How Durable Are Solar Panels?

From hail storms to flooding, extreme weather events are becoming increasingly common across the globe. Therefore, solar companies must take certain precautions to protect PV equipment and ensure solar panel durability in extreme weather.

“We have a choice to build solar systems that can provide reliable electricity even when we have extreme weather damaging the grid,” said Dirk Jordan, senior reliability engineer for the National Renewable Energy Laboratory (NREL). “Certifications, including education and utilizing the best practices for regional extreme weather, will pay for themselves with cost-saving electricity.”

Solar panel durability encompasses weather resistance, mechanical strength, equipment longevity, reliability, resistance to degradation, equipment warranties, and certifications. Let’s examine this critical topic, so you can better serve your solar energy customers.

There are many types of PV modules used for residential and commercial solar power projects.

Monocrystalline solar panels are made from a single crystal structure, usually silicon, and have a black appearance. They tend to be efficient modules, but can be more expensive. Monocrystalline panels are typically known for their higher efficiency and longer lifespan compared to polycrystalline panels. This higher durability is attributed to the structural uniformity of monocrystalline silicon, which results in better resistance to stress and degradation over time.

Polycrystalline solar panels are made from multiple silicon crystals and have a speckled blue appearance. They are generally less efficient and durable than monocrystalline panels, but are often more cost-effective.

Thin-film solar panels use a different manufacturing process that involves depositing layers of semiconductor material onto a substrate such as glass or metal. They can be flexible and lightweight, and can be transparent or semi-transparent. Thin-film panels typically are less efficient than crystalline panels but perform better in low light conditions and at high temperatures. Although thin film panels have their advantages, they generally have shorter lifespans and lower solar panel durability compared to monocrystalline modules.

Building-Integrated photovoltaics (BIPV) are designed to seamlessly integrate into building materials, such as solar roof tiles or transparent solar windows. They serve both for generating renewable energy and as a structural component of the building. The durability of BIPV varies widely based on the material and application.

PV modules are designed to withstand extreme weather events, such as hailstorms, wind, and snow loads. Numerous elements help protect the lifespan of solar cells from moisture, UV radiation, wind-blown debris, structural damage, and other weather-related hazards that can reduce their lifespan.

Solar panels commonly consist of the following:

• Photovoltaic cells are made of a semiconductor material that converts sunlight into solar electricity.

• Encapsulation protects the delicate photovoltaic cells from environmental factors and prevents moisture from entering the panel.

• The backsheet layer provides electrical insulation and protection from moisture, humidity, and UV radiation.

• The frame often consists of aluminum or steel and provides structural support. It protects the components from mechanical stress and helps securely mount the panels to a racking system.

• The glass cover is made of a tempered glass cover on the front side of the panel to protect it from weather conditions and debris.

Many of these materials and design features increase solar panel durability and their ability to withstand extreme weather events. The encapsulation, backsheet, and glass cover protect the internal components from moisture, humidity, and UV radiation, which can cause damage over time. The frame provides structural integrity, while the tempered glass cover sheet offers resistance to impacts from hailstones, wind-blown debris, and other weather-related hazards.

As the temperature increases, the efficiency of solar panels tends to decrease, resulting in a decreased solar energy output. The decrease in efficiency with rising temperature is primarily due to the behavior of the semiconductor materials in the photovoltaic cells, potentially having both an impact on short-term electricity production and long-term solar panel durability.

The temperature coefficient is used to quantify this relationship and usually uses 77° F or 25° C as a reference temperature. It represents the percentage decrease in the power output of a solar panel for every degree Celsius increase in temperature above 25° C.

The temperature coefficient typically ranges from -0.2% to -0.5% per degree C but varies by the solar panel type and module quality. Thin-film solar usually has a lower temperature coefficient than monocrystalline and polycrystalline solar panels, so it performs well in hot weather. Likewise, monocrystalline solar panels generally perform better in hot weather compared to polycrystalline panels.

Prolonged exposure to high temperatures can have a degrading effect on the materials used in solar panels, potentially reducing their overall lifespan. Elevated temperatures can lead to thermal stress, causing the expansion and contraction of different components within the panel, which can weaken soldered connections and other delicate parts. Over time, this thermal cycling can contribute to the degradation of the solar cells and other materials, ultimately impacting the long-term performance and durability of solar panels.

