Micro-Cracks in Flexible PV Modules: Causes, Impact, and Prevention

As photovoltaic (PV) technology advances, thinner and more flexible solar panels are becoming common, particularly for specialized applications like boats and marine environments. However, this push for lightweight and cost-efficient modules comes with a downside: increased susceptibility to micro-cracks. These tiny fractures can significantly impact the efficiency and longevity of PV systems, especially in challenging conditions like those encountered at sea.

Micro-cracks are a significant concern for manufacturers and end-users alike. Many manufacturers are not taking solar panel durability seriously due to the invisibility of the damage, and the early adopter mentality. At Open Waters Solar, our automated manufacturing process ensures precision and eliminates microcracks during production, while our advanced encapsulation method protects against microcracks developing in real-world conditions. To learn more about why we focus on creating ultra-durable solar panels, visit our About Us page.

Understanding Micro-Cracks

Micro-cracks are microscopic fractures in solar cells caused by mechanical stress, temperature fluctuations, or poor handling. They are often invisible to the naked eye but can obstruct current flow, reducing the panel's power output. Flexible PV modules, which are increasingly used in marine and sailing applications, are particularly prone to micro-cracks due to their fragility.

Studies have shown that at least 6% of solar panels develop micro-cracks before they even reach the customer, and these cracks often worsen during installation or operation. For flexible modules used on boats, excessive bending and constant vibration from waves and engine movement can exacerbate this issue. For more details about how solar cracks happen, check out our article on Solar Cracks.

Types of Micro-Cracks

Micro-cracks can be categorized by their orientation and the damage they cause:

• Parallel Cracks: These run along the busbars, the main electrical conductors, and are the most damaging type. Studies show that 50% of failed cells have cracks parallel to the busbars.
• Perpendicular Cracks: These run across the busbars but have minimal impact unless soldering is poor.
• Mesh Cracks: These form a web-like pattern, dividing the cell into fragments. Such cracks can cause hot spots and significantly reduce performance. Learn more about how shade also creates hotspots in marine solar panels in our post about Shading and Marine Solar.
• Dendritic Cracks: Similar to mesh cracks, these do not fully divide the cell but can spread over time, leading to severe degradation.

Impact of Micro-Cracks on Performance

Micro-cracks disrupt the flow of electricity within the solar cell, leading to power loss and other issues:

• Power Loss: Cracks parallel to busbars are the most harmful, while cracks at a 45° angle cause only 25% of the power loss as seen with parallel cracks. Some flexible solar panels have been known to decrease 50%+ after the first year due to microcracking from regular usage. 
• Hot Spots: Fragmented cells can overheat, further damaging the module and potentially creating safety hazards. 

For marine applications, where solar panels are exposed to constant motion, temperature fluctuations, and salty air, these issues can lead to rapid degradation if not addressed. Explore our products to see how our solutions address these challenges.

Causes of Micro-Cracks

Micro-cracks can occur during various stages of a PV module’s life cycle:

• Manufacturing: External forces during soldering, lamination, or framing can create stress points.
• Transportation: Vibration and improper handling during shipping can cause damage, especially to flexible modules.
• Installation: Bending modules to fit curved surfaces, such as the deck or hull of a boat, increases the risk of cracks.
• Environmental Stress: Temperature fluctuations and humidity changes exacerbate existing cracks.
  
  

Detection Methods

Detecting micro-cracks early can prevent larger issues down the line. One of the most effective methods is Electroluminescence (EL) testing, which uses near-infrared imaging to identify hidden defects. This technique is highly sensitive and widely used in quality assurance processes.

Why Micro-Cracks Matter in Marine Applications

On boats and yachts, solar panels are often used to power critical systems, from navigation to refrigeration. Any reduction in efficiency caused by micro-cracks can compromise energy autonomy, particularly during long voyages. Furthermore, the constant motion and harsh conditions at sea make flexible PV modules more susceptible to damage, emphasizing the need for robust designs and preventive measures. Read more about how solar panels can power vital equipment on boats in our blog on Solar for Sailboats.


Explore the Strongest, Lightest, and Most Durable Marine Solar Panels on the Market