25 Common Problems with Solar Panels on Roofs

1. Solar panels are expensive

It is no use denying this. Solar technology is expensive. However, newer technologies are emerging, bringing down the cost of solar panels. Now, you have more choices than ever before. However, if you prefer high-efficiency panels, they are still expensive. 

The price tag of your solar system depends on various factors – your location, availability of direct sunlight, size/shape/tilt/orientation of your roof, your energy consumption, among others. 

The unavailability of direct sunlight means you will need more solar panels to meet your energy needs. Or you may have to choose higher efficiency panels that are more expensive. Another solution is to use tilting mounts of solar trackers to capture the maximum sunlight. 

The more your energy consumption, the higher the capacity of the solar system is needed. And this means more investment. You can use a net-metering arrangement to avoid the extra expense on the battery. 

As solar energy is promoted in a big way, there are so many incentives and rebates available for a solar system purchase. Availing the eligible financial offers can take away the burden of the high cost to some extent. You may also consider leased solar panels to avoid the upfront costs.

Related: Why are Solar Panels So Expensive?

2. Installation cost is not cheap either

Your expenses don’t end with the purchase. Setting up the system is a detailed process that requires the services of a trained professional.  This means more expense.

A solar installation cost can set you back anywhere between $5,000-10,000. You can bring down the installation cost by choosing higher efficiency panels. With fewer solar panels, you can manage the same output. However, the panels themselves are more expensive.

Some solar companies offer free installation of solar panels purchased from them. However, your choices may be limited by this. So, take care to understand the deal before accepting it.

Another choice before you is to install solar panels yourself. However, you should attempt this only if you feel confident that you can handle the workload. If not, you may end up spending more and wasting money.

Related: How much does it cost to install solar panels?

3. Ample roof space is essential

No matter which solar panels you choose, you need adequate space on your rooftop to install solar panels. The more panels you install, the more solar energy you can generate. Large roof space translates to a big house. 

The roofs are the best spots to keep your solar panels as there are fewer chances of shade from overhanging trees and neighboring buildings. If you are aiming to generate enough solar energy to meet all your energy needs, a large roof space with good exposure to sunlight is essential. There is not much you can do to overcome this constraint other than choosing high-efficiency solar panels.

4. Take care not to damage the roof

If installed properly, you can eliminate this possibility. But the prohibitive cost of the panels and installation may force you to cut corners and this can create problems for your roof.

If holes drilled to fix mounts are not sealed well, water can seep in. Another issue you may face is water retention. If the solar panels block the natural drainage of rainwater, it can lead to stagnation of water and consequently solar panel roof leak and roof damage. 

Workmanship matters a lot in preventing damage to the roof. Professional installers equipped with the right tools can do a better job than an untrained person. 

5. Heat fade can bring down the efficiency

Solar panels use light energy in the sunlight to produce electricity. The sunlight also has a heat energy component. If this heat energy gets too much and heats up the panels to high temperatures, the solar panels may not perform at the optimum level. Too much sun is also damaging.

Another reason for heat fade is wiring. Faulty or damaged wiring, both internal and external, in the solar panel installation may lead to the production of heat. 

If the sun’s heat is causing trouble, you should choose a better spot to install solar panels. Periodical checks can help you eliminate trouble from damaged wiring. 

6. Nesting can result in serious damage

Most rooftops are free of human presence and this makes them perfect nesting grounds for a variety of members of the animal kingdom like rodents, squirrels, birds, and critters. For them, the solar panels offer excellent protection from the weather as well as predators. Naturally, they prefer to make their homes underneath panels.

Unfortunately, this doesn’t work out well for the solar panels. Nesting can lead to structural damage and present a fire hazard. Accumulation of waste can bring down the efficiency of panels.

You can prevent this by fixing protective barriers to keep them from nesting under the panels.

7. Dust/dirt/debris build-up affects electricity production

As rooftop solar panels are exposed to the elements, it is natural that their surface gets covered with dust, dirt, debris, or even bird droppings. Anything that prevents sunlight from reaching the solar cells below will affect its efficiency.

