Best Solar Design Software New Zealand: 2026 Guide

New Zealand quietly became one of the more interesting solar design markets on 1 July 2026. Since that date the four largest retailers, holding roughly 87 percent of connections between them, have been required to offer a plan where the export rate varies through the day. The rule sets the shape of the price, not its level, so retailers place the peaks where they choose and there is no floor. The peaks generally fall in the evening, after solar generation has collapsed. That single fact turns a generation problem into an arbitrage problem, and it means a design tool that cannot dispatch a battery against an hourly price profile cannot size a New Zealand system properly. This guide covers what the market now requires, and which tools deliver it.

Short version. The best solar design software for New Zealand installers in 2026 is SurgePV, because time-varying export made battery dispatch against an hourly price profile the central design task and SurgePV simulates it directly. PVsyst is the bankable reference for large commercial and ground-mount. PV*SOL is credible for residential detail. Aurora assumes US net metering, which New Zealand does not operate.

For the quoting side see our best solar proposal software New Zealand guide, and the global best solar design software ranking for the category without the local lens.

The Peaks Fall When The Array Is Asleep

This is the central New Zealand design fact and it is worth stating without hedging. On time-varying export plans, the highest rates are generally paid in the evening. Solar arrays generate nothing in the evening.

The design response is storage, and the reasoning is unusually clean. A battery charged from midday surplus and discharged into the evening peak is not merely shifting consumption, it is buying energy at the trough rate and selling it at the peak rate, with the array supplying the energy for free. On a plan with a wide spread that is a genuinely attractive arbitrage.

It also means two households on the same street with identical arrays can have quite different optimal configurations depending on which plan they are on. That is unusual, and it makes the retailer question part of the design process rather than an afterthought.

The Retailer Spread Is The Largest Variable In The Model

New Zealand has no government-mandated feed-in tariff. Every rate is a commercial term set by the retailer and changeable.

Published rates span a wide range. Among the majors the low end sits around 5 cents per kWh, flat plans such as Meridian Solar Plan and Octopus Flexi reach 17 cents, and peak rates go considerably higher, including around 24 cents on Meridian’s winter peak and up to 40 cents on Octopus OctopusPeaker in winter.

Two design consequences follow.

The plan is a design input, not a footnote. A spread this wide changes the optimal array size, the storage case, and whether the project makes sense at all. Any tool that treats the export rate as a single configurable number, rather than an hourly profile per retailer, is losing most of the available accuracy.

Self-Consumption Still Beats Arbitrage, Usually

It is worth keeping the hierarchy straight, because the excitement around time-varying rates can obscure it.

A kilowatt-hour the household consumes directly avoids the retail import price, which is generally higher than any export rate on offer. A kilowatt-hour stored and exported into the evening peak earns the peak export rate. On most plans the first is still worth more than the second.

So the design ordering is: maximise direct self-consumption first, then use storage to cover the household’s own evening demand, and only then consider exporting stored energy into the peak. A battery that discharges into the house during the evening is doing the highest-value thing available. Exporting into the peak is what it should do with whatever is left.

The exception is plans with unusually high peak export rates, where peak export can approach or exceed the import price. There the ordering can genuinely flip for part of the evening, and only an hourly model comparing both against the actual load will find the crossover. This is the kind of optimisation that is trivial to state and impossible to do by hand.

The Rest Of The New Zealand Requirement Set

AS/NZS 4777.2 governs grid-connected inverter requirements and AS/NZS 5033 the array installation, both shared with Australia. The trans-Tasman basis means much of the Australian component library and compliance work carries across, which is convenient for installers operating in both markets.

Winter peaks matter more than in most markets. Several of the highest export rates are winter-specific, and New Zealand winter generation is materially lower than summer. A design optimised on annual averages will misjudge the value of a winter peak plan, because the hours when the rate is highest are also the hours when there is least energy to sell.

Regional variation. New Zealand spans a considerable latitude range and its climate varies sharply between regions and between the islands. Site weather data rather than a national assumption.

The Six Platforms New Zealand Installers Should Evaluate

1. SurgePV, the all-in-one pick

Hourly export price profiles configurable per retailer plan, battery dispatch optimisation against both load and export price, 8,760-hour simulation, AS/NZS standards library shared with Australian work, AI 3D roof modelling from satellite imagery, and white-label proposals with e-signature generated from the same design record. $1,299 to $1,899 per user per year.

2. PVsyst

The bankable reference for large commercial and ground-mount projects, frequently named by lenders. Strong simulation, no proposal layer, retailer plan logic applied manually. See our PVsyst alternative review.

3. PV*SOL

Capable residential and small commercial modelling with good component libraries and solid self-consumption tooling. Desktop-based. Our PV*SOL alternative guide covers the trade-offs.

4. OpenSolar

Free, quick, and widely used in trans-Tasman residential work. Weaker on the hourly dispatch against time-varying export prices that now decides the New Zealand answer. See our OpenSolar alternative comparison.

5. Aurora Solar

Strong residential design built around US net metering, which New Zealand does not operate. See our Aurora Solar alternative comparison.

6. Spreadsheets plus a yield tool

Still common in smaller practices, and the most likely place a single flat buyback rate is standing in for an hourly profile.

New Zealand Solar Design Software Comparison

Worked Example: 6 kW Array, Flat Plan Versus Time-Varying With Storage

An illustrative calculation showing where the value moves, not a specific customer project. Inputs: 6 kW array, household with modest daytime and strong evening consumption, three configurations compared.

Column B is the trap the July 2026 change created. A household moved onto a time-varying plan without storage is worse off than on a decent flat plan, because all its export lands in the trough and it buys its evening energy at retail. The headline peak rate on that plan is real and entirely out of reach.

Column C is what the plan is designed to reward. The battery serves the evening load first, avoiding retail import, and exports what remains into the peak. Whether the hardware cost justifies it depends on the size of the spread and the household’s evening demand, which is a calculation rather than a rule.

The practical advice for installers is that recommending a time-varying plan and recommending storage are the same recommendation. Splitting them leaves customers in column B.

Who Should Choose What

• Choose SurgePV if you need hourly export profiles, battery dispatch and retailer plan comparison in one tool.
• Choose PVsyst where a lender names it on commercial or ground-mount work, paired with separate quoting.
• Choose PV*SOL if your team is desktop-based and does detailed residential modelling.
• Avoid flat-rate export assumptions. Since July 2026 they misrepresent the majority of the market.

The Bottom Line

New Zealand solar design changed character in July 2026 and most quoting has not followed.

• Treat the retailer plan as a design input. Rates span 5 cents to 40 cents depending on plan and hour, and that decides the optimal configuration.
• Recommend the plan and the battery together. A time-varying plan without storage leaves the customer exporting into the trough and importing at the peak.
• Keep self-consumption first. Direct use still beats peak export on most plans, and it is insulated from rate changes.