Solar Panels in New Zealand: Is It Worth It?

Solar panels work in NZ. Yes, even in Wellington. The real question isn't whether you'll generate power—it's whether the maths makes sense for your home and wallet.

At a Glance

Typical cost: $7,000–$18,000 (6–10kW system, including installation)
Potential annual savings: $800–$2,000+ depending on system size and consumption
Government subsidies: None for residential solar (unlike heat pumps)
Best for: Homes with good roof orientation, decent sunlight, and daytime power use
Installation time: 1–3 days
Expected lifespan: 25–30 years (inverter may need replacing after 10–15 years)

Does solar actually work in NZ?

Yes. New Zealand gets more solar radiation per square metre than Germany, which happens to be the world's largest solar market by capacity. That should tell you something.

Your location matters, though. The top of the South Island and Bay of Plenty get the most reliable sun. Auckland and Wellington still get enough—north-facing roofs in Wellington generate solid power year-round. Even Dunedin and Southland aren't ruled out.

The catch is seasonal variation. You'll generate roughly 2–3 times more power in summer than winter. Your panels won't make much of a dent on dark July mornings, but they'll work hard in December and January. For most Kiwi homes, that's fine—it actually matches when you need less heating and more cooling.

How home solar works

Panels on your roof convert sunlight into direct current (DC) electricity. An inverter converts that to alternating current (AC)—the stuff your fridge and lights actually use. Whatever power you generate gets used first, and any excess gets exported back to the grid.

Your power company pays you a buy-back rate for exports, typically 7–12c/kWh depending on your retailer. You're still connected to the grid, so you pull power at night and during cloudy spells at the standard rate you're charged (usually 30–35c/kWh). This isn't about going off-grid—it's about making your own power and selling the leftovers.

The monitoring system lets you see generation in real time via an app. You can watch your panels work, which sounds silly but feels good.

System sizes for NZ homes

Small system: 3–4kW (8–10 panels)

Suits a couple or small household with modest daytime power use. Roughly generates 4,000–5,000 kWh per year depending on location. Good if you're renting or have space constraints. Less impressive payback unless power bills are high.

Medium system: 6–8kW (16–20 panels)

The sweet spot for most NZ families. Covers a typical family's daytime use and leaves enough for export. Generates 7,000–9,500 kWh annually. Takes up most of a north-facing roof. This is what most installers recommend.

Large system: 10kW+ (25+ panels)

Worth it if you're a big household, heating with a heat pump, charging an EV, or running a pool pump. Generates 12,000–15,000 kWh yearly. Needs a decent roof and careful wiring. Makes more sense when you can use the power yourself rather than export it. Pairing solar with a hot water heat pump can slash your power bill even further — see our hot water heat pump guide.

Most NZ residential installs land in the 6–10kW range. Bigger isn't always better—oversizing means more export at low rates, which kills your ROI.

What it costs

A 6kW system (typical family size) costs roughly $7,000–$12,000 installed, including inverter, labour, and grid connection. A 10kW system runs $10,000–$18,000. These prices include GST and are what you'd actually pay an installer today.

Prices have dropped significantly over the past five years—about 30–40% in real terms. A system that cost $20,000 in 2019 costs $12,000 now. That trend is likely to continue.

If you want to add battery storage, expect another $8,000–$15,000. Batteries are attractive if you want maximum self-consumption or blackout protection, but they're not essential for most grid-connected Kiwi homes yet. The payback on batteries is longer and less certain than the panels themselves.

Some installers offer equipment bundles or financing options built in. Always get 3 quotes and compare the same system size and brands—a cheap quote might mean different panels or a weaker inverter.

The payback question

A typical 6–8kW system pays for itself in 5–8 years. After that, you're essentially running on free electricity for the remaining 15–20 years of the panel's life. That's a solid return.

The payback depends on three things: your current power bill, how much power you use during the day, and your buy-back rate. If you work from home or have flexible loads (like charging an EV), payback is faster. If you use most power at night (like a standard household), you export more and payback is slower.

Here's the maths that matters: a kWh you export is worth 7–12c. A kWh you buy costs 30–35c. Self-consumption is worth roughly 3 times more than exporting. So the best ROI comes from using your own solar power during the day, not selling it back.

After payback, the economics are simple. You've got essentially free electricity for another 15+ years. Your panels will still work—they typically degrade only 0.5% per year—and your inverter might need replacing around year 15 for $2,000–$3,000. Even with that cost, you're ahead.

Do you need a battery?

Probably not yet, unless you've got specific reasons.

Batteries make sense if you have frequent power cuts, want to maximise self-consumption, or are installing an EV charger. They also make sense if you generate way more power than you use and export at low rates. But for a typical grid-connected Kiwi home, a battery adds cost that doesn't pay back quickly.

Battery prices are falling fast—what cost $15,000 last year costs $12,000 now. In another 3–5 years, the maths might tip in favour of batteries even for standard homes. You don't need to decide now. Most systems are designed to add batteries later.

For more on pairing solar with EV charging, see our EV charger installation guide.

Financing

No government rebate exists for residential solar in New Zealand, unlike heat pumps. But the major banks offer green loans specifically for solar systems.

ANZ, BNZ, and ASB all have green loan products with rates around 0–1% interest above their standard rates, terms of 3–5 years, and limits of $40,000–$80,000. To qualify, your system must be installed by a SEANZ (Solar Energy Association of New Zealand) member.

Loans beat paying cash if you're not in a rush and want to spread the cost. The interest you pay is usually far less than what you'll save in power bills, so the maths favours borrowing.

Some installers also offer payment plans or finance partnerships. Always ask what options are available and compare the total cost.

Choosing an installer

Find someone who's a SEANZ member—that's a basic quality bar. Check they're a licensed electrician and that they handle the grid connection paperwork with your power company (you shouldn't have to).

Ask about the panel and inverter brands. Tier 1 panel brands (like Canadian Solar, JinkoSolar, Trina) have reliable warranties and resale value. Inverters from SMA, Fronius, or Goodwe are solid choices. Dodgy brands are cheap upfront but hurt resale value and warranty support.

Get 3 quotes. Compare like-for-like: same system size, same panel brand, same inverter. Prices should be within 5–10% of each other. If one quote is wildly cheap, ask why.

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What to ask your installer

What system size do you recommend based on my power usage and roof space? They should explain the logic—typical consumption, roof orientation, shading, how much you can actually use.
What panel and inverter brands are you proposing, and why? A good installer explains their choice, not just naming the cheapest option.
What's the expected annual generation in kWh for my location and roof orientation? They should give you a specific figure, not a range. If they can't, ask why.
Do you handle the grid connection application with my power company? You want them to manage this paperwork and get signed off before installation.
What monitoring system is included so I can track generation? Most include a simple app. Check it works before you sign off on installation.

The honest takeaway

Solar makes financial sense for most NZ homes, especially if you've got good roof orientation and use power during the day. The payback is real, the technology is reliable, and prices keep falling.

It's not a subsidy or a free lunch. You're making an investment that returns cash over time. But once it's paid for, you're sitting on a power generator that'll keep working for another 20 years.

Not sure what your home needs? Take our free 2-minute Home Energy Assessment →

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