How to choose a commercial solar installer and compare quotes

A commercial quote is rarely one number you can compare to the next. One bidder includes grid protection and the network application, another leaves them out, and a third quotes a different system size. The fix is to control the inputs: write one brief, send it to three installers, and require each quote to state the same things.

This guide covers what to check on the installer, what the brief should contain, and what a comparable quote looks like. For pricing context, see our guide to what commercial solar costs.

What should you check on a commercial solar installer?

Start with accreditation. Solar Accreditation Australia accredits people as Design Only, Install Only, or Design and Install, across three technology classes: grid-connected solar (GCPV), grid-connected battery storage (GCBS) and stand-alone power systems (SPS). Battery storage is its own class, so a company installing solar and a battery should hold both. SAA’s page does not describe a separate category for commercial or over-100 kW work, so ask the installer directly about their experience at your size.

You can confirm a person’s accreditation on SAA’s accreditation status check. Our guide to checking a solar company’s accreditation walks through it, and the accreditation check tool does it from a name or number.

The Clean Energy Regulator’s transitional guidance for mid-scale solar confirms that product accreditation, installer accreditation and electrical safety rules still apply, and that mid-scale systems must use panels, batteries or inverters on the CEC list of approved components.

Does the consumer code cover business purchases?

The New Energy Tech Consumer Code covers solar, batteries, EV chargers and more, with standards for sales and marketing, quotes and contracts, installation, and warranties and support. The page we checked is written for consumers and does not say whether the Code applies to business or commercial customers, and it states no system-size limit. An updated version takes effect on 1 December 2026.

So the practical advice is to check whether the seller is a signatory (the Code’s Approved Seller list shows who is) and whether the Code covers your purchase. Ask the seller in writing. Our explainer on what an approved seller is covers what the Code does for households.

What evidence should a mid-scale installer keep?

Systems between 100 kW and 1 MW installed from 1 October 2026 can create small-scale technology certificates under the Clean Energy Regulator’s mid-scale rules, which we explain in our mid-scale solar guide. That brings paperwork duties that fall partly on the installer and partly on you.

According to the regulator’s guidance, accredited installers must keep photographs showing they attended the site for the final stage of installation and commissioning. The photos must be geotagged and time-stamped, clearly show the installer’s face, show the installed equipment (panels, inverter, switchboard, battery), show the system during testing and commissioning, and match the dates on the compliance certificates. Photos taken afterwards to recreate evidence may not be accepted, and applications can be rejected without it.

The business should also keep records throughout the project. The regulator lists:

• system design documentation
• network connection approvals (where applicable)
• planning and building approvals, and structural engineering reports where applicable
• metering information
• electrical compliance certificates
• testing and commissioning records
• photographs and installation evidence

Network approval has its own rules. The regulator requires evidence of network connection approvals where they apply, and each network sets its own process. Our guide to commercial solar grid connection explains the steps. Ask each bidder whether approval is needed before installation starts, because some networks want the application lodged and approved first.

How do you write one brief and get three comparable quotes?

Three installers given three different sets of facts will produce three different systems. Write one brief and send the same pack to each. Three bidders is usually enough: more adds work without adding information. If you want a hand, the business quote request collects these details in one form.

Then require every quote to state the same things. If a quote leaves one out, ask for it in writing before you compare prices.

Our guides on solar warranties and questions to ask before signing a quote go deeper on the warranty and contract details.

A worked example of an unlike-for-like comparison

This is an illustration with made-up quotes, not market prices. For scale, Solar Choice’s September 2026 price survey gives an average of $81,570 for a 100 kW system after certificates and including GST. That average excludes meter installation, ground-mounting, grid protection and grid connection studies, so bidders who include them will look dearer.

On headline price, B wins. Once its missing network costs are added (the $6,500 here is an assumption for the example; ask B for a firm figure), B comes to $85,500, and the gap with A is small. Only the written brief and the checklist make that visible.

When should you pause before choosing?

Also pause if your roof needs repairs soon, if your electricity use is mostly at night, or if you have not yet checked whether your network will let you export. Fix those first. A cheaper quote on the wrong system is not a saving.

If you are still deciding whether solar suits the business at all, our guide on whether commercial solar is worth it is the place to start.

This guide is general information, not financial or legal advice. Rules, rebates and prices change, so check the linked sources before you decide. Facts checked 31 October 2026.