What to Ask a Solar Installer Before You Sign a Quote
Before signing a solar quote, ask the installer to explain the assumptions behind it. Brand names and system size matter, but they do not tell you whether the quote fits your roof, bill, switchboard, export conditions or future plans.
A good installer should be able to answer practical questions without making you feel difficult for asking.
- Ask what the savings estimate assumes about usage, export and tariffs.
- Confirm what electrical, roof, metering and compliance work is included.
- Treat vague answers, rushed pressure and unclear exclusions as reasons to pause.
The mistake to avoid
The mistake is signing because the quote has a familiar system size, a confident savings number or a limited-time discount. Those details may be relevant, but they are not enough.
A solar quote is really a set of assumptions. It assumes a roof layout, an inverter choice, an export outcome, a usage pattern, a tariff and a scope of work. If those assumptions are not visible, the household is taking on risk it may not understand.
Questions about the system design
Start with the design. You want to know why this system has been proposed for this home.
- Why this system size?
- Which roof faces will be used?
- How has shade been assessed?
- What production estimate is being used?
- What happens if part of the roof is shaded at different times of year?
- What monitoring will I be able to see after installation?
Questions about the money
Savings estimates deserve careful reading. Ask the installer to separate what comes from self-used solar and what comes from exported solar.
| Quote item | Why it matters | Question to ask |
|---|---|---|
| Usage assumption | Drives the savings estimate | What daytime usage pattern have you assumed? |
| Feed-in tariff | Affects export value | What export rate have you used, and can it change? |
| Retailer plan | Shapes import and export value | Does this quote depend on changing plans? |
| Payback estimate | Can hide optimistic assumptions | What would the result look like under a lower export rate? |
| Future loads | May justify a different size | Have EV charging, batteries or electrification been considered? |
Questions about installation scope
The cheapest quote is not always the cheapest finished job. Ask what is included before comparing prices.
- Is switchboard work included or excluded?
- Is metering work required?
- Who performs the fixed electrical work?
- What roof access or roof repair issues could change the cost?
- What warranties apply to panels, inverter, workmanship and installation?
- What paperwork will I receive after installation?
These questions are not nitpicking. They protect the household from discovering missing costs after the deposit has been paid.
Red flags
Be cautious if the salesperson cannot explain the quote, discourages written questions, gives only broad savings claims, or pushes for a same-day decision before the site and bill have been properly considered.
A strong quote should survive calm scrutiny. If the advice changes every time you ask for detail, wait.
Before signing a solar quote, make the assumptions visible. The right installer should be willing to explain system size, production, export, installation scope and warranty details in plain English.