What Size Solar System Are Kiwis Actually Installing? (2026 Data)
By Kristy Hoare on in Solar Power Trends
Over the last 12 months, Kiwis have installed 13,455 new residential solar systems, with an average size of 8.3kW.
That’s roughly 18 to 20 panels per roof - quite a jump from the 3kW and 4kW systems that were common a decade ago. And system sizes are still growing. In August 2026 alone, the average new residential system was 9.08kW.
These figures come from the Electricity Authority’s EMI data, which tracks registered grid-connected solar systems across New Zealand, month by month. So we’re looking at actual installations here, rather than survey results or estimates.
The monthly number moves around a little, but the direction over the year is hard to miss. The first half of the period sat around 8kW. Since May it has not dropped below 8.7kW.
So why do you see 5.79kW quoted as the average?
Because there are two different questions hiding in the word average, and they give very different answers.
The 8.3kW figure is what people are installing now. The other number you will see is the average across every system currently sitting on a New Zealand roof, including the small ones fitted ten years ago that are still happily generating. That average is lower, and it moves slowly, because it is dragged down by a decade of older installs.
Here is where that installed base sits as at August 2026:
| System type | Average size |
|---|---|
| All residential solar | 5.79kW |
| Solar without a battery | 5.18kW |
| Solar with a battery | 7.68kW |
These figures describe recorded generation capacity in kW, not battery storage capacity in kWh. EMI does not record the size of the battery people install, only the solar capacity installed alongside it.
Both numbers are true and both are useful. If you want to know how much solar is on New Zealand roofs, 5.79kW is your number. If you are trying to work out what to put on your own roof, look at what is being installed today.
The gap between the two is getting wider
This is the part worth paying attention to. New installs have always been bigger than the national average, but the distance between them is growing quickly.
In August 2018, a new system averaged 4.62kW against a national average of 3.51kW. A gap of about 1.1kW.
In August 2026, a new system averaged 9.08kW against a national average of 5.79kW. The gap is now 3.3kW, three times what it was.
Put another way: the size of a new residential system has almost doubled in eight years, up 97%. The national average over the same period grew 65%. The market is moving faster than the fleet average makes it look.
Why systems keep getting bigger
Panels keep getting cheaper. Solar modules are one of the few products that reliably get cheaper per watt every year. Manufacturing scale, better cell efficiency, bigger panel formats. The panels themselves are now a surprisingly small slice of what you pay for a system.
Labour is not getting cheaper. Installer wages, scaffolding, compliance, travel, the electrician's time to connect it all. Those costs are flat to slowly rising, and they barely change whether you are installing 12 panels or 18. Same truck, same crew, same day on the roof, same inverter commissioning.
So the fixed cost of simply showing up is spread across more panels, and the cost per kW drops as the system gets bigger. A 4kW system costs more per kW than an 8kW system, every time. That is the single biggest reason sizes keep climbing.
Which means payback improves as you go bigger. Our analysis of actual payback periods for NZ homeowners backs this up. Bigger systems do not just generate more, they generate more per dollar spent. If you are going to the trouble of putting solar on the roof at all, undersizing it is usually the more expensive mistake.
More households have more to power. EVs are the clearest example. An EV is a second household's worth of electricity demand parked in the garage, adding roughly 2,000 to 3,000kWh a year. Solar and EVs go hand in hand, and people planning for one tend to size for both. The same goes for households moving off gas to electric hot water or induction cooking.
Battery homes install noticeably more solar
This is where the new-install figures really earn their keep. Over the last twelve months, new residential systems that included a battery averaged 9.26kW. New systems without a battery averaged 7.35kW.
Batteries are also no longer the minority choice. Of the 13,455 new residential systems installed over that period, 7,216 of them - 54% - went in with a battery.
The gap was at its widest in August 2026: 10.26kW for new battery systems, against 7.52kW for those without.
So why the difference? Without a battery, every kilowatt-hour your panels make that you are not using right at that moment gets exported to the grid. You get paid for it, but nowhere near what you pay to buy power back. Buy-back rates sit well below retail, so exported solar is worth maybe a third to a half of self-consumed solar.
That puts a natural ceiling on system size. Once you have covered your daytime load, every extra panel is earning the low rate rather than the high one, and adding more stops paying off.
