How to Compare Solar Quotes in Australia

12 Things to Check Before You Sign

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You have three solar quotes. Each company recommends a similar-sized system, uses familiar equipment, and promises significant electricity savings. One quote is thousands of dollars cheaper, so choosing should be easy.

Unfortunately, the number at the bottom of a solar quote rarely shows if you are comparing the same thing. One quote may include a switchboard upgrade, blackout backup, site-specific system design, and comprehensive warranties. Another may use the same system size but exclude essential electrical work, offer less usable battery storage, or rely on assumptions that don’t match your household's electricity use.

The differences become clear only after you have signed, paid a deposit, or committed to finance. Learning to compare solar quotes properly helps you avoid an undersized system, unexpected installation costs, and equipment that doesn’t perform as expected. Here are 12 things every Australian homeowner should check before accepting a solar or solar-and-battery quote.

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Why Comparing Solar Quotes on Price Alone Can Cost You More

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Solar is not an off-the-shelf product. Panels and batteries arrive in boxes, but the system must be designed and installed for your property. The final result depends on:

• Your electricity consumption
• When your household uses power
• Roof layout and orientation
• Shading
• Switchboard condition
• Single-phase or three-phase supply
• Network export limits
• Existing solar equipment
• Battery and inverter compatibility
• Installation quality
• Monitoring and commissioning
• Warranty and after-sales support

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Two quotes showing “10kW solar” do not necessarily describe equivalent systems. They may use different numbers of panels, inverter capacities, panel layouts, installation methods, and performance assumptions. The same applies to battery storage. A quote for a “15kWh battery” may refer to total capacity rather than the amount available for your home. Blackout backup may be included, offered as an extra, or not supported by the configuration. Price matters, but compare it after you understand what each company provides.

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1. Is the System Designed Around Your Electricity Usage?

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The first question isn't which panel or inverter brand appears on the quote, but whether the recommended system fits your household. A good solar company should ask for a recent electricity bill and discuss:

• Average daily consumption
• Daytime usage
• Evening and overnight demand
• Seasonal changes
• Air-conditioning use
• Pool or spa equipment
• Electric hot water
• EV charging
• Future plans to replace gas appliances
• Whether battery storage is being considered

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A standard package may be convenient to sell but might not suit your home's power use. A household using most electricity during daylight hours can get strong value from solar alone. A home that exports large amounts of solar during the day and buys power at night may benefit from battery storage.

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System size should also account for future needs. Solar panels can operate for decades. A system designed only for today’s usage may become inadequate when you add an electric vehicle, heat-pump hot water, or more air conditioning. Ask each company to explain how your bill and consumption pattern led to the recommended system size. If the answer is only that it is the company’s most popular package, the system may have been designed around their sales process rather than your home.

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2. Are the Exact Equipment Models Listed?

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A quote should identify the exact:

• Solar panel manufacturer and model
• Number of panels
• Total panel capacity
• Inverter manufacturer and model
• Inverter capacity
• Battery manufacturer and model
• Number of battery modules
• Battery controller or energy gateway
• Mounting system
• Monitoring platform

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A brand name alone is not enough. Manufacturers sell multiple product ranges with different capacities, features, warranties, and prices. For example, “Jinko panels” does not identify the exact panel supplied. “Sigenergy battery” does not specify the battery module size, total configuration, inverter, or backup equipment. Model numbers let you verify product approvals, specifications, and warranty documents. They also prevent substitutions between the quote and installation. Retailers reserve the right to replace equipment with an “equivalent” product. Ask how equivalence will be determined and if you must approve any substitution before installation.

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3. Do the Panel and Inverter Sizes Make Sense Together?

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Solar quotes can describe system size in ways that confuse homeowners. Total panel capacity is the combined rated output of the panels. The inverter has its own capacity, often lower than the total panel capacity. For example, a 6.6kW solar system may use about 6.6kW of panels with a 5kW inverter. This does not mean the system is incorrectly designed. Australian systems often have more panel capacity than inverter capacity to increase daytime generation. The quote should clearly distinguish between:

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• Total panel capacity
• Inverter capacity
• Expected annual generation
• Network export limit

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Ask why the proposed ratio was selected and whether the inverter allows enough flexibility for future solar or battery expansion. A larger panel array does not mean you can export all that power to the grid. Distribution networks may limit export capacity. However, the household can still use extra solar directly or store it in a battery.

