damage analysis at three pv plants lithuania

Investigation of damage patterns on bifacial PV modules

“Quality assurance is the cornerstone of our work. Every component and every detail of a photovoltaic system is carefully tested to ensure longevity and optimal performance. This is not a compromise, but a promise. Our customers can rely on us to test their photovoltaic systems with the utmost precision and care”.

The causes of glass breakage in PV modules are complex and can be influenced by various factors, including the design and materials of the modules, weather conditions and handling during transport and installation. Our many years of experience with PV modules have enabled us to identify the exact causes and advise the customer quickly.

Glass breakage in PV modules can be caused by various factors:

Mechanical stress:
PV modules are exposed to various mechanical loads such as storms, hail or snow. These can cause the glass to break or crack.

Temperature differences:
Temperature differences between day and night or between seasons can cause stresses in the glass that can lead to cracks or breaks.

Manufacturing defects:
Errors during the manufacturing process can lead to weak points in the glass that can later cause breakage.

Installation errors:
Incorrect installation of the PV module or improper handling can lead to glass breakage, e.g. due to impacts or unintentional dropping.

Deviation from bill of materials:
Deviations from the original BOM can also mean that the components no longer have the same properties.

When investigating damage patterns, it is therefore important to work with a partner with many years of experience who can accurately identify the causes.

There are also industry-specific standards such as IEC 61215 and IEC 61730, developed by the International Electrotechnical Commission (IEC), which specifically address the performance and safety requirements of PV modules. Although they are not ISO standards, they are often used in the PV industry as a benchmark for the quality of PV modules.

The certification of PV modules according to IEC 61215 and IEC 61730 promises higher quality, improved safety, performance guarantees and facilitates the integration and financing of PV systems. They ensure that your PV system complies with the applicable industry standards and operates reliably and efficiently.

One strategy to detect defects in a photovoltaic system at an early stage is to continuously monitor the performance ratio (PR). This is a characteristic value that provides information about the condition and performance of the system. The performance ratio is the quotient of the energy actually generated by the system and the theoretically expected energy generation based on the installed module output and the weather conditions.

A high performance ratio indicates that the PV system is working efficiently and is close to the expected performance. A low performance ratio, on the other hand, may indicate various problems that can affect the performance of the plant.

By regularly monitoring performance, potential problems can be detected at an early stage. If the Performance Ratio is low, it is advisable to carry out a detailed examination of the system to determine the cause and, if necessary, initiate appropriate measures to improve the performance or repair the system.

Glass breakage patterns like these were found on several PV modules.

a quick glance

Inspected PV plants


System size

> 100 kWp




Analysis of damage patterns on bifacial PV modules


November 2022