Solar install cost calculator
See what a solar power system actually costs installed in NZ, from a small starter setup to a full family-sized system.
What this means for you
See how the cost per watt drops as system size increases, since fixed costs get spread across more panels.
Compare system sizes
See how total cost scales (or doesn't) as system size increases — fixed costs stay similar regardless of size.
| Scenario | Size | Installed cost | $/watt |
|---|---|---|---|
| Small | 3kW | $0 | $0.00 |
| Current | 6.6kW | $0 | $0.00 |
| Large | 10kW | $0 | $0.00 |
This calculator uses a single blended $/watt rate, so cost scales in a straight line with size here — real-world quotes are less linear, since fixed costs like the inverter and labour don't grow proportionally with panel count, which is why the article below explains actual pricing tends to flatten out at larger sizes.
Assumptions & sources
Typical NZ solar installer quotes across system sizes, informed by SEANZ (Sustainable Energy Association NZ) member pricing trends.
1 July 2026
17 July 2026
Installed cost = system size (W) × cost per watt, plus battery capacity (kWh) × battery cost per kWh if selected.
Panels, inverter, racking, labour and standard installation, plus optional battery storage.
Switchboard upgrades, scaffolding for difficult roofs, and any council consent fees some installations require.
Related reading
Is solar really worth it?
Solar panels cost thousands upfront — here's when the payback maths actually works in your favour, and when it doesn't.
Read article →
How does NZ stack up against Australia in residential solar?
Australia has one of the highest rooftop solar rates in the world. Here's why NZ lags behind — and whether that's changing.
Read article →Why panels are only a third of the bill
Solar panel prices are misleading because the panels themselves are only around a third of what you pay — the rest is inverter, racking, switchboard work, labour, scaffolding and compliance paperwork. That's why a 3kW and 6.6kW system don't cost proportionally different amounts: the fixed costs are roughly the same regardless of size, which is exactly why 6.6kW has become the sweet spot for most NZ homes.
Above 6.6-8kW, the extra panels increasingly generate power you'll export rather than use yourself, which sells at the much lower buy-back rate rather than offsetting your retail bill — so bigger isn't always proportionally better once you're past your household's realistic daytime usage.
Frequently asked questions
A typical 6.6kW system, the most popular size, costs roughly $13,000-$15,000 fully installed in 2026 (about $1.70-$2.00/W). Systems range from around $8,000 for a small 3kW setup to $30,000+ for a large system with battery.
No national rebate scheme as of 2026, unlike Australia. Some banks offer green home loans at 0-1% interest through accredited installers, and a few councils or Kainga Ora programmes offer limited grants or interest-free loans.
