When should you get a solar thermal inspection?

Thermal inspections use infrared cameras to identify hotspots, cell damage, and wiring faults that are invisible to the naked eye. Not every system needs one — but some definitely do. Here are the signs that indicate a thermal inspection is worth the investment.

Symptoms to watch for

Signs that this issue may be affecting your system

Cell hotspots

Common

Localised overheating in individual cells caused by micro-cracks, shading, or manufacturing defects. Best detected via thermal imaging.

Loss: 520%Detection: thermal

Wiring or connection issues

Uncommon

Loose connectors, corroded terminals, or damaged wiring causing resistive losses. Can be a fire risk if severe.

Loss: 320%Detection: electrical

When to get a professional inspection

Signs you need professional help

-Your system is over 7 years old and you've noticed a production decline
-Production has dropped more than 1% per year compared to year one
-Your system has experienced hail, storms, or physical damage
-You see visible damage: discolouration, bubbling, or cracked glass
-Your inverter shows frequent error codes or unexpected shutdowns

Expected inspection costs

Drone thermal audit

Most comprehensive option

Handheld thermal scan

Best for smaller systems

Electrical inspection

Inverter and wiring only

Find inspection providers

Browse providers — US · UK · Australia · Spain

Is your system affected?

Use our free Solar Loss Checker to get a personalised diagnosis with an action plan.

Based on conservative solar performance modelling and published degradation data

NRELIEA-PVPSSunSpecPVsyst+ published research

Updated June 2026 · Structured performance modelling

How we calculate →

More guides

Solar inspection by region

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When should you get a solar thermal inspection? — By State

Frequently asked questions

How much performance loss is typical for this solar problem?+

Cell hotspots typically causes 5–20% output loss on residential solar systems, depending on severity, panel count affected, and how long the defect has been present.

Can I detect this issue without a professional inspection?+

Some signs (visible discolouration, hot panels on a clear day, inverter error codes, year-on-year kWh drop > 8%) are observable from monitoring data. For confirmation, a thermal imaging inspection — drone or handheld FLIR — is the gold standard and costs $299–$549 for a residential system.

Is this covered under my panel or inverter warranty?+

Most tier-1 panel warranties cover defects causing performance below 80–85% of nameplate within 25 years, and inverter warranties run 10–12 years. Claims almost always require third-party diagnostic evidence (thermal images, IV-curve traces, or written performance reports).

How fast does this defect get worse if I ignore it?+

Untreated, cell hotspots can compound — a single hot cell can degrade neighbouring cells through reverse bias, and a failing optimiser or inverter often cascades across strings. Typical degradation acceleration is 2–4× normal once a fault is present.

What does a thermal inspection cost to confirm this?+

A residential thermal solar inspection in the US costs $299–$549, UK £249–£449, and Australia AU$399–AU$699. Drone-based audits are usually at the lower end and complete a 10 kW array in under 20 minutes.

Should I repair, replace, or claim warranty?+

Rule of thumb: if defect-affected panels represent < 10% of array output, repair (e.g. bypass diode replacement, junction box rework). If 10–25% and within warranty period, file a claim. If > 25% and out of warranty, model the payback of partial re-power vs full replacement against current $/W pricing.