In many EPC contracts for photovoltaic plants, there is a requirement to perform thermographic inspections using drones only when the irradiance is at least 600 W/m², even during winter. Although this practice is common, its technical basis is not always justified. Here’s why:
Technical Reality
There is no thermal defect in a photovoltaic module that can be detected at 600 W/m² but not at 450 W/m², as long as:
- The parameters of the thermal camera (emissivity, reflected temperature, measurement distance, etc.) are correctly configured.
- The inspection is carried out by qualified professionals using high-quality equipment.
The Importance of Equipment
Not all thermal cameras are the same. Low-quality cameras, such as those integrated into well-known brand drones designed for general use, do not allow the configuration of essential parameters for performing accurate inspections under lower irradiance conditions. However, by using professional cameras designed for industrial applications, it is entirely feasible to obtain reliable results at lower irradiances.
Impact on Projects
Requiring a minimum of 600 W/m² during winter can delay inspections due to the limited availability of days with sufficient irradiance. This can:
- Increase execution costs.
- Delay the commissioning of the plant.
- Generate unnecessary conflicts regarding the interpretation of contractual requirements.
Our Recommendation
Include in EPC contracts the obligation for thermography to be performed with professional equipment by trained personnel, ensuring proper parameter configuration. This will guarantee reliable results, even at lower irradiances, and optimize the process without compromising quality or safety.
450 W/m² in winter is more than sufficient, and no, the IEC62446-3 standard does not require 600 W/m²; it only recommends it. What the standard states is that the conditions for the precise detection of thermal anomalies must be met.
I challenge anyone to show me a defect in a photovoltaic module that is visible at 600 W/m² and not at 450 W/m² with a good camera operated by an experienced professional. At Gudnus, we have several clients on both sides of the Atlantic who cannot carry out commissioning tests until March or April due to a “copy-paste” of this inflexible requirement. From a technical perspective, it makes no sense.