Reading a solar quote before you sign it

By Oliver Hill

Two quotes for the same system are rarely the same job

A quote that says 6.6kW and a price has told you almost nothing. It has not told you which panels, which inverter, what happens on your particular roof, what is excluded, or who comes back if something stops working in year four. Those are where the difference between two quotes usually lives.

What is actually specified

Ask for the panel model, the inverter model and, if storage is included, the battery model. Not the brand, the model. Brands sell several tiers, and the gap between the entry product and the premium one from the same manufacturer can be considerable.

Then check the inverter is sized sensibly for the array, and that both are on the approved lists for Australian installations.

Roof difficulty, and when the extra cost is fair

Some roofs genuinely cost more to work on. Tile takes longer than metal. Two storeys needs more equipment than one. Restricted access, which is common on the narrower blocks around Footscray, can mean gear has to be carried rather than driven in.

All of that can be legitimate. What you want is for it to be visible. A quote that separates site difficulty from equipment lets you compare two installers on the same terms. A quote that gives you one number does not.

Switchboard upgrades

Older boards sometimes need upgrading before a system can be connected, and post-war housing through Sunshine, St Albans and Niddrie is where this comes up most often. It is a real requirement and a real cost.

The thing to watch is not whether it is on the quote. It is whether it is on both quotes. If one installer has priced a board upgrade and the other has not, they have not quoted the same job, and the cheaper one may simply have deferred the discovery until they are on site. Ask each of them directly whether your board needs work and what they have allowed for it.

Metering, and who arranges it

A solar installation usually needs the meter reconfigured or replaced, which is arranged through your retailer. Ask who lodges that, whether any cost sits with you, and roughly how long it takes. It is a small thing that accounts for a surprising share of the gap between install day and the system actually working.

Backup, if a battery is included

Not every battery installation keeps your house running in a blackout, and the ones that do usually back up selected circuits rather than everything. If backup matters to you, ask which circuits, and confirm it is included in the price rather than available as an option.

The export limit they designed to

Your distributor sets how much you are allowed to export, and that limit shapes the design. Ask what limit the quote assumes and for which network. An installer who cannot answer that for your address is telling you something about how closely they have looked.

This matters more in the west than people expect, because network boundaries do not follow suburb boundaries and the answer is properly confirmed at address level rather than by suburb. Homes in Essendon and Point Cook sit in different networks with different rules.

Exclusions

Read what the quote says it does not include. Common ones are switchboard work, meter costs, rectifying existing wiring, and anything discovered once the tiles come off. None of those are unreasonable to exclude. All of them are unreasonable to discover on the day.

Ask for any exclusion that might apply to you to be priced as an option, in writing, before you accept. A number you have seen is not a surprise.

Warranty, which is two different things

Product warranty is the manufacturer's, and it covers the hardware. Workmanship warranty is the installer's, and it covers the installation. The second one is the one worth asking about, because it is only as good as the business standing behind it. Ask who attends a fault, whether there is a call-out fee, and what happens if the installing company is no longer trading.

Making two quotes comparable

Once you have the model numbers, the site work itemised, the exclusions priced and the export limit stated, the two quotes are finally describing the same job and the prices mean something. That is usually the point at which the cheaper one turns out to be cheaper for a reason, in either direction.

How I read a solar quote walks through a real quote line by line. The cheapest solar in Victoria covers what a genuinely low price does and does not buy.

Common questions