CEC Guidelines for Grid-Connected Solar: What a Compliant Sydney Installation Looks Like

If you've collected a few solar quotes lately, you'll know they can look almost identical: similar panels, similar inverter, similar price. The difference between a great system and a future headache usually isn't on the quote at all — it's in whether the installer actually follows the Clean Energy Council (CEC) guidelines and the Australian Standards behind them. Here's what compliance genuinely looks like, so you know what to ask.

Who's allowed to install solar in the first place

For your system to earn small-scale technology certificates (STCs) — the federal rebate that knocks thousands off the price — it must be installed by an accredited person under the CEC's accreditation scheme. Accreditation isn't a one-off certificate either: accredited installers are bound by a code of conduct, must complete professional development every year, and can have their accreditation suspended or cancelled if their work doesn't stack up. So "are you accredited, and in whose name will this system be signed off?" is the first question worth asking.

The installer has to actually be there

This is the requirement most homeowners have never heard of. Under the CEC guidelines, the accredited person must either do the installation or genuinely supervise it — and supervision is defined as attending site during job set-up, a mid-installation check, and the final testing and commissioning. The guidelines also cap how many systems one accredited person can sign off in a day: no more than two complete installations. That cap exists because "drive-by sign-offs", where an accredited name appears on paperwork for a job they barely saw, were a real industry problem. If the person on your quote won't be on your roof, ask who will be — and when.

Design details that separate good from average

A compliant designer has to give you more than a brochure. The CEC guidelines require full system specifications — make, model and quantity of panels and inverter — plus a site-specific design that accounts for shading, orientation and tilt, and an estimate of average daily energy yield for each month of the year. The mounting system has to be designed to the wind loading standard (AS/NZS 1170.2), and the inverter has to be matched to the array: its nominal AC output can't be less than 75 per cent of the array's peak power, and the array can't exceed the inverter manufacturer's maximum allowable size.

The physical install: small things that matter for decades

On the roof, compliance shows up in unglamorous details. Cable and conduit passing through a tile or steel roof needs a fit-for-purpose collar flashing — not a blob of silicone. Tiles must sit flat after mounting brackets go in, which sometimes means grinding the underside of a tile so it keeps its original weatherproofing. There should be enough clearance under the array for the roof to self-clean, and in leafy or possum-prone parts of Sydney it's worth discussing how to keep fauna out from under the panels. None of this affects day-one performance — all of it affects whether your roof leaks in year six.

Switch-on is a test procedure, not a ceremony

AS/NZS 5033 — the standard for PV array installation — sets out mandatory commissioning tests before a system goes live: continuity of string and earth connections, voltage and polarity checks on every string, insulation resistance testing of the array wiring, and confirming the DC isolator safely disconnects the array under load. The results get recorded, and the standard also requires a written shutdown procedure displayed at the equipment — including the warning that switching a DC isolator off does not de-energise the panels and their cables while the sun is up. That's information your family and any future tradie on site genuinely need.

Before the installer leaves, you should be handed a system manual: equipment list with serial numbers, system connection diagram, shutdown and isolation procedure, performance estimate, maintenance schedule, commissioning records and warranty details. Electronic copies are fine — but no documentation is a red flag, and it will matter when you sell the house or make a warranty claim.

The takeaway

A compliant solar installation is the product of an accredited installer who was actually on site, a design done for your roof rather than a template, and a commissioning process with recorded test results and proper handover documents. If a quote can't demonstrate those things, the cheap price is borrowing against your future roof. High Demand Electrical works alongside CEC-accredited installers and handles the Level 2 and metering side of solar connections across Sydney — if you want a second opinion on a quote or a compliance check on an existing system, we're happy to take a look.