Four Most Common PV System Failures And How To Fix

Home Four Most Common PV System Failures And How To Fix

With a greater public acceptance of Solar PV and fossil fuels becoming an increasingly hot topic in the media, a lot of people out there are considering going solar. The problem is, installing a solar power system is not always as easy as it seems. Here I’m going to look at some of the most common reasons why solar Photovoltaic systems fail, and some safety tips you can follow to prevent problems down the road.

There are a lot of ways your solar power system can fail, especially if you haven’t put in the time to learn how they operate. And we understand that keeping up with technology can sometimes be overwhelming, especially if it’s not your specialty. But fortunately, there are a few simple tips you can use to ensure that your system will work properly.

In this blog, let us discover the Four Most Common PV System Failures And How To Fix.

Hot Spot

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When a solar panel is shaded, the current cannot flow around weak cells, causing the hotspot effect. The current will eventually concentrate in a few cells, causing them to overheat and melt.

One of the most prevalent reasons for solar-panel failure or fire danger is the hotspot effect. As a result, it’s vital to utilize bypass diodes when constructing photovoltaic systems to guarantee that current may flow past weak cells while shading impacts are reduced under diverse shading situations.

Hotspots are still widespread in today’s PV modules, and this trend is expected to continue as PV module technology advances to thinner wafers, which are more susceptible to micro-cracks throughout the production, shipping, and installation processes.


Hot patches on the surface of solar modules are widespread, and they use a large amount of the module’s power.

At this time, we know that thrown shadows produce hotspots. So, where do cast shadows come from?

  • Shade from an item near or above a solar panel, such as trees, people, or equipment, is one cause. Another typical reason is an obstruction on the glass surface caused by dirt and debris, which stops light from entering the cell by reflection.
  • Design flaws in some kinds of silicon cells, known as multi-crystalline or poly-crystalline cells, may also result in hot spots.
  • Hot spots may have a major influence on nearby cells as well as effect/damage solar power output if they are not discovered in a timely way.

How to Fix

Maintain enough airflow.

Hotspots don’t just pop up out of nowhere. Heat accumulation, which may be caused by a variety of circumstances, is always the cause. However, if your solar panel system has little airflow, such as a protective cover, hotspots are more likely to form.

To prevent overheating the panels, a good solar panel system will constantly provide appropriate ventilation and circulation. Installing a power optimizer that automatically limits energy output when temperatures climb too high is the best approach to avoid overheating.

This eliminates the need for manual controls and guarantees that your production standards are maintained.

Bypass diodes should be used.

The use of bypass diodes on each solar panel may even avoid the formation of hotspots. The absence of bypass diodes on solar panels often causes hotspot effects. Bypass diodes enable current to flow in the event of a fault or shading, preserving power output.

Good thermal qualities for the glass and back sheet

Instead of just absorbing heat, manufacturers may utilize varieties of glass with specialized qualities that can lower it. It’s also a good idea to utilize a high-thermal-conductivity back sheet to help the panel disperse heat more efficiently.

Dust and filth should be removed.

Hotspot effects are more likely to occur on a filthy or dusty solar panel. Cleaning the panels on a regular basis might assist to mitigate this impact.

It’s also a good idea to check that no trees, leaves, or other debris are blocking sunlight from reaching your solar panels.

Use solar tracking equipment to keep an eye on the sun.

Instead of just allowing solar panels to sit in one place, solar tracking systems actively move them to face the sun.

By exposing your panel to direct sunlight throughout the day, these solutions assist to prevent hotspot impacts. The disadvantage is that these tracking systems are costly, and the extra moving components necessary for this system type will raise your power production prices.

Install panels at a 45-degree angle.

Hotspot effects may be reduced by installing your panels at an angle. On the internet, you may locate the ideal angle to utilize for your location.

Remove any obstacles from the installation of the panels.

Installing your panels without impediments is a simple and efficient approach to avoid hotspot impacts. This implies they shouldn’t be too near together or in the shade of anything else since shadows will form on each other.

The most typical obstacles to be wary of are trees and buildings. It’s also a good idea to place your panels away from any shadows.

PID Effect

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PID (potential induced deterioration) is a phenomenon in the solar sector that has just lately become a problem. PID affects the ions in a solar cell, resulting in a reduction in the cell’s output.

Within the first year of operation, PID may dramatically limit the power output of a photovoltaic (PV) module, with power losses at the module level as high as 70% in the first 18 months. These losses at the module level may proceed quickly and become so severe that they impact the overall performance of a system.

