SOLAR THERMOGRAPHY

Thermal Imaging of solar panel

OVERVIEW

This is a thermogram of a single hot defective cell in a PV solar panel. Infrared inspection of photovoltaic solar panels is a 100% coverage, non-destructive diagnostic tool for finding bad photovoltaic cells, which reduce the power output PV panels. We can scan a single panel or large array. Infrared thermal imaging of PV panels can locate defective wiring connections and malfunctioning inverter boxes.

A single bad cell can get hot enough to melt the solder connections, reduce the power output, crack the panel’s cover allowing moisture to enter the panel, and cause the entire panel to fail.

The thermographic infrared inspection is conducted with the solar panels in operation, from the front side for roof-mounted panels or from the backside on elevated arrays. No down time is required for conducting the inspection and there is no interference with the production of power during the inspection.

Infrared inspection of PV solar panels should be part of the quality acceptance procedures of any new installation and for the ongoing maintenance of established arrays.

DETAIL

Infrared inspection of solar PV Panels quickly finds bad cells within a single panel or an entire array. Thermal imaging can also locate malfunctioning inverters and hot electrical connections. Defective PV cells reduce panel efficiency and can lead to a premature failure of the panel. Infrared inspection of photovoltaic solar panels is a 100% coverage, non-destructive inspection tool for finding bad cells in PV solar panels.

The inspection is conducted with the panels in operation, from the front side for roof-mounted panels or from the backside on elevated arrays. No down time is required for conducting the inspection and there is no interference with the production of power.

The electrical current flowing through the cells in a panel flows from positive to negative, cell to cell. When there is a defective cell somewhere in the string of cells, it can limit the current flow produced by the good cells. If there is enough voltage produced by the good cells, they can force the defective cell to operate in a “reverse bias” mode which forces it to carry the current in a reverse direction to its semiconductor design. When this happens, the power produced by the good cells is dissipated across the defective cell, turning electrical power into HEAT. Because the power is converted into heat within in the bad cell, it is not delivered to the panel’s output to do work, reducing the panel’s power output and efficiency.

A single PV cell in a panel is not designed to dissipate large amounts of amount of excess heat. Without the ability to conduct, convect or radiate the excess heat out of the cell, it gets very hot. This localized cell heating creates “hot-spots” which are visible to infrared and can get hot enough to cause secondary defects in the panel. The localized cell heating overheating creates “hot-spots” on the panel which are visible to infrared, and they can get hot enough to cause secondary defects in the panel.

Panel problems such as melted solder connections, cracking of the protective glass cover which allows moisture into the panel and the degradation of adjacent cells in the panel, can be caused by these overheated cells.

Infrared inspection of PV solar panels should be part of the quality acceptance procedures of any new installation and for the ongoing maintenance of established arrays.

Share this Page: