How to Check the Quality of Solar Panels in 3 Simple Steps

When choosing solar panels, quality is key for system performance and durability. With many options available, selecting high-quality panels can be challenging. This article outlines practical methods for assessing panel quality—appearance checks, label verification, and electrical measurements—to help you make informed decisions. These steps will enhance your purchase choices and ensure efficient, reliable photovoltaic system performance.

Inspecting Appearance

Check the Color: Efficient monocrystalline silicon solar cells are typically a uniform black, while polycrystalline silicon cells are usually a consistent light blue or sky blue. If the panel’s color is dull or inconsistent, it likely indicates poor craftsmanship.

Examine the Surface: The tempered glass surface of the panel should be smooth and free from foreign objects. Some manufacturers may neglect to clean silicone droplets from the glass surface, which can impact energy generation efficiency.

Inspect the Cells: Solar panels should consist of intact cells cut from a single piece. Many unregulated manufacturers use broken cells pieced together, which can result in disconnections over time. Look for any signs of cutting marks to identify such issues. Although these problems are hard to detect with the naked eye, they pose significant risks as the panel ages.

Check the Back: Examine the back of the panel for any irregularities after applying pressure, such as bubbles or wrinkles.

Inspect the Frame: Due to the low entry barrier in the solar panel industry, many small manufacturers use manual framing, which can result in uneven framing and poor fitting. Modern panels usually feature aluminum alloy frames for better durability.

Examine the Silicone: Ensure the silicone around the edges of the back panel is evenly distributed and securely fills the gaps between the back panel and the frame.

Check the Soldering: Inspect the soldering of the cells for any signs of poor workmanship, such as incomplete soldering. Also, check if the cell arrangement is orderly.

Inspect the Junction Box: Finally, verify that the junction box is securely attached and that its cover fits tightly. Check if the wire connectors rotate smoothly and can be tightened effectively.

Compare Prices: If distinguishing the quality through the above methods is challenging, comparing prices can be a useful approach. Although international solar panel prices fluctuate, there is a general range. If a manufacturer offers a price significantly below market value, it warrants further scrutiny.

In conclusion, there are many aspects to consider when evaluating the quality of solar panels. The points mentioned above are useful for non-professionals to assess panel quality without specialized equipment. However, some quality issues may not be visible to the naked eye or may become apparent only after some time. To safeguard your interests, it is advisable to have panels tested by professional institutions.

Checking Labels

When purchasing photovoltaic panels, checking the labels on the panels is crucial. These labels help you quickly identify the panel’s brand, model, and certifications, which aids in selection and comparison.

• Brand Identification (Manufacturer or brand name of the solar panel)
• Model Identification (Solar panel model or specifications)
• Certification Marks (Standards the solar panel has passed, such as TUV, IEC, CE, etc.) 

If the solar panels lack these markings, special attention should be paid to their quality and performance. Some solar panel brands may place labels on the front or back of the panel, showing important parameters like voltage, current, power, etc. If these parameters are available, they can be measured to verify if they meet the performance requirements of the panel.

Measuring Parameters

To assess the performance of a solar panel, you can measure several electrical parameters. When selecting photovoltaic panels, measuring the open-circuit voltage (Voc), short-circuit current (Isc), maximum power point voltage (Vmp), and maximum power point current (Imp) can help evaluate their performance. Here are the steps to perform these measurements:

1. Prepare Tools: You will need a multimeter, safety gloves, and a solar panel.
2. Measure Open-Circuit Voltage (Voc):Set the multimeter to DC voltage mode, connect the positive and negative leads to the corresponding terminals on the solar panel, and read the displayed value.
3. Measure Short-Circuit Current (Isc): Set the multimeter to DC current mode, connect the positive and negative leads to the corresponding terminals on the solar panel, and read the displayed value.
4. Measure Maximum Power Point Voltage (Vmp) and Current (Imp): Connect a variable resistor (load) to the panel, adjust the resistor until the reading on the multimeter reaches its maximum, and record the voltage as Vmp and the current as Imp.

When measuring parameters, follow safety guidelines, such as wearing safety gloves to prevent electrical shock. If the measurement results align with the manufacturer’s specifications, it indicates stable performance and good quality of the photovoltaic panel.