Periodical cleaning of solar surfaces can help in managing this problem. In case your solar roof is hard to access, you may have to hire services for this. Or else, you can do this easily with a water hose.

8. Good sunlight = optimum energy production

New generation panels can generate electricity even on cloudy and rainy days. However, the production will be lower than that on sunny days. And this is good enough only as a short-term arrangement. The capacity of the installation was calculated with sunny days most of the year. If this is not the case, the solar system may not function up to expectations.

9. No energy generation at night

This is one of the major drawbacks of solar energy. Without sunlight, there is no solar power. You need to have other arrangements to continue enjoying electricity 24×7. Such as connection to the grid or solar battery. You can draw energy from the grid whenever there is a shortfall. The solar battery can store the excess energy generated during the daytime for use at night.

10. Solar batteries are expensive

The storage battery is one of the options for you to enjoy a continuous power supply. However, they don’t come cheap. A battery can set you back anywhere between $5,000 and $10,000, depending on the capacity of storage. If this is too expensive, your only option is to draw energy from the grid during night time.

11. Manufacturing process is not eco-friendly

The photovoltaic process in itself doesn’t harm the environment in any way. No greenhouse (GHG) gas emission, no air pollution, no excess water consumption, or not even noise pollution. It is one of the rare perfect technologies that you may come across.

However, the manufacture of rooftop solar panels is not so good for the environment. It needs rare earth minerals, is energy consuming and water-intensive, and results in GHG emissions. Ultimately, the decommissioned panels add to the toxic waste, polluting both land and water.

Some of these cannot be avoided with the present technology but as new technologies emerge, we may have a better solution. However, responsible practices for the disposal of old panels and recycling can help in containing much environmental damage.

12. Internal rusting can reduce efficiency

As rooftop solar panels are exposed to weather conditions year-round, there is always a threat of water seeping inside and damaging the solar cells and wiring. To prevent this manufacturers use protective tempered glass on top and seal the panel with waterproofing material. 

If the quality of the material used is not up to the standard or if the sealing is not done well, water may seep inside during rains and corrode the internal parts. This can bring down the efficiency of the panels.

The only way to avoid this is to choose high-quality solar panels from reputed manufacturers.

13. Lifespan of an inverter is less

You need an inverter to convert the direct current (DC) produced by the solar panels into alternating current (AC) that most home appliances need. Good solar panels may last for 20-25 years but the life of an average inverter is 5-10 years, at times even as little as a year or two. Even if you choose the best, it may last you for 15 years. This means you need to replace the inverter at least once during the life of the solar system. 

An inverter can cost between $500 and $2000. To avoid the need for replacing the inverter, you can choose better quality and brand. You can maximize the lifespan of the inverter by choosing its location. Take care not to leave them exposed to the sunlight on the rooftop. Instead, find a cool spot for the inverter inside near the main switchboard.

14. Potential-induced degradation (PID) effect

PID effect is potential-induced performance degradation in crystalline PV modules triggered by voltage, heat, and humidity. This undesirable phenomenon can result in a substantial loss of energy generated. Preventing overheating and maintaining low humidity levels can help in mitigating this problem. Installing an anti-PID box also is helpful.

15. Appearance of snail trails

No, this has nothing to do with slimy creatures though it would look as if snails have crawled over the panels. This problem usually crops up after a few years of use. And it goes much deeper than the lines that appear on the surface.

Low-quality sealing of rooftop solar panels may result in water seepage through the back sheet. This can diffuse slowly to reach the surface of the cells. The moisture would cause a breakdown of silver in the grid fingers and appear as snail trails. Though this in itself may not affect cell performance, this can worsen into deeper cracks in the solar cells, creating potential hotspots and thereby deterioration in performance. 

Careful handling of solar panels and better waterproofing are the solutions to this problem.

