15 Questions You MUST Ask Before Signing a Solar Contract (Installer Checklist)
- 3 hours ago
- 6 min read
Switching to solar is a major long-term investment. However, signing the wrong contract can cost thousands in hidden fees, poor performance, or service headaches.
That’s exactly why knowing the questions to ask solar installers before signing is critical. This guide provides a complete solar checklist Australian homeowners can rely on, so you can confidently review any quote or proposal.
Whether you're a homeowner, commercial property manager, builder, developer, or non-profit organisation, this installer checklist will protect your investment.
Key Takeaways
The right questions to ask solar installers can prevent costly contract mistakes
A proper solar checklist ensures you compare quotes fairly
Understanding solar contract questions protects warranties and rebates
A transparent installer will confidently answer all 15 questions
Table of Contents
Here’s what you’ll learn in this solar quotes comparison guide:
Why Asking Solar Contract Questions Matters
Not all solar quotes are equal. In fact, two systems may look similar on paper but perform very differently over time.
Many Australians rush into signing because the price seems attractive. However, without a proper solar checklist, you may overlook critical details like panel, inverter and battery quality, system design, electrical workmanship, and experience of the installation team.
According to the Solar Accreditation Australia (SAA), using accredited installers reduces long-term risk and ensures compliance with Australian standards. You can verify accreditation through the official website.
Before signing any agreement, go through these 15 essential solar contract questions.
System Design & Performance Questions
1. What system size is recommended for my usage?
Ask how they calculated system size. Did they review your electricity bills? Did they factor in future usage like EV charging?
A proper installer designs for your actual consumption, not just roof space. The best way to work out what size system is optimal for you is to look at the Average Daily Usage in kW on your electricity bill, and divide that by the average peak sunlight hours in Melbourne (which is three), which will give you the right size system for you.
Many installers just sell standard-sized packages rather than customising the system size to your current usage and future plans.
2. How much will this system realistically produce annually?
Request estimated kWh output. Additionally, ask how shading, roof angle, and Melbourne weather affect production.
Ask if the system has been designed with future plans in mind (such as adding EV chargers, batteries, and moving to all-electric away from gas).
This is one of the most important questions to ask solar installers, because savings depend on output.
3. What assumptions were used in the savings estimate?
What electricity rate was used? A good system design will use the rate on your current electricity bill.
What feed-in tariff assumption? Feed-in tariffs are very low now compared to what they used to be and only have a minimal impact on the Return on investment of your solar system. Some quotes exaggerate feed-in tariff income.
Is battery storage included in projections?
4. Is my roof orientation and shading suitable?
North-facing roofs perform best in Australia. However, east-west systems still perform very well, capturing both morning and afternoon sunlight. A South roof should only be used with tilts so the panels are placed on the south face north, or if there is very limited usable roof space.
A site inspection should happen before the installation date to check everything. A good installer will do a site inspection even after a refundable deposit has been paid, just to check there are no surprises on the day. Some installers have vague terms and conditions about addons, don’t check your site and then add a heap of costs on the day in “add-ons” to what was originally a cheap quote. A good installer will tell you about any required add-ons before the installation date. These could include switchboard upgrades, additional labour for panel orientation, or installing hand railing on the roof for two-storey buildings.
Product & Warranty Questions
5. What solar panel brand and model are included?
Not all panels are equal. Ask about:
Check if they have Tier-1 manufacturer status. Tier 1 manufacturers are large, vertically integrated companies that have manufactured their own solar panels for over five years and are considered "bankable". A Tier 1 rating does not guarantee the highest quality or best performance; it primarily means financial institutions trust the brand to honour warranties.
What is the performance degradation rate? This will help you understand how long into the future you can expect your panels to be performing.
Product warranty (usually 15–25 years)
How the particular brand of panels manages shading (Is it a split panel so that if one area of the panel is shaded, the rest of the panel keeps performing?).
6. What inverter brand is included?
The inverter is the system’s brain. This is one of the most critical components of a solar system, so the quality of the inverter really matters. Therefore, ask:
String inverter or microinverters?
Warranty length?
Local service support in Australia?