Potentially caused deterioration is sometimes mistaken for a module problem, but it requires system-level modifications. The incidence of PID is mostly determined by the system’s electrical setup and module design/construction. PID may be caused by a variety of factors, including system voltage, temperature, humidity, and irradiance.


PID arises in systems with a large negative potential compared to the earth. This occurs when the inverter’s negative pole is unconnected to the ground, or when the inverter’s positive pole is connected to the ground in a bipolar configuration.

PID does not occur in grounded systems, where the inverter’s negative pole is grounded, or in systems with a voltage less than or equal to 600V, since the high negative voltage potential that causes PID does not exist.

Unfortunately, owing to lower prices and increased efficiency, grounded systems are losing way to ungrounded and bipolar systems, and higher voltage systems are becoming more widespread as a result of recent regulations.

The PID impact is particularly severe in the modules with the largest negative potential in an ungrounded system.

There are various elements that, in addition to the electrical arrangement, might generate the correct circumstances for PID to occur:

  • Design of modules
  • Construction
  • Quality Control

What occurs (or doesn’t happen) in the production plant has a big impact on whether or not PID develops in a particular panel.

How to Fix

PID may be safely avoided in solar plants with grounded electrical layouts by grounding the negative pole of the inverter.

The PV industry has developed a set of tests known as IEC62804 that may be used to assess dependability. Anti-PID procedures should also be introduced at the inverter, according to HSB experts, until there is enough data to indicate that module certification are successful.

Improper mitigation efforts might cause harm to the plant’s equipment and breach various manufacturer warranties.

Plant-by-plant mitigation strategies may differ, however they may include:

  • Changes to the facility’s electrical configuration
  • Modules must be replaced.
  • extra equipment installation, or
  • a mixture of the above

The time it takes to discover, confirm, and mitigate PID varies depending on the length of talks between suppliers, operations and maintenance (O&M) providers, engineering, procurement, and construction (EPC) contractors, owners, and developers.

Many sources claim that PID impacts are reversible and that if the proper mitigation measures are applied, the modules will begin to recover, however, this is not always the case. Some modules have improved under carefully controlled laboratory circumstances, although this is dependent on the degree of the power loss at the time recovery began.

Modules with minor power losses of less than 10% usually recover, while those with substantial power losses of more than 30% are unlikely to entirely recover. The method for addressing PID’s consequences may have a big influence on plant performance in the future.

Currently, there are two industry-accepted PID mitigation options:

  • Equalizers with a charge, and
  • Grounding with a high impedance

The approach to utilize is determined by the system’s design, cost, and compatibility. To avoid voiding the equipment or system warranties, any PID mitigation solution must be authorized by the inverter OEM, module OEM, and EPC contractor.

Option 1: Add equalizers to the mix.

For transformerless inverters that cannot be grounded, a charge equalization, such as the PV offset box, may be utilized. Because PID is caused by a large negative potential relative to the ground in an ungrounded or bipolar system, the charge equalization operates by providing a reverse charge to the string at night.

The charge equalization gives the modules a high positive potential (inverse voltage) during the day and a strong negative potential at night. The polarization effect that happened during the operation is now reversed.

A charge equalizer will not enable the module to fully recover. At the module level, there might be a permanent power loss of 5%. This, however, will frequently go unnoticed at the system level. This procedure has also been successful in regenerating the majority of modules that have been impacted by PID for a long time. Modules that have been severely impacted, but have lost more than 50% of their power, may not entirely recover.

Option 2: Grounding with a high impedance

A high-value resistor may be used to ground a transformerless system at the negative pole of the inverter (e.g. 22kOhm). Grounding with a high impedance is referred to as high impedance grounding. Ground fault detection necessitates the installation of additional devices.

This approach lowers the string’s voltage potential, thereby halting or preventing PID. However, recovery of PID-affected modules will be less effective than with a charge equalization.

Inverter Problem

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Before you begin troubleshooting a solar inverter, you must first understand how it operates. Here’s a quick rundown of how the inverter converts DC energy from the panel into AC power:

The energy from the solar panels will be stored in the battery, which will be charged directly from the roof’s PV cells. The inverter comes into play during this process, converting the power type from DC to AC and storing it on the battery. The DC electricity from the panel is sent into the inverter, which is the procedure in basic math. The inverter transforms it to AC and stores power in the battery until it is needed. When you switch on the light, it also pulls AC power from the battery through the inverter.


