How to compare solar quotes properly.

What is the best way to compare solar quotes?

Put every quote into the same comparison table and separate four things: system design, equipment, installation scope and financial assumptions. Only then compare the final price.

A cheaper quote may genuinely be better value. A more expensive quote may include a larger inverter, stronger backup, difficult roof work or switchboard upgrades. The problem is not a low or high price. The problem is comparing different scopes as if they were identical.

Start with array size and inverter size

Record the panel array capacity in kW DC and the inverter capacity in kW or kVA AC. Those numbers may legitimately differ.

Then ask why that size was recommended. A credible explanation should connect the design to your electricity use, roof, shading, expected future loads and network approval rather than simply offering the retailer's standard package.

Use the Melbourne Solar Guide calculator to establish a sizing starting point ↗

Compare exact product models, not just brand names

Write down the full panel, inverter and battery model numbers. One manufacturer can sell multiple product families with different efficiencies, warranties, backup features and operating limits.

Use the equipment reference when checking unfamiliar brands and configurations ↗

For batteries, compare usable kWh and output kW separately

Nominal battery capacity is not enough. Record the usable capacity in kWh and continuous output power in kW. A large energy store can still be unable to run several high-power loads at once.

Backup also needs its own row. Check whether backup hardware is included, which circuits remain powered, the available backup power and whether solar can recharge the battery during an outage.

See the battery sizing guide ↗

Compare the physical installation scope

Quotes can differ because the proposed work differs. Record any allowance for switchboard changes, long cable runs, difficult roof access, multiple roof faces, tile replacement, consumption monitoring, additional protection equipment and network-control hardware.

Also check what is expressly excluded. An exclusion is not automatically unreasonable, but it should be visible before you sign rather than appearing as a surprise variation later.

Separate product warranties from workmanship support

Panel product warranties, panel performance warranties, inverter warranties, battery warranties and workmanship warranties protect different things. Record the term and the party responsible for each one.

Ask who you contact first if the system fails and whether labour, freight or access costs can fall outside the written warranty. Your Australian Consumer Law rights sit alongside voluntary warranties.

Read the solar warranty guide ↗

Compare the money on the same basis

For each proposal, record the gross installed price, each certificate or rebate deduction and the final amount payable. If finance is used, compare the total amount repaid rather than only the weekly or monthly repayment.

Check whether the quote assumes STCs, a Solar Victoria rebate, a federal battery discount or another incentive. If eligibility is uncertain, ask what happens to the contract price if the incentive cannot be claimed.

See the Melbourne solar price framework ↗

Do not compare projected savings until you compare the assumptions

A savings estimate can change dramatically with the import tariff, export rate, self-consumption percentage, battery cycling, degradation and assumed future electricity use.

Ask the retailer to state the import rate, export rate, annual generation, expected self-consumption and any network export limit used in the model. If two quotes predict very different savings from similar hardware, the assumptions are the first place to look.

Solar quote comparison table

Use the table below for two or three quotes. Melbourne Solar Guide can later turn the same structure into an interactive quote-comparison tool without changing the underlying decision framework.

DOWNLOAD THE COMPARISON TABLE