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4. Is the Expected Solar Production Realistic?

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A solar quote should include a site-specific estimate of how much electricity the system is expected to generate. That estimate should account for:

• Geographic location
• Roof direction
• Roof pitch
• Shading
• Panel layout
• System losses
• Panel and inverter capacity
• Local weather patterns

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Be cautious of savings claims based only on the maximum system rating or an ideal sunny day. A 10kW system does not generate 10kW continuously from sunrise to sunset. Production varies during the day and changes with weather, season, panel temperature, orientation, and shading. The quote should separate electricity generation from financial savings. A system may produce substantial energy but deliver lower savings if most electricity is exported at a low feed-in tariff instead of used at home.

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Ask to see:

• Estimated annual generation in kWh
• The assumed self-consumption rate
• The assumed feed-in tariff
• The assumed grid electricity rate
• Expected annual bill reduction
• Whether electricity price increases have been included

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5. If a Battery Is Included, Is the Capacity Total or Usable?

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Battery size is an area where quotes may seem similar but produce different results. A battery may have:

• Total or nominal capacity
• Usable capacity
• A minimum operating reserve
• A separate backup reserve
• Different charge and discharge limits

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Usable capacity is the stored electricity available to power your home under the manufacturer’s conditions. If a quote advertises 15kWh of storage, ask if the full 15kWh is usable. Also ask how much remains for bill savings when part of the battery is reserved for blackouts. Capacity is not the same as power output. A large battery may store plenty of energy but cannot run several high-demand appliances at once.

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Ask the company to state:

• Total battery capacity
• Usable battery capacity
• Continuous power output
• Peak or surge output
• Minimum reserve
• Backup reserve
• Expected evening coverage based on your usage

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Our guide to choosing the right solar battery explains these specifications in more detail. This lets you compare the assumptions behind each company’s promised returns.

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6. Is Blackout Backup Actually Included?

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One common misunderstanding is assuming every solar battery powers the home during an outage. They do not. Standard grid-connected solar systems shut down during a blackout to prevent electricity from flowing into power lines while crews repair them. A battery needs compatible backup functionality and the correct electrical setup to supply the home safely.

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Backup may require:

• A compatible gateway
• Additional switchgear
• A backup sub-board
• Essential circuits to be separated
• Switchboard upgrades
• Additional installation labour

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Some quotes include this work. Others list a backup-capable battery but exclude the equipment needed to activate it. Ask each installer:

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• Is blackout backup included in this price?
• Which circuits will remain powered?
• Can the system support air conditioning, pumps or electric cooking?
• Will solar continue charging the battery during an outage?
• Is the backup single-phase or three-phase?
• How much battery capacity will be held in reserve?
• What happens when the battery becomes depleted?

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Whole-home backup does not mean unlimited power. The battery must have enough stored energy and output to support the appliances running at that time.

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7. Have Switchboard and Site Requirements Been Included?

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The equipment price is only part of the installation cost. Your switchboard may need work before the solar or battery system can be connected safely and compliantly. Older homes may have outdated protection, limited space, unsuitable wiring, or components that need replacing.

Other site costs may include:

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• Switchboard upgrades
• Metering changes
• Long cable runs
• Difficult roof access
• Scaffolding
• Tile replacement
• Multiple roof faces
• Trenching
• Bollards or impact protection
• Additional battery clearances
• Asbestos-related precautions
• Network applications
• Travel to regional properties

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Ask whether the quote is fixed or depends on a site inspection. If extra charges apply, the quote should explain what triggers them. A very low quote may exclude work another installer included. This does not always make the lower quote misleading. Some site conditions cannot be confirmed until inspection. The key issue is whether the company explained this uncertainty before you commit.

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8. Who Will Physically Complete the Installation?

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The company selling the system is not always the one installing it. Many solar retailers use contractors. This does not mean workmanship will be poor. Experienced, well-supervised contractors can complete excellent installations. However, you should know:

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• Who is responsible for the sale
• Who designs the system
• Who completes the installation
• Who supervises the work
• Who signs off the system
• Who you contact if there is a problem

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For systems to meet relevant incentive requirements, the work must be completed or supervised by people with the appropriate accreditation. Solar Accreditation Australia provides accreditation for grid-connected solar, battery and stand-alone power systems.