Ask what specific features and functions the brand of inverter has to match your needs.
Look up reviews on specific inverter brands to see what customers and installers say.
7. What is the workmanship warranty?
Many buyers overlook this critical question in solar contracts.
Ask:
Is workmanship covered for 5, 10, or 15 years?
Who handles warranty claims?
Beware of phoenix companies that offer unrealistic long warranties. Solar Victoria recommends a 5-year workmanship warranty. When a company offers longer than that, it can be a red flag that they don’t plan to be around for a long time, so they can promise anything in terms of warranty but may not be around to service the warranties. Look up a company's Australian Business Number (ABN) and see how long they’ve been in business. If they’ve not been in business long, that’s a red flag. You want to go with companies that have been around longer than their warranty period.
Installation & Accreditation Questions
8. Are you SAA accredited?
Always verify Solar Accreditation Australia. This ensures compliance and eligibility for STCs (Small-scale Technology Certificates).
You can check installer credentials via the Solar Accreditation Australia (SAA) website.
9. Who will actually install my system?
Some companies subcontract installations. Therefore, ask:
Are installers employees or contractors?
How experienced is the team?
Companies that have their own in-house team of electricians who are accredited solar installers can ensure a high quality of workmanship, after-sales service and support. When companies outsource the installation, it can be frustrating as customer to try to get after-sales service and support as the solar retailer will pass responsibility to the installer ( a different company).
10. Will I need a switchboard upgrade?
Older homes may require electrical upgrades. This cost should appear clearly in your quote.
If it’s missing, ask directly.
Pricing & Contract Transparency Questions
11. Is this a fixed price contract?
Avoid vague contracts. Instead, confirm:
Are there additional call-out fees?
Is scaffolding included?
Are meter upgrade costs included?
12. What payment schedule applies?
A typical structure may include:
Deposit
Balance after installation
Final payment after grid approval
Never pay 100% upfront.
13. What happens if installation is delayed?
Weather, approvals, or supply delays happen. Therefore, clarify timeline expectations.
In Melbourne, installation typically takes 1–2 days. Grid approval may take 1–4 weeks.
Rebates & Compliance Questions
14. Am I eligible for rebates under Solar Victoria?
Victoria offers rebates and interest-free loans (subject to eligibility). Always confirm:
Is the installer approved under Solar Victoria?
Are rebates included in the quoted price?
Check official rebate updates at the Solar Victoria website.
15. Who handles grid connection and paperwork?
A professional installer manages:
STC processing
Grid connection application
Compliance certificates
If you’re handling paperwork yourself, that’s a red flag.
Bonus: Quick Solar Installer Checklist Australia Summary
Before signing, confirm:
✔ SAA accreditation
✔ Transparent pricing
✔ Clear warranty terms
✔ Realistic production estimates
✔ Rebate eligibility
✔ Grid approval process explained
Using this solar checklist Australia homeowners trust ensures you compare quotes fairly.
Why Choose Energy Wired?
At Energy Wired, we bring over a decade of industry experience delivering high-performance solar systems across Melbourne and Victoria.
What Sets Us Apart
SAA-accredited installers
Premium panel and inverter brands
Transparent contracts with no hidden fees
Detailed system performance modelling
Ongoing after-sales support
Most importantly, we encourage customers to ask every one of these questions to ask solar installer before signing.
Conclusion
Signing a solar contract is a major investment. However, asking the right solar contract questions protects your savings and your peace of mind.
By using this 15-point solar checklist Australia, you can confidently compare quotes and avoid common installer mistakes.
If you're considering solar in Melbourne, speak with Energy Wired today for a transparent, obligation-free quote.
About the Author:
Clifford Wigg is an Accredited Solar Designer and Installer with 15 years of experience in the solar industry and 24 years of experience in the electrical field. He is accredited in the design and installation of grid-connected photovoltaic (PV) systems, battery storage systems, and standalone (off-grid) power systems.
As the owner of Energy Wired, Cliff leads a team of highly trained electricians delivering high-quality workmanship across Victoria. Energy Wired specialises in customised system design, premium products, and long-term value for every customer.
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