Key takeaways
- EECA recommends getting 2 or 3 quotes.
- Minimum warranties: panels 10 years, string inverters 5, microinverters 10, lithium batteries 10, workmanship 5.
- Deposits are typically 10% to 30% of the total (EECA).
- Compare price per watt: installed price ÷ system size in watts.
- Ask when the balance is due, and what protects you if the company stops trading.
What a quote must include
EECA's list: scaffolding or edge protection, all components (cabling, inverters, controllers, surge protection, racking), roof work, consent applications, inspections, distribution upgrades, the import/export meter, and a battery install if you're getting one.
- Scaffolding or edge protection, if required
- Components: cabling, inverters, controllers, surge protection and racking
- Any necessary roof work
- Any necessary consent applications
- All inspections required
- Any potential distribution upgrade
- The import/export meter
- Battery storage installation, if applicable
Minimum warranties
EECA's minimums: 10 years on panels, 5 years on string inverters, 10 years on microinverters, 10 years on lithium-ion batteries and 5 years on workmanship. Anything shorter is a reason to ask why.
| Item | Minimum warranty |
|---|---|
| Panels (product) | 10 years |
| String inverter | 5 years |
| Microinverters | 10 years |
| Lithium-ion battery | 10 years |
| Workmanship | 5 years |
The price-per-watt test
Divide the installed price by the system size in watts. On Solar Scout's 2026 ranges, 6.6kW works out at about $2.12 to $2.27 a watt and 10kW at $1.50 to $1.80. A much higher figure should come with a reason, such as a two-storey roof, premium panels or a battery.
Deposits and when you pay the balance
EECA says deposits are typically 10% to 30% of the total cost. The bigger question is when the balance is due. Paying most of it before the system is commissioned and certified leaves you exposed if something goes wrong.
With us: $250 to book the survey (refundable until you sign), a contract deposit after you accept the fixed price, and the balance only after commissioning and certification. See how it works.
Questions to ask every installer
Who does the electrical work and are they registered? Which lines company application is included? Which exact panel and inverter models? What does the monitoring show? Who honours the workmanship warranty if the company stops trading?
- Is the installer SOLASSURE certified or a member of an industry body?
- Are the electricians registered with the EWRB?
- What's the export limit your lines company allows, and is that application included?
- Is the price fixed, and what would change it?
- When is each payment due?
Frequently asked questions
How many solar quotes should I get?
EECA recommends 2 or 3 (EECA).
What deposit is normal for solar in NZ?
10% to 30% of the total, according to EECA.
What warranty should solar panels have?
At least 10 years on the panel product, and 5 years on workmanship (EECA minimums).
What is SOLASSURE?
An NZ quality mark for solar installers. See solassure.nz.
Why do quotes for the same size differ so much?
Roof type and height, panel and inverter brands, whether scaffolding and the meter are included, and margin. The checklist above makes differences visible.
Sources
- EECA, Solar quotes and installation (checked Sept 2026)
- Solar Scout, Solar panel costs NZ (checked Sept 2026)
- SOLASSURE quality mark (checked Sept 2026)
General information, not financial advice. Prices and rates change; each figure shows where it came from and when it was checked.