Solar panel inspection by drone relies on thermography: an on-board infrared camera spots modules whose temperature differs from the rest of the installation — the “hot spots” — without touching the panels or climbing onto the roof. In a single flight, the drone reviews hundreds of modules, where a check on foot would take far longer.
What does thermography detect on a photovoltaic installation?
A faulty module heats up more than its neighbours; the thermal camera makes that difference visible. Typical cases:
| Anomaly | Thermal signature | Comment |
|---|---|---|
| Short-circuited bypass diode | Clear hot spot on part of the module | Detectable even at low sunshine according to recent studies |
| Heavy soiling | Locally hotter area | Often fixed by a simple clean |
| Broken interconnection | Hotter cell or string | Detectable at high sunshine |
| Cell crack | Faint signature | Hard to distinguish by thermography alone |
Thermography complements the installation’s electrical measurements; it does not replace them.
In what conditions should the drone fly?
Standard IEC TS 62446-3, the reference for thermography of photovoltaic installations, and current practice recommend:
- strong sunshine: irradiance of at least 600 W/m² in the plane of the modules;
- light wind: under about 28 km/h;
- little cloud;
- clean modules, so that soiling is not mistaken for faults.
This is the opposite of building thermography, which is usually done early in the morning or at night (see our article on thermal drone inspection): here the installation must be producing for faults to show. Resolution matters too: recent studies aim for around 5 × 5 pixels per cell, which sets the flight altitude.
How a mission works
- Choosing the slot: a weather window with enough sunshine and light wind.
- Thermal flight: infrared images of the whole installation, complemented by visible-light photos.
- Analysis: locating hot spots and interpreting anomalies (Pro package).
- Delivery: thermal images, and a technical PDF report with diagnosis for the Pro package.
Thermal inspection prices
| Package | Price | Contents |
|---|---|---|
| Thermal Essential | CHF 500 | High-resolution thermal images, raw files, no diagnosis |
| Thermal Pro | CHF 1,000 | Diagnosis of anomalies, interpretation, full technical PDF report |
| Thermal Project | On quote | Large installations, 3D thermal modelling |
Why check your installation?
- spot a fault early, before it damages the module;
- document an anomaly, for example before a warranty expires;
- check an installation after commissioning.
Frequently asked questions
When should solar panels be inspected by thermography?
In daylight, with strong sunshine (standard IEC TS 62446-3 and current practice recommend irradiance of at least 600 W/m² in the plane of the modules), light wind (under about 28 km/h), little cloud and clean modules.
What does drone thermography detect on a solar installation?
Hot spots: short-circuited bypass diodes, heavy soiling and broken interconnections. Cell cracks, on the other hand, are hard to distinguish by thermography alone.
How much does a solar panel inspection by drone cost?
From CHF 500 with the Thermal Essential package (high-resolution thermal images, raw files, no diagnosis); CHF 1,000 with the Thermal Pro package (diagnosis, interpretation and technical PDF report). Large installations are quoted individually.
See also our thermal survey services, our guide to drone inspection prices or request a free quote: we reply within 24h anywhere in French-speaking Switzerland.