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Impact of Hail on Solar Panels: Briefly About the Main Factors

A residential roof with solar panels damaged by hail

Solar panels are gaining popularity as an environmentally friendly and cost-effective energy source, especially in cities like Chicago.

However, like any other technology, it has flaws, and hail can threaten its integrity.

According to MoneyGeek, hail damage in the USA crossed the billion-dollar mark in 2022. NREL demonstrated a clear trend: PV systems exposed to extreme weather events lose their performance over time. In particular, hail with a diameter of more than 25 mm reduces annual electricity generation.

In this article, we will try to answer the most popular questions about solar panels and hail damage:

   Can solar panels withstand hail?

   How does hail affect the performance of photovoltaic panels in Chicago?

   What factors determine the degree of damage?

   How to protect solar panels from hail?

Solar Panels vs. Hail: Factors That Impact the Damage

Can solar panels be damaged by hail? Yes, but high-quality solar panels do not break down in hail storms because they are built to work in harsh weather conditions. They can withstand bad weather for many years, ensuring uninterrupted energy production.

However, hail may damage solar panels. It is one of eight threats named “heavy rainfall.”

Solar panel system threats
 

Source: 8billiontrees
 

Small hail, as a rule, does not cause damage. However, heavy hail, especially if it falls over a long time, can:

   Break the glass or acrylic coating of the panels

➥   Damage to individual solar cells

Because of this, the panel’s performance decreases. Moreover, panels may become completely unusable and have to be replaced.

 

Let’s talk more specifically about what determines the level of solar panel damage from hail in Chicago.

Hail Size

The larger the hail, the more likely it is to cause serious damage to the PV modules.

  • Big hail (3 cm+) is more likely to cause serious damage to the panels
  • Small hail (up to 1 cm) usually does not cause damage
  • Moderate-sized hail may cause damage, the extent of which depends on other factors

In Chicago, the size of hail usually does not exceed 20 mm, making the risk of serious damage to PV panels low.

Angle of Impact

Falling hail on solar panels installed at the right angle will likely do more damage. Therefore, setting up the panels at an optimal angle increases the likelihood of deflecting hail and reducing damage.

In Chicago, solar panels are typically installed at an angle of 30–45 degrees, which minimizes hail damage on solar panels.

Hail Speed

The speed of hail significantly impacts its kinetic energy and, therefore, the degree of damage.

   Fast hail (over 70 km/h) causes significant damage

➥   Slow hail (up to 30 km/h) causes no damage

In Chicago, the speed of hail falling during a thunderstorm usually does not exceed 60 km/h. This is much lower than the threshold level, which, as a rule, causes serious hail damage to solar panels.

Panel Material and Construction

Not all solar panels are equally hail resistant because they are made of different materials. Panels made of tempered glass with a thick layer are the best hail-resistant solar panels, while acrylic ones are more prone to damage.

Additional factors that affect durability are frame type and build quality. Yes, choose modules with an aluminum alloy frame, which is essential in providing rigidity and protecting solar panels from hail.

Hail Duration

A long hailstorm causes more damage than a short one. Fortunately, hail typically lasts up to 15 minutes in Chicago. This is significantly less time than it takes to accumulate significant damage on the panels.

Visible Signs on Solar Panels Destroyed by Hail

If you recognize solar panel hail damage, you can repair or replace the equipment quickly.

Not all damage is obvious, so knowing what signs to look for is important. The main ones include:

 ➥   Cracks in the glass cover: This is the most common type of damage that causes corrosion due to the penetration and accumulation of moisture and dust in the panel.

 ➥   Dents in the glass cover: Deformation of the panel disrupts its optical properties and reduces the overall efficiency.

 ➥   Cracks on a glass cover: Even shallow scratches reduce the stress concentration inside, enabling new cracks to appear.

 ➥   Damage to the panel frame: Hail may damage not only the panel itself but also its frame, weakening its structure.

 ➥   Damage to solar cells: If you notice that your solar system produces less electricity than usual, its output power decreases due to the unstable operation of solar cells.

 ➥   Damage to wires: Yes, it is no joke; hail can damage the cables that connect the panels if they are not well protected. System interruptions will occur immediately.

The work of solar panels damaged by hail also varies depending on the degree. Cracks, dents, and scratches scatter sunlight, reducing the amount of light that reaches the photovoltaic cells. As a result, the panel’s performance drops.

A short circuit could occur due to water entering the panel through cracks, raising the fire risk.

In some cases, hail damage to solar panels can be so significant that they fail. It is probably the worst outcome for the owner.

Looking for more information about solar panels and hail damage or how to protect your solar system? Don’t waste another minute — get your free solar quote right away!

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Are the Owners of Solar Panels in Chicago in Danger Because of Hail?

