The new procedure for identifying hot spots in photovoltaic panels

The thermographic inspection of photovoltaic fields is essential to analyze the correct functioning of the panels for the identification of hot spots, anomalies, which compromise the efficiency of the entire photovoltaic field. When a large PV field is to be inspected the Drone equipped with a thermal imaging camera can be used. In this way, in a timely manner, hot spots are identified which can also cause the fire in the cell, compromising the operation of the panel and generating criticality to the entire PV plant. The new functionality of Analist CLOUD 2019 is born from the necessity of the user to inspect and identify in a photovoltaic field, the panels that present anomalies or malfunctions, the hot spots, to program and proceed quickly with maintenance or replacement. Analist INFRAPRO provides a report that documents the anomalies identified in the PV field.

See INFRAPRO in action:

Workflow with Analist InfraPro

The thermographic data acquired with the flight of the drone equipped with a thermal imaging camera, are processed with Pix4Dmapper which generates the Reflectance Map containing all the thermal information of the area inspected. In this map the hottest areas (hot spots) characterized by a color that tends to white will be clearly visible, while the colder areas will appear much darker. Analist INFRAPRO imports the reflectance map and produces a detailed report showing the list of all the criticalities detected, identifying its position in the photovoltaic field.

Operating instructions

Loading the reflectance map

The Reflectance Map looks like an image with a tif extension. It is an orthophoto generated by Pix4D downstream of the elaboration of the photos of the thermographic survey.

To Load the Reflectance Map in InfraPro, from the Analist Project Palette, explode the “InfraPro Tools” node and double click on “Load IR Reflectance”, select the tif file you want to import and click OK.


Identification of Hot Spots

After loading the tif image, we can begin to detect the temperatures where anomalies are detected (Hot Spot) in the photovoltaic field.

To do this, in the “InfraPro” menu double click on “Infra-Tools”.


Detailed analysis of the plant

Click on the “Measure” button and the editor will be activated, asking as a first action to select the point whose temperature you want to know.

Once the point has been selected, the information must be entered to identify the anomaly and identify the area and then select the row and column.

Sampling and average temperature of an area

Click on the “Sample Hotspot” button and a window will open. which asks as a first action to sample the point of which we want to know the temperature.

Click on the “Sample” button to sample the point where you want to know the temperature.

Once the point has been selected, the information must be entered to identify the anomaly and identify the area and then select the row and column.

Finally the Position, or in which row of panels the anomaly is present.

Identified where the anomaly is located, the detected temperature is printed on the image and all the information summarized in the window, these can be completed with the identification code of the photovoltaic field, the flight code and the date.

It is also possible to detect the average temperature and the anomaly level of the panel by classifying the temperature. Click on the “Classify” button and draw a rectangle that marks the panel.

The system will calculate the average temperature in the panel, the delta between average temperature and anomaly temperature and the anomaly level.

With the “OK” button you proceed to save the hot spot that will later be reported in the Report.


Report production

After identifying all the Hot Spots in the field we can proceed to create the report. In the Infra-Tools dialog box double click on “Hotspot Report”.

It is possible to modify the report in the dedicated dialog box or export the csv extension report and edit it later.


Displaying the Infrared Histogram

In the Infra-Tools dialog box double click on “IR Istogram” and select a point of interest in the orthophoto.

A further window will open with the histogram of interest described by the Temperature-Frequency axes.


Identify and map the areas of the plant

Using the Polyline tool, select the area to identify and mark. After zoising the system, in the InfraPro palette, double click on Create Zone.

With the mouse cursor select the polyline and a dialog box will open where you can write the name of the area.


Thermographic inspection at your smartphone

Always carry with your thermographic inspections. In the InfraPro palette on the left, double click on Instanteat.

A dialog box will open in which you select, on the left, the instanteat of interest under the heading My Instanteat.

Now move the cursor over the “+” button, next to Elements. You must specify the name of the item and click OK.

Once published, the status will be shown in the lower part of the current window and the entry Published with success.