The Most Common Problems with Photovoltaic Panels
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The Most Common Problems of Photovoltaic Panels? 4 Answers (with Solutions)

The production of photovoltaic panels can be managed according to low or high quality benchmarks agreed by the producer. In the perspective of modern and efficient industrial production, it is important that the most common problems of photovoltaic modules are solved at the production stage, BEFORE the commercialization of the modules themselves. Operating in this way means ensuring that the production meets the expectations of the customers, avoiding costs for assistance, product withdrawal, and warranty. So, how can the most common problems of photovoltaic panels be solved? First of all, it is important to know what these problems are.

The issue of Cell Microfractures

Also known as "microcracks," the problem of microfractures can manifest itself during the initial, delicate phase of cell stringing. These cells undergo thermal soldering, which creates the series of cells in the photovoltaic module. If a microfracture occurs, the damaged cell will lower the module's yield, energy performance, and panel quality. Consequently, the accuracy and quality of soldering become essential prerequisites for managing high production volumes with a minimal microfracture rate. Specialized machinery, such as stringers and layup machines, have been used for some time now, with soldering capacities of up to several thousand cells per hour. Not all stringers are the same, as they do not all adopt the same soldering technique and do not all have the same degree of dynamism and flexibility. For those seeking excellent performance, at Ecoprogetti, we offer stringers with:
  • Tough tested infrared soldering to reduce thermal stress and achieve excellent soldering.
  • Integrated camera for high-precision alignment between busbars and ribbons.
  • Camera to detect and reject broken or chipped cells before soldering.
  • High level of dynamism allowing work with photovoltaic cells and ribbons of different sizes and types.
  • Low cost of spare parts and consumables.
  • Easy and intuitive to use.
  • Integrated remote support connection in the machine.
Result: Overcoming the delicate process of cell stringing and aligning them on the panel glass with high quality and efficiency.

The panel delamination issue

The subsequent phase in the production of photovoltaic panels involves laminating the layers that make up the module. The machine responsible for lamination is called a laminator, and the material used to transform the sandwich into a single block is encapsulants (i.e. EVA ethylene-vinyl acetate). Delamination occurs when the layers of the panel, due to non-compliant material or an inadequate process, begin to separate from each other, even if only partially. Delaminated panels lead to poor electrical insulation, oxidation of cells and connectors (ribbons), and ultimately a reduction in the voltage of the entire system. Repairing the rest is difficult and often not feasible, so the only alternative is often to replace the panels. At Ecoprogetti, we have been developing cutting-edge laminators for over 25 years, increasingly innovative and capable of ensuring constant, high-quality lamination. Specifically, our machines:
  • Fully electric laminators for greater temperature uniformity control, allowing temperature adjustment during the processing cycle.
  • Operate with plates at controllable temperatures with a uniformity of ±2°C.
  • Ensure uniform gel content testing across the module surface.
  • Excellent vacuum quality, final vacuum level <1 mbar in approx. 100 sec.
  • Minimum membrane durability of 3000 cycles.
  • Ability to work with various types of encapsulants, front sheets, and back sheets.
  • Allow membrane replacement in less than 30 minutes.
  • Can be integrated into an automated production line.
  • Electric laminators are safer and allow more precise temperature control in various areas of the module.
  • In conjunction with the laminator, Gel Content Kits and Peeling Test Kits are used.

Result: Almost zero risk of delamination!

Quoted from "Assessment of Photovoltaic Module Failures in the Field," Report IEA-pvps t13 09:2017.

The issue of hot spots on panel cells

Another common problem is that of hot spots. In technical terms, a hot spot is a point on the panel where heat accumulates to the extent that it damages the photovoltaic panel. Photovoltaic panels generate a significant amount of energy, and hot spots can occur when a portion of that energy is dissipated in a localized area. Typically, hot spots are not stable and tend to intensify until there is a complete collapse of electrical performance and panel safety. Regardless of the number of cells within a module, a single damaged cell can cause poor insulation and ribbon disconnection, leading to the risk of a fire in the area and permanently affecting the operation of the entire system. The factors that can cause hot spots are diverse but mainly fall into two categories: 1) Electrical issues in the cells (leading to shunt resistances). Cells damaged during the production process, as cells undergo various types of stress during lamination, transport, soldering, and installation. We recommend focusing on the quality control of cells with the help of the Ecosun Cell, the most precise LED photovoltaic simulator for photovoltaic cells available on the market. 2) Hot spots can be detected before lamination with specific tools. In cases where hot spots develop in the system, the only protection is through bypasses or optimization systems. Machinery that allows for the quality control of cells and photovoltaic modules includes photovoltaic simulators, electroluminescence testing machines, and hi-pot testers. The strengths of our machinery are as follows:
  • Developed after years of Research and Development, tested and appreciated by leading research laboratories and large production lines.
  • High quality and precision of the testing machines and software (all developed in-house).
  • Photovoltaic simulator with certified LED technology and winner of several awards (Ecoprogetti developed the first LED simulator on the market in 2010)
  • Continuous process monitoring and control.
  • Compatibility with crystalline and thin-film modules.
  • SQL database for data storage.
  • Automatic module loading and unloading system.
Result: Minimal risk of hot spots on panel cells!

The snail trail effect on photovoltaic modules

The last and perhaps the most insidious of the most common problems affecting photovoltaic panels is called the "snail trail effect." This optical effect, visible to the naked eye, occurs in conjunction with the micro-cracking of one or more photovoltaic cells. As soon as heat, photovoltaic radiation, and humidity interact with the panel, you can start to notice the typical snail-like trails on the damaged cell. Although it is very difficult to quantify the decline in yield of a panel affected by this problem beforehand, it is clear that the presence of the snail trail effect indicates damaged cells. Once again, the solution is to rely on testing machinery, specifically direct tests such as electroluminescence. These tests allow you to evaluate a new material and assess its performance under stress conditions. Don't hesitate to take action and request a personalized consultation with no obligation!

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