The inverters were installed incorrectly.

Because solar inverters are designed to provide years of trouble-free service, they are built to withstand issues. However, this is only true if you install it correctly, with no bad connections or yields. As a result, the majority of internal issues with solar inverters are caused by improper installation in the first place.

The inverter is constantly beeping.

There are two main causes for your inverter to beep: one is that you have run out of battery, and the other is that you have overloaded your inverter.

If you overload your inverter above its rated capacity, the inverter will most likely shut down on you. Your entire load demand should not exceed the inverter’s rating, but you should leave some space above it.

If your inverter is always running at maximum capacity, it may result in decreased efficiency and performance. It may possibly fail sooner than expected. This is also true of low-cost inverters, which often can’t handle more than 80% of their rated capacity load.

When the inverter becomes overloaded, the LED begins to flash (usually accompanied by a consistent beep).

Overheating inverter

One of the most typical concerns with solar inverters is overheating, which isn’t a good indicator of service. The inverter’s high temperature might have a negative impact on overall service and energy output. If the heat exceeds the maximum operating temperature, the system may be shut off.

How to Fix

  • Make sure the installer is a professional with appropriate expertise before you choose someone to install or repair the inverter. Check to see whether everything is operating at the correct power level, as specified by the manufacturer.
  • The first step is to disconnect or turn off any device that isn’t in use! Then, if your device has one, hit the reset button or unplug and reconnect the power.
  • Checking for ventilation on a regular basis is the best strategy to handle the temperature issue. If you’re installing the inverter in a confined space, ensure there’s enough ventilation to keep the space cool. You must also provide a decent cooling technique for the inverter, depending on its kind and size. For the greatest results, install cooling fans in the switch cabinet and create an airflow pattern.
  • Now that you’re aware of the most frequent inverter difficulties and how to resolve them, you may do so at home. If the situation is beyond your understanding, you should get expert help for the inverter not functioning.

High Grid Voltage Issue

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There is a lot of fear-mongering about how renewable energy threatens our power grids, but a real issue that isn’t getting enough attention from the industry is how voltage rises on our mostly old and inflexible infrastructure preventing customers from getting the most out of their solar PV installations.

Of course, anybody who has been educated in this field already knows this, but I’m guessing most customers are unaware of how crucial the link between the voltage at the inverter and the voltage on the grid is. When anything goes wrong, the client receives a bill that shows considerably less power was exported to the grid than anticipated, and someone — a solar installer, an electrical retailer, or a network – receives an irate phone call.


To push electricity out, the inverter must be operating at a greater voltage than the grid (current flows from a point of higher voltage towards a point of lower voltage, never the other way around). The issue is that every solar installation that pushes power into the system raises the network voltage slightly – and with tens of thousands of systems coming online on SA Power’s network each year, some systems will be confronted with a grid voltage that is outside inverter tolerance (the AS/NZS 4777.1 standard limits inverter voltage to 255V).

How to Fix

  • Installing a three-phase inverter is the best option since the current fed into the grid is split into three wires instead of just one with a single-phase converter. The voltage will be reduced the lower the current can be made.
  • Upgrades to the grid, including the replacement of powerlines with thicker ones that contribute less to voltage growth.
  • Increasing the grid’s voltage allowance to manage the greater voltage generated by solar.

Basic Steps to troubleshoot your PV System

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Because the majority of households install solar photovoltaic (PV) panels to save money, the most apparent method to tell whether they’re functioning is to check your power bill. Something is awry if this month’s statement is much higher than last month’s.

Below are the basic steps to troubleshoot your PV System

Step 1: Check your breaker switches first.

Isn’t it annoying when your phone tech support asks whether the computer you’re attempting to fix is plugged in and switched on? It’s demeaning. However, these customer service representatives must inquire since an “off” PC is one of the most prevalent causes of a user’s computer not operating.

Breaker switches, or the little fuse boxes that govern your home’s electrical flow, are the same way.

These switches may be tripped by surges, malfunctions, or overloads, stopping solar energy from charging appliances or being fed into the grid. However, restoring them to their original form is frequently sufficient to resolve the problem.

Step 2: Look for Barriers

Because solar panels need direct sunshine to create electricity, it’s critical to maintain them clear of anything that might obstruct their production, such as:

  • Trees with new leaves that may be obstructing light. You may need to prune some branches if this is the case.
  • Dust, dirt, and pollen that has accumulated over time and are preventing sunlight from reaching your PV panels. Here are some free cleaning recommendations for solar panels.