Solar and battery accreditation are not necessarily the same. If your quote includes a grid-connected battery, confirm the person responsible holds the appropriate battery accreditation. You can check an installer’s status through the Solar Accreditation Australia register. The quote should also identify the retailer’s responsibility after installation. You should not be passed between the salesperson, subcontractor, and manufacturer when something goes wrong.

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9. Are the Products Approved for Australian Installations?

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The quoted equipment should meet Australian requirements and appear on approved product lists. Installers claiming Small-scale Technology Certificates must have accreditation and use approved equipment, according to the Clean Energy Regulator.

Ask the company to confirm:

• The exact panels are approved
• The inverter is approved
• The battery is approved
• The equipment is suitable for Australian conditions
• The installation will qualify for the stated incentive
• The products supplied will match the models on the quote

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A low price isn’t useful if the system can’t receive the advertised incentive or if the equipment is substituted with a different model. Product approval confirms the equipment meets requirements but does not guarantee a good installation. The system design and workmanship determine how safely and effectively the products work together.

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10. What Do the Warranties Really Cover?

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A solar-and-battery system may include several separate warranties:

• Solar panel product warranty
• Solar panel performance warranty
• Inverter warranty
• Battery product warranty
• Battery retained-capacity warranty
• Mounting-system warranty
• Installation or workmanship warranty
• Retailer support commitments

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These warranties do not all provide the same protection. A panel performance warranty may promise the panel retains a percentage of its original output after a set period. This differs from a product warranty covering physical or manufacturing failure. Battery warranties may include conditions such as:

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• Years of operation
• Energy throughput
• Cycle count
• Retained capacity
• Operating temperature
• Internet connectivity
• Approved operating modes
• Installation requirements

Ask who pays for:

• Fault diagnosis
• Site attendance
• Labour
• Removal
• Freight
• Replacement installation
• Recommissioning

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A manufacturer may supply a replacement component but leave the homeowner responsible for labour and call-out costs. Consider whether the retailer will remain available to coordinate a claim. A 25-year product promise means less if no one accepts responsibility in year four. Stag Electrical’s warranty and workmanship protections provide customers a clear point of accountability beyond the equipment manufacturer.

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11. Are Rebates and Incentives Shown Clearly?

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Most people use the word “rebate,” but federal solar and battery incentives are generally delivered through Small-scale Technology Certificates rather than a cash payment made to the homeowner after installation. The estimated certificate value is commonly assigned to the retailer or an authorised agent and deducted from the upfront price.

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A quote should explain:

• The price before incentives
• The estimated certificate value
• The final price after incentives
• Which party creates or receives the certificates
• Any eligibility assumptions
• What happens if installation is delayed and the value changes

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For eligible batteries, the Cheaper Home Batteries Program applies through the Small-scale Renewable Energy Scheme. The incentive is based on usable battery capacity, subject to program limits and current calculation factors. The Clean Energy Regulator confirms that only the first 50kWh of a battery’s usable capacity can receive battery STCs. Since 1 May 2026, the applicable factor has also been tiered, with lower support applying to portions of capacity above 14kWh and 28kWh.

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This means the rebate shown for a larger battery should not simply be calculated by multiplying every kWh by the highest rate. Read our federal battery rebate guide for current program details. State loans, concessions and other programs may have additional eligibility requirements. Finance approval should also be separated from rebate eligibility. Being eligible for an incentive does not automatically mean a customer will be approved for a loan.

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12. What Happens After the System Is Installed?

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The relationship with your solar company should not end when the installation team leaves. Your quote or contract should explain what happens after installation, including:

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• System commissioning
• Monitoring app setup
• Customer handover
• Network approval
• Metering requirements
• Electrical documentation
• Product registration
• Warranty records
• Fault reporting
• Service and maintenance
• Expected response times

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Ask whether someone will show you how to:

• Check solar production
• Monitor grid imports and exports
• Review battery charging
• Change backup reserves
• Recognise error messages
• Contact support

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A system can be generating electricity while still underperforming. Monitoring access lets you spot changes before months of potential savings are lost. After-sales support matters because solar systems are designed to operate for decades. Inverters may report errors, monitoring connections can fail, batteries require software support and household electricity needs can change. The cheapest quote on installation day may not provide the best value over the system’s operating life.