PV owners in Chicago are concerned about the impact of hail on their investments. Installing a home or commercial solar system requires significant funding, effort, and careful selection of suppliers and installers. Therefore, it is natural that the question arises: Are solar panels resistant to hail?

Indeed, some US states, such as Colorado, Nebraska, and Texas, are more likely to experience severe hail, making them more vulnerable to PV module damage. These states are located in the so-called “hail alley,” where many large hailstones fall annually.

Map showing U.S. states with the highest expected hail damage losses per capita in 2022.

Source: MoneyGeek
 

However, residents can stay calm in Chicago, Illinois, because hail is rare. If it does happen, it is moderate anyway.

 

                                                                                                 Please note! FEMA offers a web interface with a map showing county-specific hail risk ratings. Scores are divided into four categories: very low, relatively low, relatively high, and very high.

 

FEMA's web interface displaying a map depicting county-specific hail risk ratings.
 

Source: FEMA

Most PV panels are designed to withstand hail up to 25 millimeters in diameter. However, unforeseen situations may occur. There is a small chance of severe hail in Chicago, possibly damaging even the strongest structures.

Therefore, solar panel owners in Chicago are still advised to:

   Choose panels that are resistant to hail and made of certified materials

   Use the services of qualified panel installers, as poor installation increases the risk

Material and Durability: How Are They Related?

Hail resistance is only one factor to consider when selecting photovoltaic panels. This is true because it is also important to consider efficiency, cost, and warranty. However, all this is leveled if a hailstorm crushes the solar system suddenly.

Different materials have different resistance to mechanical shocks or thermal expansion that may lead to panel damage.

 

So, considering the materials, let’s start with the least stable and gradually move to the best options.

  1. Silicon: Strong material, but can be brittle when struck. Silicon panels are the most common in Chicago.
  2. Thin film: Such panels are made of a thin layer of photovoltaic material — amorphous silicon or CdTe. They are usually more flexible than silicon and, therefore, more precipitation-resistant.
  3. Perovskite: A class of artificial crystals. Such panels have yet to enter the mass market but have the potential to be very durable due to their resistance to mechanical shocks.

Do your research and compare the different options available before purchasing.

Protecting Solar Panels From Hail: Effective Tips

Solar panel cracks caused by hail
 

Are you concerned that you will install solar panels and hail damage will cause random markings and holes? Fortunately, there are some tips you can follow to reduce the risk of damage.

Tip 1: Choose Hail Proof Solar Panels

When choosing panels, pay attention to thin-film or perovskite panels. They are more flexible and resistant than traditional silicon.

Also, some manufacturers offer hail-resistant solar panels. Look for models with the appropriate certifications, such as UL 790 or IEC 61215.

Tip 2: Check the Installation is Correct

Install the panels at an optimal angle so that the hail can slide off the surface while losing the force of the impact. In Chicago, such an angle is up to 40 degrees.

Test a panel fastening system for strength by contacting qualified specialists. We recommend you inspect the mounting system of photovoltaic modules annually and every time after severe weather events.

Tip 3: Think Over Protecting Solar Panels From Hail

One of the most efficient approaches to protecting solar panels from hail is installing special protective covers on the panels. These covers are made of a strong material (such as polycarbonate or aluminum) that can withstand the impact of hail and protect the glass surface.

Special protective films made of strong plastic or polyethylene can be temporarily applied to the panels during seasons with a high probability of hail. They are less strong than casings but can soften the impact.

You can also apply methacrylate to the surface of the panels yourself. It is an inexpensive monomer and a good solution for solar panel hail protection. It creates a protective layer and does not prevent sunlight from reaching the photocells. However, a thick layer may reduce the efficiency of energy mining.

Tip 4: Consider Solar Panels Hail Damage Insurance

The first step is to check your homeowner’s insurance policy to see if it covers hail-damaged solar panels.

If so, you can submit a claim with the collected documents: photos of solar panels hail damage, weather reports, and a copy of the warranty.

By following these tips, you ensure the long-term and efficient operation of the system. Don’t forget about regular inspections by you and the PV module maintenance specialists.

Have any questions left about solar panels and hail damage or how to protect your solar system? Don’t waste another minute — get your free solar quote right away!

GET SOLAR QUOTE

FAQ

Does hail damage solar panels?

Yes, hail can damage PV panels, causing cracks, splits, and reduced power output. Protecting solar panels from hail is significant for maintaining their performance.

How can homeowners identify hail damage on their solar panels?

Homeowners can detect hail damage by finding cracks, splits, discoloration, or reduced power generation.

What if my solar panels are damaged by hail?

In this case, inspecting them as soon as possible is necessary. Contact a qualified PV installer to assess the damage and determine the best method of protecting solar panels from hail.