How to compare solar quotations from different installers

Put every quotation on the same footing

Two totals mean nothing side by side if one installer quoted a larger system, a different system type or a narrower scope. Ask each installer to quote the same capacity and the same type, whether on-grid, off-grid or hybrid, so that you compare like with like.

If an installer proposes a different size, ask why and ask for a quotation at your size as well. A revision that matches the others is a normal request, and a good installer will not mind it.

Compare the bill of materials line by line

The bill of materials lists what you will actually receive. A vague line, such as inverter with no make or rating, cannot be compared with a precise one.

• Modules: the make, the model and the rating, and whether each module is DCR or non-DCR.
• Inverter: the make, the rating and, for a hybrid system, how it works with the battery.
• Mounting structure, cables and protection: what is supplied, so a cheaper total is not simply a thinner list.
• Battery, if any: its make, its capacity and whether it is priced as a separate line.
• Meter and grid connection items, if you plan net metering.

Find out what the total includes

Two quotations with the same equipment can still differ in what is left for you to pay later. Ask each installer to confirm, in writing, who handles each of these:

• Transport and installation, including any civil or structural work on the roof.
• The net metering application and any fee the distribution company charges.
• The subsidy application, if you want the subsidy.
• Tax: whether the total includes GST, and how it is shown on each line.
• After-sales visits and who you call if the system stops working.

Compare warranty and payment terms

Ask what each warranty covers, who honours it and how a claim is made. A warranty from the manufacturer and a service promise from the installer are different things, so check which one a quotation is offering.

Payment terms differ too. Compare how much is asked at each stage and what you receive at that stage, and be careful with any quotation that asks for most of the money before the work begins.

Read the subsidy line with care

A subsidy figure on a quotation is an estimate. The customer normally pays the installer the full amount and the government pays the subsidy afterwards, so one installer showing the price after subsidy and another showing it before subsidy are not comparable until you put them on the same basis.

Modules whose DCR status cannot be verified are not accepted under the schemes that require it, so check the module line before you trust any subsidy figure. Ask each installer to state the status in writing.

Step by step

1. 1

   Match the size and type

   Ask every installer to quote the same capacity and the same system type.

2. 2

   Compare the equipment lines

   Check the make, model and rating of each module, inverter and battery.

3. 3

   List what is included

   Write down who handles installation, applications, tax and after-sales visits.

4. 4

   Read the terms

   Compare the warranty, what each one covers and who honours it, and the payment stages.

5. 5

   Put the subsidy on one basis

   Compare every price before the subsidy, or every price after it, never a mix.

Common mistakes

• Comparing totals before the scope matches

  A smaller system or a narrower scope looks cheaper only because less is being supplied.

• Accepting a vague equipment line

  A line with no make, model or rating cannot be compared and invites disputes later.

• Mixing prices before and after the subsidy

  The subsidy is paid to the customer afterwards, so one price that deducts it and one that does not are not comparable.

• Assuming the warranty comes from the maker

  Check whether a warranty is the manufacturer's or only the installer's promise, and who honours a claim.

• Paying most of the money up front

  Compare what you receive at each payment stage, and be careful when most of the money is asked before the work begins.

What to check before you send

• Every quotation is for the same capacity and the same system type
• Each module, inverter and battery line names its make, model and rating
• Each quotation says whether the modules are DCR or non-DCR
• You know who handles the installation, the net metering application and the subsidy application
• The tax treatment is shown on each quotation and is the same basis across them
• The warranty says who honours it and how a claim is made
• You compared prices on the same subsidy basis

Sources

• MNRE: Approved List of Models and Manufacturers (ALMM), read 10 Oct 2026