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How to Spot Solar Quote Red Flags

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No single issue means you should avoid a company, but be cautious if you encounter several of the following:

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• Pressure to sign immediately
• A discount that expires within hours
• No request for an electricity bill
• No discussion of when you use power
• Equipment brands listed without model numbers
• Battery capacity shown without usable capacity
• Savings promised without explaining the assumptions
• Blackout protection implied but not itemised
• Switchboard work excluded without explanation
• No clear answer about who completes the installation
• Accreditation details cannot be verified
• Warranty coverage is described only verbally
• The quote relies on “equivalent products”
• Finance repayments are emphasised, but the total cost is hidden
• The rebate is described as guaranteed without eligibility conditions
• The company cannot explain who handles problems after installation

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A professional solar quote should make the decision clearer and avoid relying on urgency or confusion.

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How to Compare Three Solar Quotes Properly

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Place the quotes side by side to compare each of these items:

System Design

• Total panel capacity
• Inverter capacity
• Expected annual generation
• Panel placement
• Shading assumptions
• Current and future electricity needs

Equipment

• Exact panel model
• Exact inverter model
• Exact battery model
• Usable battery capacity
• Battery output
• Monitoring system

Installation

• Switchboard work
• Roof access
• Mounting system
• Backup equipment
• Additional circuits
• Network applications
• Site-specific exclusions

Protection

• Product warranties
• Performance warranties
• Battery capacity warranty
• Workmanship coverage
• Labour and call-out costs
• After-sales support

Financial Assumptions

• Price before incentives
• Incentive amount
• Final installed price
• Finance term and total repayment
• Electricity rate used
• Feed-in tariff used
• Self-consumption estimate
• Projected annual savings

When these details align, the final price makes sense.

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Questions to Ask a Solar Salesperson Before Signing

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Before accepting a quote, ask:

1. How did you calculate the recommended system size?
2. What exact panel, inverter and battery models will be installed?
3. What is the difference between panel capacity and inverter capacity?
4. How much electricity is the system expected to generate annually?
5. What electricity price, feed-in tariff and self-consumption rate were used?
6. If a battery is included, what is its usable capacity?
7. What continuous and peak output can the battery deliver?
8. Is blackout backup included, and which circuits will operate?
9. Does my switchboard need to be upgraded?
10. Are all expected installation costs included?
11. Who will physically install and supervise the system?
12. Can I verify their solar or battery accreditation?
13. Who handles faults and warranty claims?
14. Are labour and call-out costs covered?
15. What happens if the equipment becomes unavailable?
16. What documents and monitoring access will I receive?
17. How was the rebate or STC value calculated?
18. What could cause the final price to change?

The quality of the answers can tell you as much as the quote itself.

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Should You Always Choose the Most Expensive Solar Quote?

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No. A higher price doesn’t guarantee better equipment, workmanship, or service. The goal is to choose the quote offering the clearest, most suitable complete system at a fair price. A less expensive system may offer excellent value when:

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• The design suits your usage
• The equipment is appropriate
• All required work is included
• Warranty protection is clear
• The installer is properly qualified
• Savings estimates are realistic
• After-sales support is available

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Likewise, a premium quote should explain what the extra cost covers. This may include better equipment, more complex design, stronger backup, switchboard work, difficult access, longer protection, or higher installation standards. If a company cannot explain the difference, do not choose it based on price.

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Compare the Complete System, Not Just the Bottom Line

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A solar quote is more than a list of panels and a final price. It is a proposal for an electrical system that may operate on your home for 20 years or more. The strongest quote should show the company understands your property, electricity usage, and future plans. It should identify the exact equipment, explain expected performance, disclose exclusions, and clarify responsibility if something goes wrong.

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Most importantly, it should give you enough information to make a calm, informed decision without pressure or guesswork. At Stag Electrical, qualified electricians design every system around the property and household’s actual energy usage. Our installation process follows defined quality and installation standards, with clear equipment specifications, warranty protection, and long-term accountability.

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If you want to compare a Stag Electrical proposal with another quote, send us the details. We will explain the differences in plain English and show you what is included before you decide. Request a tailored solar and battery quote based on your home, power bill and future energy needs.

