Non-destructive thermal control and thermal imager inspection of solar power plants.

Sometimes it happens that a new solar station does not enter the specified operating mode. Or, a station that has served for many years is significantly losing power.

It is not about bad weather or a few percent drop in power. We are talking about productivity losses of tens of percent. Such declining performance, if not taken decisively, threatens us to increase the payback period of the stations for years.

So what can happen if the basic elements are at first glance in order?

Because of the law of building an electrical system, the performance of series-connected photomodules falls in proportion to reducing the number of properly functioning cells. And the current will be equal to the current of the weakest link. That is why partial shading of the solar station should be avoided in every way. After all, when shading a small part of one module significantly affects the performance of the entire system.

If on a sunny day the station does not produce the required amount of energy then this may be due to the failure of several cells in different photomodules. And in 99% of cases it is not visible to the naked eye. Damage to a fragile cell without visible damage to the cover of the photomodule is quite easy. This can happen during careless installation and during transportation or it can be dirty.

How to find faulty photomodules?

Option 1:

Disassemble the system and gradually measure the characteristics of each panel. The cost of this option is quite significant, and efficiency is questionable. You can start checking the station at one light level and finish at another.

This option has only one conditional plus - it does not require expensive equipment.

Option 2:

The least time consuming and the most effective. You can evaluate the correctness of the photomodule on its thermal properties remotely. After all, in case of damage (contamination), the cell of the photomodule begins to work in a completely different thermal mode and it is clearly visible in the thermal imager.

The advantages of this method of verification are:

•         The station can be checked during its operation

•         Photo modules do not require disassembly

•         Can be held in large areas

Cons are also:

Not every thermal imaging camera is suitable for this test.

The sensitivity of the thermal module of the thermal imager should be ≤0.08K. 320 * 240 pixels resolution preferred. We will not talk about the value of such devices better. To buy such a device for checking your home solar station is absolutely inappropriate. But you can order a thermal imaging or rent a thermal imager.

The following rules must be followed for successful verification:

1) Have a suitable thermal imager with a sensitive sensor, because the protective glass of solar modules may be opaque to low-cost thermal imagers.

2) Manual level and temperature range adjustments are desirable

3) Checking should be performed at an insolation level of at least 500 W / m2 (preferably in winter, then we will get the most contrasting image). Although having a wide-range thermal imager, you can test in the summer.

4) Choose the correct angle of placement to the plane of the photomodule. 5-60 °

If there is a possibility of visual access to the back of the photomodule, it is better to diagnose from the back. In this case, we get rid of stray reflections on the glass and improve the accuracy of diagnosis.

Photomodules should be under load

What faults can be diagnosed in this way?

In thermal imaging diagnostics of a photoelectric station we can see the following:

        If the entire panel is hotter than the neighboring panel, this indicates a connection problem.

        If individual elements (or dots on the elements) are full of hot spots, this indicates defective diodes or internal short circuits.

        An image of the type "flap blanket" indicates a problematic diode in the module.

    Higher power cells have a high temperature, which indicates connection problems

Solar Power Thermal Audit Hot points on individual cells speak of physical defects.

This hot spot in one place indicates a physical defect in one of the solar cells.

Resume.

Thermal imaging diagnostics of photoelectric systems is the most rational method. Allows you to check both individual fields and specific photomodules without shutting down the system, which saves resources and time.

If you are having trouble finding the cause of your solar power unit's drop in power, then contact us for thermal imaging of the photomodule field.

  Thermal imaging inspection of solar thermal power plant imager and non-destructive thermal control price here

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