Why do solar inverters fail? (Top 5 reason)

By Matthew Joseph Nandirio •  Updated: 10/04/21 •  7 min read

Solar inverters are a great choice when compared to conventional ones. They are green and use the untapped energy from the Sun in a productive way. Moreover, they are usually not hard to maintain. A solar inverter can work up to 15 years on average. You can extend this by at least another five years if you use a micro solar inverter. However, sometimes, they fail before they are expected to. There are several reasons that can cause such failures.

What Happens When A Solar Inverter Fails?

When your solar inverter fails, you would see a lower output. In some cases, there would be no output at all. However, you should know that this can be due to weather conditions.

Solar Inverter
Solar Inverter

For example, if it is very cloudy on a particular day, your device will not be able to produce any electricity. This is because solar devices require direct sunlight to work. Their very working principle is based on the Sun’s energy knocking off electrons from a semiconductor.

Thus, if you think low output may be due to bad weather, you can wait a few days. Once the sky clears up, you can monitor the situation again. If the productivity is still low, it might be a problem with your inverter.

Although inverters do not generate electricity, they convert it to a usable form. Hence, you cannot be certain that lower production means a problem with the inverter. However, if inverters fail, they cause lower output. Also, inverters are more sensitive than other parts of your solar energy systems. Thus, a lower output still most likely implies an inverter failure.

What Are The Reasons For The Failure Of Solar Inverters?

Solar inverters can fail due to weather conditions like high humidity. Also, they can fail if they get overheated while working. This can be due to overuse. Further, they can fail due to improper installation or faulty manufacturing. Another reason could be that an expert does not inspect them in a timely manner.

  • Failure Due To Humidity

Besides reducing the amount of output per unit time, humidity can also cause damage to your solar inverter. Even though the makers of solar devices have placed sealants to minimise environmental damage, consistent exposure can still cause problems. If your solar device is exposed to humidity for a long period of time, it can collect water droplets. This water can seep into the inner parts of your device and cause damage. 

Further, humidity may damage the circuit of your solar inverter. It will cause a short circuit and trigger an alarm. Moreover, the short circuit can occur more than once and in different areas of your device. This is called an isolation fault. It can happen due to factors other than high humidity such as improper cables. If this happens, you will notice that your solar inverter has stopped working. Another less likely possibility is that you may see a very low output.

  • Failure Due To Overheating

Manufacturers design every tool for a certain kind of use. Thus, if you do not use your inverter properly or overuse it, you can cause overheating. It is a huge problem with solar inverters. This is because they are made of electrical parts. In turn, these parts are made of materials that are easily affected by heat.

To combat such problems, the designers have cooling systems in place. Cooling systems usually consist of a cooling fluid. This fluid absorbs the excess heat from the vulnerable parts of the machine. It is able to do so because it circulates at a very low temperature. Thus, when it reaches parts that are heated, the heat from those parts flows to the coolant. Then, the coolant transfers the heat to the sink. After that, it reaches back to the same part which may have heated up again.

However, there are different types of coolants available. Sometimes, the right coolant may not be used with your solar inverter. At other times, it may not be enough to cool the heated parts of your device. Another possibility is that the coolant itself is not functioning properly.

That said, all solar inverters are not liquid-cooled. Some have vents that allow the excess heat to escape into the environment. Whatever the cooling system is, you must confirm that it is functioning properly.

Further, you must ensure that you do not use it beyond its capacity. This can cause failure in the H-Bridge which is a critical part of the solar inverter. Moreover, you should always remember to not switch it on and off many times, if not needed. This will cause cyclic damage and can make the device more prone to fatigue. In other words, it will lower the lifespan of your solar inverter.

  • Failure Due To Improper Installation

This is a very frequent problem with solar inverters. However, there are many ways in which the installation can go wrong. You could connect your inverter to the wrong terminals or calibrate it in the wrong way. Further, you could have a mismatch between the capacity of your inverter and your solar energy system.Thus, the only way to avoid this problem is by ensuring that you call an experienced expert to help you with the installation. In addition to this, you should also test whether your device is working properly once they have installed it.

  • Manufacturing Failure

Sometimes, engineers are not able to manufacture some components to the right standards. The problems with manufacturing can range from metal pouring to finishing. Also, there can be issues with the assembly of the device. This can be as minor as weak soldering. However, some of these issues can cause major damage, including failure. That said, most of these problems are easy to detect.

Thus, you must inspect your device properly before buying. Also, you must ensure that you buy your solar inverter from a trusted source. Further, you should ask for warranties. This will cover you if there is anything wrong with the manufacturing of your device. If you only notice a problem after bringing your solar inverter home, you should call your seller immediately.

  • Failure Due To Irregular Inspection

You must have your solar devices inspected at regular intervals of time. A trained engineer can see signs of failure much before you can. Further, they have the necessary equipment to test the different parts of your device. Most of the testing methods are non-destructive. Hence, they will not damage your solar inverter. Further, they can even repair minor issues before they become worse.

Can Solar Inverters Be Repaired?

Well, yes and no. Most of the time, an expert can repair your solar inverter. For example, if the problem is with the cables of the inverter or if there is a fluid leak. However, sometimes, you may find your device damaged beyond repair. In such a situation, replacement is often better than repair. Also, you should remember to let only the manufacturing company handle your device. If you give it to any other professional, they may not be able to handle it. In fact, they might also cause even more damage.


An inverter is a crucial part of the solar energy system. A damaged inverter would result in a low production of output. While solar inverters can usually be repaired, it is best to take care of your device and ensure that there is no damage.

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Matthew Joseph Nandirio

Matthew Joseph Nandirio is the Founder of walkingsolar. After graduating from the University of Houston in 2002, matt started working as an electrical and electronic engineer for several multi-national solar energy companies. He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research. He now shares his 20 years of expertise through his articles on the walkingsolar website. Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.