Installation
What a commercial solar installation actually involves
System sizes, real costs, and the six stages between sending a bill and generating power. Written for someone weighing up capital spend, not someone browsing panels.
Not a bigger house job
Why a commercial install is a different job
A commercial installation is a different job to a residential one, and the difference isn't just scale. Commercial roofs are usually metal deck or membrane rather than tile, the height-safety requirements are stricter, the switchboard work is three-phase, and the grid connection goes through an approval process that a household system skips entirely.
That's why the cost per kilowatt doesn't drop as fast as people expect when you go from a 10kW home system to a 100kW commercial one, and why the timeline is measured in months rather than weeks. Most of that time isn't work. It's waiting on a distributor.
Indicative ranges
System sizes and what they cost
Three tiers covering most commercial sites. Every figure is a range, because a straightforward metal-deck warehouse and an awkward multi-level retail building don't cost the same to fit out.
| System | Roof area | Installed | Saved a year | Payback |
|---|---|---|---|---|
| 30 kW~54 panels | 150 to 190 m² | $28,000 to $38,000 | $7,000 to $11,000 | 2.8 to 4.1 years |
| 50 kW~90 panels | 250 to 320 m² | $44,000 to $58,000 | $12,000 to $18,000 | 2.6 to 3.8 years |
| 100 kW~180 panels | 500 to 620 m² | $82,000 to $110,000 | $24,000 to $36,000 | 2.5 to 3.6 years |
Ranges, not quotes. These are example figures, not our prices or a quote. Roof type, switchboard condition, network approval and how much of your load falls in daylight hours move every one of these numbers. The proposal you get back replaces this table with figures for your site. It shows the STC discount, the federal upfront price reduction, as its own line (Small-scale Renewable Energy Scheme, Clean Energy Regulator, checked 23 October 2026).
What's in the price
What isn't
What moves the number most
The process
The six stages, with honest timings
Roughly three to five months from first bill to a commissioned system, on a job with no complications. Here's where that time goes.
- 012 to 3 days
Bill review and system sizing
Your consumption gets mapped against a generation profile for your postcode and roof orientation. The output is a kilowatt figure and a first pass at the economics. - 02Within a week
Site assessment
Roof structure, sheeting type and age, switchboard capacity, available space, shading and how the cable run would work. Some of this is done on satellite imagery, the rest needs someone on site. - 033 to 5 days after the site visit
Written proposal
Equipment, layout, generation estimate, cost after STCs, saving, payback and the assumptions behind all of it. Nothing hidden in a footnote. - 042 to 8 weeks
Network application
Your distributor decides whether the system can connect at the size proposed and what your export limit will be. This is the stage nobody can speed up, and any installer promising otherwise is guessing. - 052 to 5 days on site
Installation
Mounting, panels, cabling, inverters, then the switchboard tie-in. One short planned outage. Height safety and traffic management get organised before anyone goes up. - 061 to 4 weeks
Commissioning and meter change
Testing, inspection, paperwork to the distributor, and your retailer reconfigures the meter for a site that now exports. The system generates from day one, but the billing catches up here.
To start
What we need from you
Just your electricity bill. That’s it. Send one recent bill, every page. The pages most people skip carry your tariff, your rates and your demand charge, and the NMI (your meter’s ID).
We take it from there. Using the NMI on your bill, the team gets your interval data: your meter’s reading every half-hour, which shows exactly when your site uses power. You don’t need to request it or send anything else.
If you have plans that will change your power use, such as a new shift, a freezer room or an EV fleet, mention them in the form. Our guide on how to read a commercial electricity bill explains what’s on it.
Connection
Grid connection is the part that catches people out
Every commercial system needs permission from the business that owns the poles and wires in your area, and that business isn't your retailer. Below a threshold the application is fairly routine. Above it, your distributor assesses the feeder your site sits on and decides how much you're allowed to export.
On a constrained part of the network that can come back as a reduced export limit, or as zero export. A system can still be worth building with exports capped, because the value was mostly in offsetting what you buy rather than what you sell. But the payback maths changes, and any proposal worth reading shows you both versions.
Which distributor you're dealing with depends entirely on where the site is: Ausgrid or Endeavour Energy in Sydney, Ausgrid in Newcastle, Evoenergy in Canberra, Energex across south-east Queensland, Western Power in Perth, one of five networks in Melbourne, and SA Power Networks across South Australia.
How we're paid, and what you actually get
Commercial Solar Quotes reads your electricity bill, sizes a system against your actual consumption profile, and returns a costed proposal prepared by an accredited commercial solar installer we work with.
We don't run an auction and we don't publish a panel of competing quotes. You get one proposal, built for your site, with the assumptions shown so you can check them or take them to another installer.
The installer funds this service so that it's free to use. They pay us to run it, not per project and not out of your quote, so nothing about what we recommend changes what we're paid. You pay nothing for the assessment, and there's no obligation to accept the proposal.
Questions
Installation questions
How long does a commercial installation take?
The install itself is two to five days on site for a system between 30kW and 100kW. Getting to that point takes longer than the work does: network approval is usually the longest single wait, and on a constrained feeder it can run to several weeks on its own.
Does the business have to shut down during installation?
Almost never for the roof work. There's one short outage when the system is tied into your switchboard, usually under two hours, and it gets booked for whenever hurts least. A site running seven days gets it done overnight.
Who actually does the installation?
A Clean Energy Council accredited installer with commercial experience and their own licensed electricians. Roof work on a commercial building needs height-safety compliance and a different skill set to residential, which is why the residential price per kilowatt doesn't transfer.
What happens if the roof isn't suitable?
We tell you, and that's the end of it. Asbestos sheeting, a roof within a few years of replacement, or structural capacity that won't take the extra load are all reasons to stop. Finding that out during a free assessment costs you nothing. Finding it out after a deposit costs a lot.
Can we install in stages?
Yes, and it's often the right call when capital is tight or when a site's load is about to change. The thing to get right is designing stage one so stage two doesn't mean replacing the inverter and re-applying to the network.
Find out what your site needs
One recent bill is enough to size a system and price it. It costs nothing, and there's no obligation.
Send your bill