You should also look beneath the panels for any obstacles. Mice, birds, and other vermin may damage the components of your PV system, resulting in lesser energy output. As a result, it’s critical to remove any feces and dirt. It’s also a good idea to put a pest guard to keep pests at bay in the future.

Step 3: Make sure your solar inverter is working properly.

Almost every PV system includes an inverter, which converts the direct current (DC) power generated by your solar panels into alternating current (AC) electricity for use by your home’s appliances.

  • It’s operating if the light on your solar inverter is constant and green. You don’t have to do anything.
  • If the light on your inverter is yellow, red, or flashing, there is a problem.

Step 4: Take a look at your solar meter.

Solar meters are in charge of recording the energy generated by your PV system in real-time. This helps you to discover abnormalities by comparing historical production data to present data. Solar meters are often the first (and only) line of defense against wasted savings for many households.

Step 5: Install Solar Monitoring 

You should be able to identify most performance concerns early on if you have a functional solar meter and remember to check it on a regular basis. You must, however, keep in mind. You’ll also need to maintain track of historical data in order to put current solar output figures into perspective.

This kind of attentiveness isn’t always feasible for the ordinary homeowner.

Installing solar monitoring is a better option (or fixing your current monitoring setup). For example, at Stable Solar, we provide comprehensive solar service and membership programs that include:

  • Run in the background, monitoring the production of your PV system in real-time.
  • Allows you to access performance statistics from any computer or mobile device.
  • To establish the health of your solar system, examine your historical generation statistics, local weather conditions, and what your neighbors are producing.
  • Send out notifications when your PV system’s output deviates from its regular range.

Tips for a Healthy PV System

Tips to a Healthy PV System
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Solar panels do not operate equally well in all situations, but you may enhance the efficiency and output of your solar system layout or array by taking proactive measures. You can get the most out of your solar investment by following a few easy steps. These four recommendations may help you optimize the output of your solar panels and save money on electricity, from placing them for best power production to qualifying for utility rebates and green energy awards.

1. Remove any shade:

 Solar panels are meant to perform best when they are exposed to direct sunshine. Your array’s output might be drastically decreased if the sun is blocked out by a tree or another structure. Shade is especially harmful to solar panels using a “string” style of the inverter, which restricts the array’s output to the intensity of the weakest panel, according to Energy Sage. Even if just a tiny portion of your array is shaded, the output of the whole installation may be reduced.

Trees should be pruned or removed from the area around your array. If trees cannot be removed or a component of the structure casts a shadow, Energy Sage advises utilizing a microinverter or power optimizer inverter to enhance output from the array’s unshaded areas.

2. Face the Sun: 

When solar panels are facing the sun directly, they create the most energy. Solar Reviews claims that panels facing straight south would get the most direct sunlight throughout the day and have the maximum potential output. In the afternoon and early evening, a more westerly position provides greater power.

The ideal solar panel orientation is determined by how and when you consume energy, as well as how much your electricity costs.

When a utility offers 1:1 net metering, which is the practice of the utility providing full-price billing credits for excess electricity produced by a customer’s solar system, south-facing panels may be the best option. The aim is to generate as much electricity as possible at all times of the day.

If the utility uses the time of use billing, which charges higher rates when the most power is used, you’ll need to pay closer attention to when the most power is utilized in your company or home. A south or southwest direction could be preferable in this scenario.

3. Keep it Clean: 

Dust may build up on your solar panels over time, reducing their performance. Dust accumulation, according to the National Renewable Energy Laboratory, may diminish your array’s performance by as much as 7% over time.

4. Solar Power Tax Credits and Refunds:

Because solar power is healthy for the environment, the government grants tax credits and rebates at the state, municipal, and federal levels. Incentives for new installations may be available from your local utility.


Having a PV system that fails to perform is never a great feeling, but it doesn’t have to end your PV system installation. By using some of the simple assessments and solutions we’ve outlined to diagnose and repair common failures, you can get your system back up and running in a snap. And months later when you experience your first power bill, you’ll know that all the hard work was worth it.

So there you have it, the most common system failures and how to fix them. Hopefully, these tips will allow you to avoid some system failures at home. If they do, please let us know on our ZBeny Page. We would love to hear from you!

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