16. Formation of microscopic cracks 

As the rooftop solar panels are getting thinner, they tend to be brittle and develop cracks easily. These microcracks can bring down the efficiency of the solar panel drastically. They have the potential to develop into deeper cracks and hotspots. It is recommended to attend the microcracks as early as possible. 

17. Creation of hotspots

Usually, hotspots form on solar panels as a result of poor workmanship. Mismatch, poor soldering, or cracks in solar cells can lead to the development of higher resistance and overheating. Hotspots show up as burnt marks or brown spots on the surface of the cells. 

Hotspots, if left unattended can lead to underperformance and even a fire. Replacing the panel is the only solution to this problem.

18. Broken glass of the solar panel

The function of this glass is to protect the solar cells inside from damage from weather or heavy force. Usually, high-quality tempered glass is used so that it will not break under pressure. However, cost-cutting and poor manufacturing standards may lead to the use of substandard glass panels. 

Broken glass can impact the energy output. Replacing the entire solar panel is the only solution.

19. Substandard soldering

The solar cells in a solar panel are connected into strings and the connection is soldered before sealing it with waterproof material. Poor quality soldering can lead to some of the cells becoming open-circuited. This can bring down the energy output of the solar panel substantially.

There is no way to repair this issue. You have to go for a replacement. However, you can prevent this issue at the time of purchase by choosing a high-quality solar panel. 

20. Defective junction can reduce energy output

A solar panel has a junction box at the back to link it up to the solar installation. This has to be sealed well to prevent rainwater and dust from seeping in. If the seal is compromised, the moisture or dust can damage the bypass diodes, leading to short-circuit.

A burnt bypass diode can create an open circuit and prevent the energy generated from flowing out. Choosing an IP67-rated junction box is the only solution.

21. Cracked back sheet results in poor insulation

The purpose of the back sheet is to protect the solar panel. However, poor material selection, manufacturing defects, or exposure to severe weather can lead to the development of cracks in the back sheet. This means water and dust can enter the solar panels and cause damage to the cells as well as internal wiring. The only solution is the replacement of the solar panel.

22. Solar meter is faulty

A solar meter doesn’t directly affect the performance of rooftop solar panels. Though you need them to know your daily energy production and usage. A solar meter may break down with time or it can be just a glitch. But when it is not working, it would make it difficult to assess the performance of the solar system.

A faulty solar meter doesn’t imply that there is an issue with your solar panels. You need to get a technician to assess the problem and rule out problems with solar panels. Some faults in the solar meter can be rectified. Sometimes, you may have to go for a replacement. 

23. Burnt terminals in solar battery

With use, the terminals of a solar battery may corrode. This can have serious consequences if left unattended. However, burnt terminals don’t imply that you need to replace the whole battery. All you need to do is to change the metal pieces of the terminal and the battery is good to go again.

24. Issues with electrical wiring

Solar panels can be connected in series or parallel. A series connection involves linking the positive terminal of one panel with the negative terminal of the next and so on. In a parallel connection, all the positive and negative terminals are connected together. Both come with their own set of problems. 

In a series connection, the underperformance of one panel can affect the overall energy output. In a parallel connection, if the wires used are not thick enough, the high current generated can damage the electrical connection.

25. Manufacturing defects in solar panels

Internal defects in rooftop solar panels can develop at various stages – at the time of manufacture, during transportation, or during installation. To avoid this, it is recommended to check the solar panels for defects by inspection as well as by assessing their performance. In case of a defect, you should ask for a replacement without delay.

Troubleshooting a solar energy installation

Checking the solar meter for any drop in energy generation is the easiest method to figure out if anything is wrong with the installation. In case you detect a drop, you can try these steps to pinpoint the problem.

• See if the rooftop solar panels are receiving direct sunlight or if anything is blocking the sun. It can be an overhanging tree branch or accumulated dust or debris.
• Examine the breaker switches. They may trip due to a power surge.
• Check if the green light is glowing on your inverter. If it is not, contact the support.