A battery removes that ceiling. The midday surplus now has somewhere useful to go. It gets stored and used at 6pm when the oven and the heat pump are running, which means it is worth full retail instead of buy-back. Suddenly a bigger array makes sense, because you can actually consume what it makes.
One nuance worth noting. Across the whole installed base, battery homes have 48% more solar than non-battery homes (7.68kW against 5.18kW). On new installs that gap is 26% (9.26kW against 7.35kW). Battery systems are still the biggest by a clear margin, but systems without a battery have been growing quickly too.
System sizes by region
Averages vary around the country. The first column is every residential system currently on the register in that region. The second is the average size of systems newly installed there over the last twelve months, weighted by how many went in each month.
| Region | Homes with solar | All systems | New installs, last 12 months |
|---|---|---|---|
| Northland | 5,783 | 5.53kW | 8.06kW |
| Auckland | 15,489 | 5.37kW | 8.40kW |
| Waikato | 8,967 | 6.11kW | 9.81kW |
| Bay of Plenty | 7,296 | 6.00kW | 8.86kW |
| Gisborne | 603 | 4.67kW | 5.50kW |
| Hawke's Bay | 4,412 | 5.81kW | 9.16kW |
| Taranaki | 2,514 | 6.53kW | 8.49kW |
| Manawatu-Whanganui | 3,989 | 6.02kW | 8.90kW |
| Wellington | 7,696 | 5.70kW | 8.43kW |
| Tasman | 2,202 | 6.52kW | 8.89kW |
| Nelson | 1,713 | 5.58kW | 7.59kW |
| Marlborough | 1,614 | 5.43kW | 6.00kW |
| West Coast | 323 | 6.77kW | 8.17kW |
| Canterbury | 14,584 | 5.82kW | 7.13kW |
| Otago | 5,605 | 5.94kW | 8.99kW |
| Southland | 925 | 5.73kW | 7.45kW |
Every region without exception is installing bigger systems today than its own historical average, and in most cases by 2kW to 3kW. But the two columns rank the regions quite differently, which is the interesting part.
Ignore Gisborne. There were only 40 new systems in the entire region over twelve months, and several of those months record a flat 5.000kW, which looks like a default value rather than a measurement. Both Gisborne columns are noise. The West Coast, at 111 new installs, is thin for the same reason, though less so.
Waikato installs the biggest systems in the country. At 9.81kW over the last year it is comfortably ahead of everywhere else, and consistently so: every single month in the period landed between 8kW and 11kW. This is not one big install skewing things.
Canterbury is the busiest market but not the biggest systems. 2,726 new installs in twelve months, more than any other region by a clear margin, yet an average of 7.13kW, well below the national 8.3kW.
Auckland looks very different depending on which column you read. Its installed base is the second smallest in the country at 5.37kW, which fits the usual explanation: denser housing, more townhouses and terraces, smaller and more broken-up roofs, more shading. But its new installs average 8.40kW, slightly above the national figure. Whatever roof constraints Auckland has, they are not holding back what is going on today nearly as much as the fleet average suggests.
Provincial and rural regions cluster at the top. Hawke's Bay 9.16kW, Otago 8.99kW, Manawatu-Whanganui 8.90kW, Tasman 8.89kW, Bay of Plenty 8.86kW. More standalone homes on bigger sections with simpler, larger roof planes, and a lot of lifestyle blocks with bigger loads attached. Sheds, workshops, bore pumps, water pumps, sometimes more than one EV in the driveway. More roof and more to power pushes system sizes up.
What size should you choose?
The national average is useful context, but your home does not need an average system.
Look at your electricity use, when you use it, your usable roof space and what might change over the next few years. A battery, EV or move from gas to electric hot water can all change the calculation.
My advice? Do not automatically choose the smallest system because it has the lowest upfront price. And do not automatically ask for the system you would have bought five years ago either. Panels are the cheap part now. Getting the crew on your roof is the expensive part, and you only want to pay for that once.
Ask your installer to show you what the next size up costs, how much extra electricity you are likely to use, and what that does to the projected payback.
Sometimes a few more panels make a lot of sense.
And if you are considering a battery, or think you might add one later, size the array with that in mind. A battery with too few panels to fill it is an expensive way to store not very much.
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Data source: Electricity Authority, EMI installed distributed generation trends, residential connections. All figures to 31 August 2026. Twelve-month new-installation averages cover September 2025 to August 2026 and are weighted by monthly install volume.