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Commercial Solar Warranties: Panels, Inverters, Workmanship

Guide · Commercial solar & battery · ~5 min read

Warranties are where a lot of commercial solar deals quietly fall apart. Knowing the difference between a panel product warranty, a performance warranty, an inverter warranty and workmanship cover helps you buy on value, not just headline price.

The Three Warranties You're Actually Buying

Every commercial solar system comes with layered cover, and they don't all mean the same thing. Lumping them together is how facility managers get caught out when a fault appears years down the track.

Broadly, you're dealing with product warranties from manufacturers, performance warranties on panel output, and workmanship cover from whoever did the install. Each has its own term, its own exclusions and its own party responsible for honouring it.

• Product warranty: covers the physical panel or inverter against manufacturing defects.
• Performance warranty: guarantees panels keep producing above a stated output over time.
• Workmanship warranty: covers the quality of the installation itself, from mounting to cabling.
• Inverter warranty: often shorter than the panel term, so plan for it separately.

Panel Warranties: Product vs Performance

Panels typically carry two separate warranties, and they run for different lengths. The product warranty covers defects in the panel itself. The performance warranty is a promise that the panel will still generate above a certain level of its original output after a given number of years.

The catch is that panels naturally degrade over time. A performance warranty accounts for that expected decline, so it's not a promise of full output forever. Read how degradation is measured and what triggers a claim before you assume you're covered.

• Check whether the product and performance terms are the same length or differ.
• Understand the annual degradation the warranty allows for.
• Confirm the manufacturer has an Australian presence or support pathway.
• Ask who pays for freight and labour on a replacement panel, not just the panel itself.

Inverter and Battery Warranties

Inverters and batteries are the hardest-working parts of a system, and their warranties often run shorter than the panels'. That's worth budgeting for, because an inverter may need attention before the panels do.

If you're running AI-driven energy arbitrage, where the battery charges when power is cheap and discharges or exports when it's dear, the battery cycles more actively. Warranty terms on batteries frequently reference cycle counts or throughput, so match the warranty to how you actually intend to run the asset.

• Note the inverter term separately and plan for eventual replacement.
• Check battery warranties for cycle or throughput limits, not just years.
• Confirm the warranty holds up under the way you'll operate the system.
• Ask about firmware and monitoring support over the life of the unit.

Workmanship: The One People Overlook

You can buy the best panels on the market and still have a poor result if the install is sloppy. Workmanship warranty covers the labour and quality of the installation, from roof penetrations and mounting through to cabling, isolators and switchboard work.

This is where using an in-house team matters. At ATI we don't subcontract, so the people who install your system are the people accountable for it. We're CEC and SAA accredited, and that accountability runs from a 6.6kW rooftop through to MW-scale commercial jobs like the 415kW rooftop at DB Santasalo in Bulli.

• Ask whether the installer uses subcontractors or their own crew.
• Confirm CEC and SAA accreditation.
• Check the workmanship term and what specifically it covers.
• Ask what happens to warranty support if the installer changes hands.

Reading the Fine Print Before You Sign

The exclusions and conditions decide whether a warranty is worth anything. Common gotchas include claims that require professional cleaning records, exclusions for certain roof types or environments, and terms that cover parts but not the labour to fit them.

For commercial sites, also think about who remains responsible over the life of the system and how claims are actually lodged. A warranty is only real if there's someone still around to honour it and a clear process to make a claim.

• Separate parts-only cover from parts-and-labour cover.
• Note any maintenance or cleaning conditions that could void a claim.
• Check for site or environment exclusions relevant to your location.
• Understand the claims process and expected turnaround.

Get the Warranty Picture for Your Site

Warranty terms mean different things depending on your roof, your equipment choice and how hard you'll run the system. The only way to know what you're really covered for is to look at the specifics.

If you'd like a clear read on the warranties across panels, inverters, batteries and workmanship for your building, a site review is the practical next step. We'll walk you through what's covered, for how long, and who stands behind it.

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