Is solar worth it in NZ? Payback by region (2026)
Solar is the home-energy question with the most confident answers and the least agreement. The honest version, and the one both EECA and Consumer NZ publish, is that rooftop solar in New Zealand pays for itself in about seven to ten years. Where you land inside that range depends less on the brochure, and less even on your region, than on one behaviour: how much of your own generation you actually use.
If you want a number for your own roof and rate, our solar payback estimator does the maths interactively. This guide explains what drives that number - including the one deduction most solar calculators quietly get wrong.
The one number that decides it: self-consumption
A grid-tied system does two things with the power it makes. Whatever your house is using at that moment comes straight off the panels, so you avoid buying it. Anything left over is exported, and your retailer pays you a buy-back rate for it.
Those two are worth very different amounts. Avoided power is worth your variable unit rate - typically 28-38c/kWh including GST. Exported power earns a buy-back rate that across the NZ market sits around 8-17c/kWh on standard plans. So a unit you use yourself is worth roughly two to three times a unit you export.
That gap is the whole game, and it is why the households that do best out of solar are the ones consuming their own generation while the sun is up: someone home during the day, a hot water cylinder or hot water heat pump timed to heat at midday, dishwashing and laundry on a timer, or an EV charging in the driveway through the afternoon.
What solar does not offset
This is where a lot of solar maths goes astray, so it is worth being precise. Your power bill has two parts: a daily fixed charge you pay for being connected, and a variable rate for each unit you use. Solar only displaces the variable rate. The fixed charge is payable whether your panels make nothing or make a fortune, because you are still attached to the network.
That matters because the headline figure quoted in price surveys - the roughly 42c/kWh national average - is a blended number that spreads the daily charge across your usage. It is the right figure for answering "what does my power cost me overall", and the wrong one for "what is a solar unit worth". Use the blended rate in a payback calculation and you will overstate your savings by something like 15-25%. The figures below use the variable rate instead.
What a system costs
EECA's published figures put a typical installed system at about $8,500 for 3 kW and $11,500 for 5 kW, GST included. Allowing for roof complexity, inverter choice and any switchboard work, a realistic 2026 range for a family-sized 5-7 kW system is roughly $11,000-$16,000. Adding a battery is a separate decision covered below.
For generation, a reasonable NZ rule of thumb is that each 1 kW of panels produces around 1,300 kWh a year - call it a 1,200-1,450 band depending on region, orientation and shading. So a 5 kW system generates somewhere near 6,500 kWh annually, close to a whole household's use, though spread very unevenly across the seasons and the day.
Payback by region
The table below models a 5 kW system at $11,500, a household using half its generation directly, a 33c variable rate displaced and a 13c buy-back. Regions are ordered by sunshine hours from NIWA data. Treat it as indicative, not a quote.
| Region | Est. kWh/yr | Payback |
|---|---|---|
| Blenheim / Nelson | 7,250 | 6.9 yrs |
| Tauranga / Bay of Plenty | 7,000 | 7.1 yrs |
| Napier / Hawke's Bay | 6,900 | 7.2 yrs |
| Wellington | 6,900 | 7.2 yrs |
| Auckland | 6,750 | 7.4 yrs |
| Christchurch | 6,600 | 7.6 yrs |
| Central Otago / Queenstown | 6,400 | 7.8 yrs |
| Dunedin / Southland / West Coast | 5,900 | 8.5 yrs |
Two things surprise people here. Wellington does better than its reputation - it has fewer sunshine hours than Auckland but panels run more efficiently when they are cool and wind-swept, so per-kW yield holds up well. And Central Otago is not the solar champion its blue-sky summers suggest: Queenstown records fewer annual sunshine hours than Auckland or Tauranga, and its winter sun angle is poor. Sunshine hours are a proxy for yield, not a measurement of it.
Self-consumption matters more than your region
Notice how narrow that regional spread is - about a year and a half between sunny Blenheim and the deep south. Now watch what changes when the same system is used differently:
| Self-consumption | Blenheim / Nelson | Dunedin / Southland |
|---|---|---|
| 30% (out all day) | 8.3 yrs | 10.3 yrs |
| 50% (typical) | 6.9 yrs | 8.5 yrs |
| 70% (home, EV, timed hot water) | 5.9 yrs | 7.2 yrs |
A southern household that uses 70% of its generation beats a Blenheim household that uses 30% of its. That is the argument of this whole guide in one line: how you use solar matters more than where you live.
The battery question
A battery stores daytime generation for the evening, turning power you would have exported at ~13c into power you would otherwise have bought at ~33c. That is a genuine saving - it just rarely covers the battery's own cost in time. EECA puts a battery at $5,000-$15,000 on top of the panels, which for most systems roughly doubles the total spend, and batteries are typically warranted around 10 years, which is shorter than the premium takes to repay at current buy-back rates.
Where a battery does earn its keep is resilience - keeping the fridge, lights and internet alive through an outage. If that matters where you live, the value is real even when the payback maths is marginal. Just buy it with your eyes open about which of the two you are paying for.
Subsidies, and the finance that actually exists
As at July 2026 there is no operating government subsidy or rebate for household solar in New Zealand. Two support schemes have been announced as policy ahead of the November 2026 election - one offering kickstart grants and low-interest loans, another a rates-repaid home energy loan - but neither exists yet and neither can be applied for. Do not build them into your numbers.
What does exist today is bank green lending. Several major NZ banks offer low-interest or interest-free loans for solar, batteries and insulation, typically over a fixed term. For a system paying back in under a decade, cheap finance is the difference between finding $12,000 up front and paying it off out of the savings - which is, for most households, the practical question.
When solar clearly stacks up
- You are home during the day, or can shift hot water, laundry, dishwashing and EV charging into daylight - the single biggest lever.
- You are staying put for many years - payback is long and rewards patience.
- Your variable rate is high, so every self-consumed unit is worth more.
- Your roof faces roughly north with little shading.
And when it is weakest: an empty house all day exporting most of its generation, a plan to move within a few years, or a shaded, south-facing roof. In those cases the numbers stretch out well past a decade.
One caveat on buy-back rates
Buy-back rates are less comparable than they look. Some retailers quote them excluding GST and others including it, so a "12c" from one and a "12c" from another can differ by 15%. Several also offer much higher rates in narrow windows - peak-hour or winter buy-back can reach the low 20s - but these are conditioned on the season, the time of day, a smart meter, and sometimes a monthly cap. Read what the headline rate actually applies to before you let it swing your decision.
Work out your own payback
The regional figures above are averages, and your own situation can sit well outside them. Put your quoted system price, your usage, your realistic self-consumption share and your retailer's buy-back rate into the solar payback estimator - then sanity-check what you pay now with the power bill calculator.
Related guides
- EV home charging cost in NZ - the daytime load that makes solar pay faster
- Hot water heat pump cost in NZ - another way to soak up your own generation
- Electricity price per kWh in NZ - blended vs variable rates explained