Solar
Is solar worth it in New Zealand?
The return comes from electricity you do not buy, so it turns on your retail rate and on how much of the production your household actually uses. Both are things you can check before getting a quote.
Solar pays back on electricity you stop buying. That framing does more work than any other single idea in the subject, and it points straight at the four things that decide the answer.
1 · What you pay per unit
The higher your retail rate, the more each generated unit is worth. The national average as at May 2026 was 42.04c per kWh including GST, but the spread across the 42 towns MBIE surveys is wide: 37.01c in Wellington City against 52.52c in Balclutha.
That is roughly a 40% difference in what every displaced unit is worth, before anything about the roof is considered. Most of it is lines charges, which is why it tracks the network rather than the weather. Check your own town's figure. It is the first number in this calculation, not the last.
2 · How much of it you actually use
Production only displaces your retail rate if the house consumes it as it is made. Anything left over is exported at the buy-back rate, which is set by your retailer and is normally well below what you pay to import.
So a household that is home during the day, or that can move load into daylight hours, gets substantially more from the same array than one that is out from eight until six and exports the midday peak.
Things that genuinely shift consumption into production hours:
- Hot water on a timer. The single largest and most movable load in most New Zealand homes.
- Dishwasher and washing machine on delay start.
- An EV charged during the day at weekends or when working from home.
- A heat pump run to pre-warm the house in the afternoon rather than at six.
- A battery, which converts the problem into a storage problem, at a cost.
3 · What the system costs
Which we do not publish, and which is the input you get from quotes. The cost page covers what drives it and how to compare two quotes on the same basis.
4 · How long you will be there
Solar is an asset attached to a house. If you sell in three years, the return is whatever it added to the sale price plus three years of savings, and the first of those is genuinely uncertain. Over fifteen years it is a straightforward calculation. Over three it is a bet on the property market.
Working it out
- Get your annual kWh off a power bill.
- Get your town's price per kWh, which we publish for every town MBIE surveys.
- Ask the installer for modelled annual production and the assumptions behind it.
- Estimate what share of that production you would use rather than export, honestly, based on who is home and what you can shift.
- Value the used share at your retail rate and the exported share at the buy-back rate your retailer actually offers. Ask them, in writing.
- Compare the annual figure to the quote.
That is a spreadsheet afternoon and it beats any rule of thumb, because the rules of thumb are all built on someone else's step 4.
Where the honest uncertainty is
Steps 3 and 5. A production model is an estimate with assumptions in it, and a buy-back rate is a commercial term that can change. Both are worth getting in writing, and both are worth being sceptical of when they arrive rounded and optimistic.
Is solar worth it? — common questions
How long does solar take to pay back in New Zealand?
There is no single figure, because the two biggest inputs vary by household. Those are what you pay per kilowatt hour, and what share of the production you use rather than export. A household in an expensive network area that is home during the day sits at one end; one in a cheap area that is out all day and exports most of the production sits at the other. Work out both before accepting any payback estimate.
What is the single biggest factor in whether solar is worth it?
Self-consumption, meaning the share of what you generate that your household uses at the moment it is generated. Electricity used at home displaces your retail rate, currently 42.04c per kWh nationally. Electricity exported earns the buy-back rate, which is normally much lower. Two identical systems can have very different returns on that basis alone.
Does it matter where in New Zealand I live?
More than most people expect, and mostly through price rather than sunshine. Across the 42 towns MBIE surveys, the range runs from 37.01c per kWh in Wellington City to 52.52c in Balclutha. The same array displacing the same units is worth substantially more at the top of that range.
Is solar worth it if nobody is home during the day?
It can be, but the case is weaker and it depends on what you can shift. Hot water on a timer, a dishwasher and washing machine on delay start, and an EV charged at midday on weekends all move consumption into production hours without anyone being there. Without any of that, most of the output is exported at the buy-back rate and the return drops accordingly.
Should I get a battery to make solar worth it?
Treat it as a separate decision with its own arithmetic. A battery raises self-consumption, which is the right lever, but it adds a substantial cost and its own lifespan. It is worth pricing solar with and without one and comparing the two returns rather than assuming the pair go together.
What we don't publish about solar
- We do not list, rank or recommend solar installers. There is no installer inventory behind this site — no verified data on any of them, and no commercial arrangement with any of them.
- We do not publish buy-back or export rates. They are set per retailer, they change, and we hold no verified rate file for any of them. Ask the retailer for their current rate in writing.
- We do not publish system prices. A quote depends on the roof, the switchboard and the install, and a number here would be a guess presented as a benchmark.
The part we can help with
Solar changes which power plan suits you, and that is an electricity decision rather than an installation one. We compare 8 power companies and can show you what each offers at your address — our comparison asks whether you have panels from the start.
Compare power companiesKeep reading
Related
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What solar costs
We publish no system prices, because a quote depends on your roof, your switchboard and your site. What we can do is show you what moves the number and how to compare two quotes on the same basis.
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Solar buy-back rates
Exporting surplus electricity earns a rate your retailer sets, and it is normally well below what you pay to import. That gap is why self-consumption matters more than array size.
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Switching with solar
With panels on the roof, you buy less electricity and you sell some. Both change which plan is a good deal, and the daily charge starts mattering more than the unit rate.
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Home batteries
A battery does one economic thing, converting exported units into used ones, and one practical thing, which is backup during an outage. They are separate decisions with separate arithmetic.