Solar panels are designed to withstand a wide range of weather conditions and can generally perform well in extreme environments. However, certain factors, such as soiling, heavy rain, snow, hurricanes, and other severe weather conditions, can affect solar electricity output. Appropriate design, installation, and maintenance practices can help mitigate these effects. Refer to the PVEL PV Module Reliability Scorecard for information on how specific models perform.

The accumulation of dust, dirt, or other particles on the surface of solar panels can reduce the amount of sunlight reaching the solar cells. Soiling can be more pronounced in dry, dusty climates or near industrial sites. In fact, soiled solar modules are more likely to develop hot spots, which are a common PV panel defect that can impact long-term solar panel durability.

To address the issue of soiled solar panels impacting durability, regular cleaning and maintenance are essential. Implementing a scheduled cleaning routine can effectively remove accumulated dirt and debris from the surface of the panels, allowing them to operate at their maximum efficiency. Utilizing proper cleaning techniques and equipment, such as soft brushes and non-abrasive cleaning solutions, can help prevent damage to the panels while effectively removing soiling. However, it is critical to clean solar panels safely and avoid scratching the surface when promoting the durability of solar panels.

Although rain clouds reduce solar energy generation by obscuring sunlight, rainfall can also positively affect solar panel performance. Rainwater helps wash away dust and dirt, improving solar panel efficiency. Solar inverters can be sensitive to lightning, so use a surge protector and shelter them when possible to ensure solar system durability.

Snow accumulation on solar panels poses a challenge as it covers the surface and reduces the amount of sunlight reaching the cells. In regions with heavy snowfall, solar panels are often installed at an angle to encourage snow to slide off. Additionally, PV modules are designed to be durable and withstand the weight of snow loads according to local building codes and standards.

In some cases, periodic snow removal may be necessary to restore optimal performance. However, be careful not to scratch the modules as it can impact solar panel durability. Use a soft brush or a snow removal tool specifically designed for solar panels to safely remove the snow. Also, proper safety precautions are critical when on the roof, especially if the surface is icy.

Solar panels are designed to withstand high wind speeds and are typically tested according to international standards such as the International Electrotechnical Commission (IEC) 61215. This standard evaluates the mechanical strength of PV panels by subjecting them to simulated wind conditions. Panels that meet these standards are designed to resist damage from hurricanes and other severe wind events.

Solar permits in windy climates may have requirements for IEC 61215. These solar permitting requirements are designed to ensure the durability and performance of solar panels in various environmental conditions, including windy climates. However, specific permit requirements can vary depending on local regulations and the severity of the wind conditions in a particular area.

GreenLancer specializes in helping solar installers meet permitting and engineering requirements. The GreenLancer network is experienced in designing solar systems that comply with local regulations and standards for wind resilience, ensuring that your installations are safe and meet all necessary solar permitting criteria.

Proper conduit routing and electrical installation are critical to ensure the safety and performance of solar panel systems in areas prone to flooding. Electrical components and connections can be designed to be waterproof or housed in weatherproof enclosures. Conduit routing is carefully planned to avoid flood-prone areas, and if necessary, additional measures such as elevated mounting or flood barriers may be implemented. It is important to adhere to local building codes and regulations specific to solar panel installations in flood-prone areas to ensure longevity and safe operations.

After a weather event, it is crucial for solar installers to thoroughly inspect solar energy systems for any potential damage and issues with solar panel durability. Here are the important steps:

• Ensure personal safety: Before beginning any inspection, look for downed power lines or other hazardous conditions. Notify the relevant authorities and follow appropriate safety protocols as needed.

• Visual solar panel inspection: Visually inspect the PV modules for any obvious signs of damage, such as cracks, shattered glass, or loose connections. Check if any debris, like fallen branches, has made contact with the panels. Additionally, inspect the panel’s frame for any signs of bending or deformation.

• Solar system shutdown: If there are any visible signs of damage, shut down the entire solar array to prevent any electrical hazards.