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Frequently Asked Questions About Comparing Solar Quotes

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How Do I Compare Solar Quotes Properly?

Compare the complete system, not just the final price. Check the exact panel, inverter, and battery models; system capacity; expected production; installation inclusions; switchboard work; warranties; installer accreditation; rebate calculations; and after-sales support.

Why Are Some Solar Quotes Much Cheaper Than Others?

A cheaper quote may use different equipment, include less installation work, or exclude switchboard upgrades, backup hardware, and other site costs. The system may have lower usable battery capacity or weaker warranty protection. Ask the company to explain every inclusion and potential additional charge.

What Information Should a Solar Quote Include?

A complete solar quote should identify exact equipment models, number of panels, panel and inverter capacities, expected annual generation, battery specifications, installation requirements, warranties, incentives, exclusions, and final installed price.

Should I Choose the Cheapest Solar Quote?

Not automatically. The cheapest quote may offer excellent value if it includes suitable equipment, professional installation, and clear warranty protection. However, compare all inclusions first to ensure you’re comparing equivalent systems.

How Do I Know Whether a Solar Quote Is Accurate?

The quote should be based on your electricity bill, household usage, roof layout, shading, phase configuration, and future energy needs. Savings estimates should disclose the electricity tariff, feed-in tariff, solar production, and self-consumption assumptions.

Should the Solar Quote List Exact Model Numbers?

Yes. The quote should identify the exact panel, inverter, battery, and supporting equipment models. This allows you to verify specifications, approvals, and warranties while reducing the risk of receiving a different product at installation.

What Is the Difference Between Panel Capacity and Inverter Capacity?

Panel capacity is the combined rated output of all solar panels. Inverter capacity is the power the inverter can convert at one time. Total panel capacity is often higher than inverter capacity, but the quote should clearly explain both figures.

What Should I Check When Comparing Solar Battery Quotes?

Compare usable capacity, continuous output, peak output, inverter compatibility, backup capability, phase configuration, expandability, and warranty conditions. Confirm whether the battery gateway, backup circuits, and switchboard work are included.

Does Every Solar Battery Include Blackout Backup?

No. A battery may support backup without the necessary gateway, switchgear, or electrical work included in the quote. Ask which circuits will remain powered, whether solar can recharge the battery during an outage, and what additional equipment is required.

Should Switchboard Upgrades Be Included in a Solar Quote?

If the company knows an upgrade is required, it should be clearly included or itemised. When switchboard condition cannot be confirmed before inspection, the quote should explain that extra costs may apply and what might trigger them.

How Do I Check Whether a Solar Installer Is Accredited?

Ask for the name and accreditation number of the person responsible for designing, installing, or supervising the system. You can check their current accreditation through Solar Accreditation Australia. Battery installations require the appropriate battery accreditation.

What Solar Warranties Should I Compare?

Compare panel product and performance warranties, inverter warranties, battery product and retained-capacity warranties, mounting-system warranties, and workmanship coverage. Check whether labour, call-outs, freight, removal, and reinstallation are covered.

How Should Solar Rebates Appear on a Quote?

The quote should show the price before incentives, the estimated certificate value, and the final price after the discount. It should also explain eligibility conditions and what happens if the incentive value changes before installation.

Can a Solar Company Change the Equipment After I Sign?

The contract may allow substitutions if the quoted equipment becomes unavailable. Check how an “equivalent” product is defined and whether you must approve the replacement. Any substitute should provide comparable specifications, quality, and warranty protection.

What Are the Biggest Red Flags in a Solar Quote?

Warning signs include pressure to sign immediately, missing model numbers, unrealistic savings promises, unclear exclusions, no discussion of your electricity usage, unverifiable accreditation, and vague answers about warranties, backup power, or additional costs.

How Many Solar Quotes Should I Get?

Three detailed quotes are generally enough to compare equipment, pricing, installation standards, and support. Collecting too many can make the decision more confusing, especially when the companies recommend systems based on different assumptions.

What Should I Ask Before Signing a Solar Quote?

Ask how the system was sized, what equipment will be installed, who will complete the work, whether all electrical upgrades are included, how savings were calculated, and who will assist if something fails after installation.

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