Solar Performance Diagnostics

Solar Diagnostics

While generally reliable, sometimes solar panels develop performance problems. All of our systems are backed by more than 10 years of ownership experience, and we stand behind every installation. We’re committed to ensuring solar PV systems perform at their best. 

VCT Group continues to expand our monitoring and solar diagnostics tools to help us get systems performing at their absolute best. In addition to our active monitoring program, we use a suite of solar diagnostic tools to help us identify underperforming elements in solar arrays.

Remote monitoring can help to diagnose issues, but sometimes further diagnostics and testing is required in the field.

Here’s a few of the diagnostic tools we use to enhance solar PV performance:

I-V Curve Tracing

I-V Curve Tracing is a fast, reliable, and comprehensive way to efficiently identify and diagnose performance issues in PV systems.

For each string in a photovoltaic array, an I-V Curve Tracer measures current and power as a function of voltage. Comparing voltage measurements of a range of electrical loads connected to a string are compared to expected results. By analyzing the shape of the curve, this can identify problem-causing elements in the string, such as which module, connector, or length of wire could be causing performance issues.

When a system seems to be underperforming, I-V Curve Tracing is an efficient method of troubleshooting and narrowing down potential issues.


Infrared Analysis

The cells within typical solar panels have an efficiency of approximately 20%. Simplified, this means that 20% of the light energy that hits the cell is converted to electricity, while the other 80% remains as heat. When a cell in a solar PV panel is malfunctioning or failing to properly convert sun energy to electricity, it gets hotter than other cells in a panel. Infrared analysis is able to detect these temperature variations, and point to where problems may exist within the panel. The same analysis can be done to cables and other electrical elements within the system, identifying heat build up and indicating where there may be performance problems.

When the conditions are right, infrared analysis can be performed on a system while it is in operation, without unplugging any components or shutting the system down.


Electroluminescent Testing

The cells inside solar panels are brittle, and can fracture or be broken from impacts or from mishandling. These fractures can be difficult to identify without special equipment. Electroluminescent testing works by running the solar panel in reverse; when applying current to a solar panel, normal functioning cells will emit very small amounts of light outside the visible spectrum. Where circuits and cells are broken, no light is emitted, as can be seen in the cracks in the accompanying image. Electroluminescent testing is an alternative to infrared analysis, but provides much more detail as to what problems may exist within a panel, and doesn’t require the panel to be in operation under ideal conditions.

Fascinating photo of the light emitted from a cracked solar panel that has been run in reverse by running electricity through it.