remains a hurdle – the average household solar system costs $16,500.

While numerous national or state governments overseas offer subsidies, rebates, feed-in tariffs, tax credits, or other incentives for households to install solar, New Zealand stands out for its lack of support.

However, there’s also perhaps a psychological obstacle at play, suggests Ralph Cooney, a professor emeritus, chemical sciences, at the University of Auckland.

People don’t see solar as a capital investment

When considering whether to invest in rooftop solar, people usually focus on how long the payback period will be, says Cooney: how many years it’ll take for the savings on power bills to compensate for the cost of installation.

That skips an important aspect of switching to solar energy, says Cooney.

“New Zealanders tend to view rooftop solar as, ‘It has to pay for itself’,” he says.

“Without looking at the fact that you’ve actually improved the capital value of the property.”

Instead, says Cooney, the addition of solar should be regarded the same as adding other amenities to a property, like a deck. No one expects a deck to pay for itself.

“But you would say, ‘I’ve improved the property, so when I sell the property, I’ll get the value of the deck.’

"Now, people don’t think of solar in those same terms, but they should do.

"It’s a capital improvement on the property that actually is attractive to a new buyer.”

Earlier this month, the financial journalist Frances Cook calculated that her household’s switch to solar energy has been an investment with a higher rate of return than the stock market – without accounting for future power-bill savings after the payback period.

The biggest savings involve combining rooftop solar with electric vehicle use, says Cooney: “It enables EV owners to drive their car free of fuel costs.”

Up-front cost is still a barrier 

Across the ditch, Australia is a world leader in solar energy, with around a third of all households in the country having some form of solar generation.

While Australia has a great deal more sunlight hours than New Zealand, that isn’t entirely the reason it made the switch so quickly to solar, says Cooney.

“The government there has provided incentives for residential solar in a way that the New Zealand government never did.”

Not all Australia’s financial incentives remain, but the country still has a rebate for solar installation.

Whereas here, solar subsidies are limited to a handful of community projects and schools.

Until last October, adding rooftop solar to a New Zealand residential house required building consent.

Permitting requirements remain an obstacle to on-farm solar projects, says Federated Farmers.

A survey by the organisation found that 70 percent of respondents were interested in installing solar on their farm.

Last July, Federated Farmers called for streamlining regulations, the rules and costs of which vary wildly depending on the region.

In most areas, farmers must obtain resource consent – and in Canterbury, farmers also must obtain a stormwater consent for rain dripping off the panels.

Solar can help with energy security

“Solar and wind and some other forms of renewables can be set up so that they don’t require the same extensive massive grids that we’ve had in the past,” says Cooney.

That’s something the Pacific islands are beginning to capitalise on, with a focus on solar over other renewables.

“They’re very highly motivated to move into renewables, and they are reluctant to move into wind because of the risk of cyclones destroying the infrastructure.”

Samoa was the first country in the Pacific to install battery energy storage systems, in conjunction with a large solar farm across the road from the airport.

It now saves the airport hundreds of thousands of dollars per year in energy costs.

Here, an increase in solar generation could help retain more water in the country’s hydro lakes in dry years: Cooney wants to see an increase in utility solar, which is distributed via the grid.

Currently eight solar farms are operational in New Zealand, with another nine under construction.

On a household level, stored solar energy can provide security during weather events when mains power is cut as during Cyclone Gabrielle, when more than 200,000 households lost power for up to a week.

That security increases when households also own an EV – their substantial battery capacity can be used to power a home if mains power is cut or solar generation lags.

“It is an interesting little bit of insurance, if you like, for a household,” says Cooney.

New Zealand isn’t the sunniest, but that’s no obstacle

“We just don’t get the solar energy that some other places get,” says Cooney.

“The places around the world that scream out saying, ‘This is a great place for solar’, are places like Western Australia and North Africa. Those countries are really going ahead with it.”

That shouldn’t hold us back, says Cooney.

For a long time, the world leader in solar power was Germany, which is hardly known for its sunshine hours.

Instead, the government provided financial incentives, and the public took them up.

Now, around a fifth of Germany’s electricity comes from solar, and its success paved the way for Australia’s strategy and energy transition.

The Solar Potential Map for Auckland, created by three University of Auckland researchers, uses LIDAR data to indicate how much electricity could be generated on city rooftops. The answer is: plenty.

Non-leafy suburbs have the solar advantage – as those trees provide shade – with areas in the southeast of the city receiving the highest ratings for solar generation.

Paradoxically, solar uptake in New Zealand doesn’t always coincide with the sunniest spots.

While the country’s sunniest town in 2025 was New Plymouth (again), Taranaki lags at 17th out of 39 regions for solar uptake.

“Solar’s the cheapest energy we’ve got,” says Cooney. “It’s provided for free by nature. So why wouldn’t we actually embrace it?”

The world is facing unprecedented environmental challenges. Planetary Solutions, an initiative of the Sustainability Hub at Waipapa Taumata Rau, University of Auckland, and Newsroom, explores these issues – and the practical ways we can all be part of the solution.