For most New Zealand homes, yes, solar is worth it, typically paying for itself in 7 to 10 years and then generating close to free power for another 15 or more. Whether that's true for your house comes down to three things:
- How much of your own generation you'll actually use during the day.
- Which way your roof faces.
- How much you currently pay for power.
If those three run against you, the answer for your house can flip to "not yet," a real outcome covered later in this guide.
Read this page for the framework, then use the Easy Solar app to turn it into a number built around your own roof and usage.
What does solar cost in NZ?
Most homes pay $8,500 to $20,000 fully installed for rooftop solar, with a battery adding another $5,000 to $15,000 on top. As panels have got more efficient for less money, the average new system has grown to around 8 kW of inverter capacity, carrying roughly 9.5 to 10 kW of panels, which typically lands the total near $18,000 to $19,000, GST included.
That's the ballpark. Exactly where your house sits in it depends on roof size and access, panel and inverter quality, and whether a battery's in the mix.
One cost most quotes leave out: the inverter usually needs replacing once over the panels' life, at roughly $2,500 to $3,500 depending on system size (premium and hybrid units run higher), so it belongs in the budget even though it's a decade or more away.
For the full breakdown, including a fair-quote checklist and how financing works, read how much solar panels cost in NZ. The rest of this page is about whether that cost is worth paying.
What will you actually save each year?
A typical 5 kW system saves the average NZ home $1,000 to $1,500 a year, and that floor holds regardless of region: EECA's regional figures put the lowest-saving region (Southland) at $1,047 a year and the highest (Marlborough) at $1,467, both on the same size system.
Where you land in that range comes down to one lever more than any other: how much of your own generation you actually use as it's made. Power exported to the grid earns a buy-back rate that's always lower than the retail price you'd otherwise pay for the same electricity, and that buy-back rate is expected to keep falling as more solar comes onto the grid, the way it has in Australia,1 so this lever gets more decisive over time, not less.
A home that's occupied during the day, or that can shift a pool pump, hot water cylinder or EV charging into daylight hours, uses far more of what it makes than one that's empty from 8 till 6.
Put another way: your own solar generation costs about 10 to 12 cents per kWh over the system's life, using its cost per kWh (the Levelised Cost of Electricity, or LCOE), against the ~31 cents per unit you'd otherwise pay the grid. That 31 cents is the volume rate, the only part of your bill solar offsets (the daily fixed connection charge carries on regardless), so it's the honest comparison, and solar still comes in at about a third of it.
Work out your exact figure, based on your roof and region, with the solar LCOE calculator.
What's a realistic payback period?
A well-matched system pays for itself in 7 to 10 years, assuming average-to- good daytime use, electric heating and hot water, and a system sized to your actual consumption instead of your roof space. Panels are warrantied for 25 to 30 years, so on that timeline you're getting 15 to 18 years of essentially free power after the system has paid for itself.
That range moves on real, identifiable variables. The single biggest one is your current power price: the more you currently pay per kWh, the more each unit of self-generated power is worth, so the faster the system pays back. A household on a cheap plan and a household on an expensive one, running identical systems, will land at clearly different points inside that 7 to 10-year window.
Region moves it too. Put the EECA regional savings figures from above against a typical 5 kW install and Marlborough pays back in about 8 years while Southland takes closer to 11, with the rest of the country in between, driven by the same two inputs: sunshine hours and local power prices. Shifting usage into daylight hours, and matching system size to actual consumption, both pull payback forward.
On the other end, EECA's own figures show payback stretching to 10 to 12 years in weaker-fit circumstances, still a viable system, just a slower one.
Adding a battery lengthens payback further (see below); EECA's stated 7 to 10-year figure also doesn't account for interest on borrowed money or foregone interest on cash spent, so a financed system's true break-even point sits a little later than the headline number.
Financing cuts the other way too. Because the repayments spread over decades while the savings start immediately, a homeowner who folds the system into their mortgage (or a bank's green top-up loan) can come out ahead from day one: the repayments plus the smaller power bill can total less than the old power bill did, and modelling at 5.5% interest shows a financed system still netting tens of thousands of dollars over its lifetime.1
The trade-offs are real: you pay more interest overall than buying outright, and the route only exists if you have the mortgage headroom to borrow against.
Solar vs investing the money elsewhere
Solar isn't the only place that money could go. On this guide's own figures, a right-sized 5 kW system costing around $11,500 and saving $1,000 to $1,500 a year works out to an effective annual return of roughly 9 to 13%, and it's tax-free: every dollar of power it displaces is a dollar you keep, with no income tax to pay on it.
The catch is the word right-sized: the return holds when the system matches your consumption. Go bigger than your household can use (today's typical install runs $18,000 to $19,000 for around 10 kW) and more of the extra generation leaves at the low buy-back rate, dragging the return down, unless daytime use or an EV soaks it up.
Either way, that's a solid number against a term deposit or a typical balanced fund. A good year in the share market can still beat it, and this comparison doesn't promise solar wins every time. It shows a baseline return that's stronger than most people assume before they run the numbers.
Unlike a managed fund, the return isn't fully liquid. You can't cash out a system early the way you'd sell shares, and it depends on the assumptions above holding: you use a decent share of what you generate, and your power price doesn't fall.
But it also carries something a term deposit or index fund never will: it caps your exposure to rising power prices for 25 years, and it keeps the lights on in an outage if you pair it with the right setup. That value doesn't show up on a spreadsheet, which is why the comparison isn't as simple as "which one returns more."
When solar isn't worth it (yet)
Solar genuinely isn't worth it yet for some houses.
