Solar Warranties Explained: What to Look For Before You Buy

Panel warranties: two promises, not one

Solar panels come with two distinct warranties, and confusing them is the most common warranty mistake buyers make.

The product warranty (sometimes called the materials or manufacturing warranty) covers the panel physically failing — a defect in the build, delamination, a junction box fault. If the panel itself breaks through no fault of yours within this period, it is covered. Quality panels typically carry a product warranty of well over a decade.

The performance warranty (or power output warranty) is different. It guarantees the panel will still produce at least a stated percentage of its original output after a set number of years, usually around 25. This exists because all panels degrade slowly over time. The warranty promises that degradation will stay within acceptable limits — so if your panel is producing far less than it should after ten years, you have a claim.

When you compare panels, check both numbers. A panel with a longer product warranty and a higher guaranteed output percentage at the 25-year mark is a stronger long-term bet, even if two panels look identical on their power rating today.

Inverter warranties: the hard-working brain

The inverter runs every day, converting and managing power between your panels, battery, home and the grid. Because it works so hard, its warranty tends to be shorter than the panels' — often in the range of a decade, sometimes extendable.

Two things are worth checking here. First, the length: an inverter is one of the components you may replace during the system's life, so a longer warranty genuinely reduces your risk. Second, whether the warranty is extendable, as some quality brands like Sunsynk let you add years for a fee, which can be worth it on the component most likely to need attention. Ask your installer what the standard term is and whether an extension is available.

Battery warranties: read both numbers

The battery warranty is the one that trips people up most, because it is usually stated in two ways at once, and either can run out first.

The first figure is a time period — a number of years of cover. The second is a throughput or cycle limit — the total amount of energy the battery is guaranteed to deliver over its life, often expressed in megawatt-hours or a number of charge cycles. Your warranty lasts until you hit either limit.

This matters enormously in South Africa. A battery that is cycled hard every single night through relentless load-shedding will reach its throughput limit faster than the same battery in a home that rarely loses power. So the "10-year" battery warranty you saw on the brochure might, in a high-outage household, actually expire on throughput several years earlier. Read both numbers, and be realistic about how hard your battery will work. It is also worth checking the guaranteed retained capacity at end of term — like panels, batteries hold less charge as they age, and a good warranty states how much capacity you are guaranteed to keep.

Workmanship: the warranty on the install itself

Here is the guarantee that gets forgotten, and it is one of the most important. Even the best components will fail early if they are badly installed — water pooling from poor mounting, loose connections, undersized cabling, an inverter starved of airflow. None of that is covered by the manufacturers' component warranties, because it is not the components' fault.

That is what the workmanship guarantee is for. It is the installer's promise to stand behind the quality of their own work for a period after installation. A confident, established installer offers a meaningful workmanship guarantee; a fly-by-night operator offers little or none, because they may not intend to be around to honour it. Always ask what the workmanship guarantee covers and for how long — it is a direct signal of how much the installer trusts their own work.

The fine print that actually bites

Beyond the headline years and percentages, a few details in the terms decide whether a claim is smooth or a nightmare.

Who handles the claim? With a good installer, they manage the claim with the manufacturer on your behalf. With a cheap importer, you may be left to deal with an overseas manufacturer yourself. This alone is a strong reason to buy from an accountable local company.

Are labour and shipping covered? A component might be replaced free, but if you are paying for the technician's time and the freight to get the part, a "free" replacement is not free.

What voids the warranty? DIY tampering, unqualified repairs, or non-compliant installation can all void cover. This is another reason to use a professional, compliant installer from the start.

Is the company likely to still exist? A 25-year warranty from a supplier who disappears in three years is worthless. Buy panels from established manufacturers and systems from an established installer.

This is exactly why buying a properly packaged system from an accountable installer beats assembling bargain parts. When you take a package from a company like Alumo, the panels, inverter and battery are quality-matched components with their manufacturer warranties, installed under a workmanship guarantee, with the installer standing between you and the manufacturers when something needs fixing.

For a household that wants more resilience and a larger battery, the same warranty principles apply — just make sure the bigger battery's throughput terms match how hard you will actually cycle it through load-shedding.

Before you sign anything, ask for every warranty document in writing and read the four guarantees — panel product, panel performance, inverter, battery — plus the workmanship terms. If a quote is vague about any of them, treat that as a warning. Get a free quote → to see a system where the warranties are spelled out and the installer handles the claims.

Frequently asked questions

How many warranties does a solar system have?

Typically four: a panel product warranty, a panel performance warranty, an inverter warranty and a battery warranty, plus the installer's workmanship guarantee on the installation itself. Each has its own duration and terms.

Why does my battery warranty have two numbers?

Because it is limited by both time and total energy throughput (or cycles), and it expires when you reach either one first. A battery cycled hard through frequent load-shedding can hit its throughput limit before its year limit, so read both.

What is a workmanship guarantee and why does it matter?

It is the installer's promise to stand behind the quality of their installation for a set period. Component warranties do not cover installation faults like poor mounting or loose wiring, so a strong workmanship guarantee protects you where the manufacturer warranties do not.

Are labour and shipping included when a part is replaced under warranty?

Not always — check. Some warranties cover only the part, leaving you to pay for the technician's labour and freight. An accountable local installer who manages the claim end to end saves you both cost and hassle.

Does using an unqualified installer affect my warranty?

Yes. Non-compliant installation, DIY tampering or unqualified repairs can void component warranties. Using a professional, compliant installer protects your cover and is required to keep the guarantees valid.

SolarGuide is an independent referral partner. Alumo supplies, installs, finances and warrants the systems; SolarGuide helps you compare and get a free quote. Pricing is indicative and subject to a site assessment and credit approval.