• Grounding and wiring: Inspect the grounding system and wiring connections for any loose, corroded, or damaged connections.

• Solar mounting and racking: Check the mounting system and solar panel racking for signs of movement, damage, or misalignment. Look for loose or missing bolts, brackets, or other components, and verify the panels are still securely attached to the roof or the mounting structure.

• Electrical testing: If the visual inspection reveals no apparent damage, it may still be necessary to perform electrical testing. Measure the voltage and current output of the panels to ensure they are within the expected range. Any significant deviations may indicate hidden damage.

These are some of the top questions that solar customers may ask about solar panels in extreme weather conditions.

Solar panel warranties typically cover manufacturing defects and performance guarantees, not weather damage, because they fall under external factors beyond the manufacturer’s control. However, warranty terms can vary between manufacturers, so it’s essential to review the specific warranty from the solar panel manufacturer for accurate information. Homeowners’ insurance policies often offer coverage for weather-related damage to solar panels as part of their property protection coverage. Advise solar customers to check with their insurance providers to determine the extent of coverage for solar panels under their policies.

The best solar panels for hot climates typically have low-temperature coefficients to maintain efficiency. Monocrystalline panels have a single-crystal structure that allows for better heat tolerance and overall performance in hot climates compared to the multi-crystal structure of polycrystalline panels. Also, thin-film panels and bifacial panels are also suitable for high-temperature conditions. Choose panels with low temperature coefficients for optimal performance in hot climates.

Solar modules are designed to be weather resistant and are built to withstand various weather conditions including rain, snow, hail, and high winds. Solar panel manufacturers use materials such as tempered glass and durable frames to protect the solar cells from damage. However proper installation is critical for ensuring their resilience to weather elements, making them suitable for use in different climates and environments.

Yes, your customers can perform several tasks to help prevent weather damage. Depending on the roof and the homeowner, they may need to hire a professional to safely conduct some of these activities.

• Visually inspect solar panels, the racking system, and any associated wiring for signs of physical damage, such as cracks, chips, loose connections, or exposed wires.

• Remove any debris, such as leaves, branches, or dirt, from the surface of your solar panels. Accumulated debris can reduce the efficiency of the panels and eventually cause damage if left unattended.

• Trim trees near solar panels because falling branches or excessive shade from trees can affect solar system performance and potentially cause damage during severe weather events.

• Inspect the roof and mounting system for signs of damage, such as loose or corroded shingles, deteriorating flashing, or loose mounts, if homeowners can do this safely. Address any issues promptly to prevent roof leaks or structural damage.

• Monitor system output using a solar monitoring system and check inverter readings for unexplained drops in solar output. Ensure your customers have the required login information to monitor their production data.
  

Solar systems should be designed to withstand wind speeds typical for their installation locations. Standard solar panels can typically endure wind speeds of 90 to 120 miles per hour (145 to 193 kilometers per hour). However, specific solar panel wind ratings may vary by manufacturer and installation guidelines. Also, proper installation and solar panel mounting play crucial roles in ensuring modules remain secure in windy conditions.

Solar panels are generally durable and designed for long-term use. The glass covering provides protection against environmental elements, and encapsulation materials shield the sensitive photovoltaic cells. The backsheet acts as an additional protective layer. Properly manufactured solar panels can withstand harsh weather conditions, temperature fluctuations, and UV exposure.

Solar panels commonly last for about 25 to 30 or more years. However, most solar panels still produce electricity at the end of 30 years, but at a lower rate due to age-related degradation. Some solar panel models degrade more quickly than others, so refer to the power performance guarantee for information on the degradation rate.

Not only are solar modules designed to stand up to extreme weather, but solar battery storage can even mitigate the impacts of power outages from such events. For example, tens of thousands of PV systems with solar batteries were installed in Puerto Rico after Hurricane Maria. There are best practices that solar installers and homeowners should follow to prevent damage to solar systems from extreme weather.

Proper solar system design promotes durability in extreme weather through features such as sturdy mounting systems, weather-resistant materials, reinforced structures, and advanced monitoring systems that can detect and mitigate potential issues. These design elements ensure that solar systems can withstand harsh conditions and maintain optimal performance over time.

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