- Roof faces north, northeast or northwest without heavy shade
- Someone is home during the day, or usage can shift to daylight
- You're staying put for more than a few years
- Roof is south-facing or heavily shaded
- Out all day, no plan to shift usage or add a battery
- You plan to sell within 2 to 3 years
- Power bills are already small
Orientation matters more than most people expect:
| Roof orientation | Generation vs north-facing |
|---|---|
| North | The benchmark |
| Northeast / northwest | ~10% less |
| East / west | ~20% less |
| South | Weakest by a wide margin; no NZ study puts an exact number on it |
The short test for a good-fit roof: pitched, not flat; clear, not shaded; facing somewhere north rather than south.
Shade also changes over time. A sapling or hedge that leaves a roof completely clear today can grow tall enough within ~5 years to throw shadow across half the array, so it pays to picture the sightlines a decade or two ahead, as well as on install day.
Low daytime occupancy is a standalone disqualifier, independent of the roof. The classic case is the modern commuter household: out from 8 till 6, home only at night, exporting most of what it generates at a buy-back rate well below what it pays to import power after dark. That doesn't rule solar out entirely (a battery or shifted usage can still make the numbers work, see below) but it does mean the plain, panels-only case is much weaker.
Selling soon changes the maths directly. Because typical payback is 7 to 10 years, a household planning to sell within roughly 2 to 3 years won't recoup the system's cost through bill savings before the sale. Resale value (below) offsets part of that, but only part, well short of the full cost, so "I'm moving soon" is a solid reason to hold off on its own merits.
Most of these aren't dealbreakers forever. Shade gets cut back, a flat roof takes tilt frames that point the panels north, a commuter household adds a battery or an EV that shifts usage home, a "moving soon" plan changes. (A south-facing pitch is the exception: that one really is permanent.)
They're reasons to wait, or to run the numbers properly before committing, which is exactly what a personalised assessment is for.
Does a battery change the answer?
On pure payback, not yet. A battery typically lengthens payback rather than shortening it, because it's a real added cost ($5,000 to $15,000) with no extra generation to show for it.
The maths is straightforward: every stored unit you use after dark earns you the gap between the retail rate you avoid (~31 cents) and the buy-back you gave up (~16 cents), about 15 cents per kWh. Even a battery cycled hard every day banks only around $500 a year on that gap, a slow road to repaying a $5,000-plus price tag. That's expected to improve as battery prices keep falling and more retailers move to time-of-use plans, which widen the price gaps a battery earns its keep on.
If your main goal is simply using more of what you generate, and backup power isn't the priority, a cheaper option often gets you most of the way there: a hot water cylinder timer or solar diverter banks surplus daytime generation as hot water, at a fraction of a battery's cost.
None of this is slowing buyers down. Just over half of new residential solar systems in New Zealand now go in with a battery, up from around 30% in 2024, according to Electricity Authority installation data (June 2026). Plenty of households are clearly buying one for reasons beyond the return.
Those reasons are real. A battery is a genuine fit if your household uses a lot of power after dark and can't realistically shift that into daylight hours (heavy evening or overnight loads like a heat pump or EV charging), if you want backup power through an outage, especially somewhere prone to storms or long line faults, or if maximum self-sufficiency matters to you more than the fastest payback.
One important catch on backup: a standard grid-tied system shuts off in a blackout by design, for lineworker safety, even in full sun. Getting real outage power needs a hybrid or island-capable inverter on top of the panels.
Do solar panels add value to your home?
Yes, modestly and verifiably. A 2026 peer-reviewed New Zealand study, Power in the pitch (Matthews & Harland, matching 79,944 property listings to actual sales, 892 of them solar), found homes with solar sold for an average 1.34% price premium over comparable non-solar homes, with no measurable difference in how long they took to sell.
If that sounds modest next to figures you might have seen quoted overseas, that's because it is, and the study's own authors explain why: the premium in Australia runs roughly 1.9 to 3.2%, and in the US closer to 4%, a gap the researchers put down to New Zealand's comparatively cheap electricity, lower solar uptake, weaker export incentives and lower battery uptake than those markets.
With power prices rising and batteries now going into over half of new installs, the conditions the researchers blame for the modest premium are shifting in solar's favour, so 1.34% reads more like a floor than a ceiling. Resale value adds a worthwhile bonus on top of the bill savings above, secondary to the running-cost case for installing solar.
How to get your own answer, not a rule of thumb
The free Easy Solar app turns the ranges above into a system size, cost, savings and payback estimate built specifically for your own house. Answer a few questions about your roof and how your household uses power, and it does the personalising for you: no quote form, no installer follow-up call, no commission on the other end.
That personalising matters because every figure on this page is a national average, and solar still sits at around 4% of New Zealand homes, a minority choice, though a fast-growing one: around 1,000 new home systems are going in every month.
Your roof's actual orientation and shading, your household's actual daytime usage, and your actual power plan and retailer all move the real answer meaningfully in either direction from the averages above.
The short version
If your roof gets good sun (north, northeast or northwest, without heavy shade), you use a fair share of your power during the day or can shift some to suit, and you're staying put for more than a few years, the numbers stack up: expect payback in 7 to 10 years and free power for a decade or more after that.
If your roof faces south or sits under trees, you're out all day with no plan to shift usage, or you're selling within 2 to 3 years, the honest answer is not yet.
Beyond the dollars, ask yourself:
- Do you want the lights to stay on in an outage?
- Do you want to be protected from the next power price shock?
- Do you want to lock in a power price for the next 25 years instead of riding grid prices up every year?
Get a personalised read on your own roof, usage and payback with the Easy Solar app. It's free, and there's no quote to sit through.
Common questions
Footnotes
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Rewiring Aotearoa, Electric Homes & Vehicles (June 2026), peer-reviewed by economist Cameron Bagrie and physicist Shaun Hendy. ↩ ↩2