Inverters convert electric energy into usable AC electricity for our homes. Although solar panels are quiet, some homeowners may hear a humming sound from their inverters, often due to incorrect installation. In this guide, we will explore the causes of solar inverter humming noise and provide practical solutions to address the concern.
Do Solar Panels and Inverters Make a Humming Noise?
High-quality solar inverters are usually noise free because they are made of electronic components and are not equipped with a transformer. On the other hand, older or cheaper inverters with transformers make buzzing and humming sounds, especially under heavy loads. Central and string inverters produce approximately 50-60 decibels of noise, whereas micro-grid inverters are virtually noise free. If you come across any unusual sound from your solar inverter, you must reach out to your manufacturer or installer for assistance.
Solar panel systems are usually designed to be noise-free, even during nighttime. They do not generate any sound, and even panels with moving components are designed to operate quietly. However, in some cases, you may hear a hum during the day when the panels are producing electricity from solar energy. This hum is usually minimal and may come from the inverters and if the solar panel setup has not been installed correctly.
Solar Inverter Humming Noise: Causes and Solutions
Before you purchase an inverter, it is recommended to check the nameplate and data sheet for noise data and then find out how much noise or sound a solar inverter will produce. Apart from the humming noise, the inverter generates different beeping noise that needs to be addressed. Before we move on to the causes and solutions of solar inverter humming noise, let us learn about the different beeping sounds that come from it.
- Four beeps every 30 seconds: It indicates the inverter has transitioned to on-battery mode.
- Single beep once or twice: It means an incomplete on-battery alarm or indication.
- Rapid beeping for 1 minute every 4 or 5 hours: Indicates the battery needs replacement as the inverter failed the self-test.
- One beep repeating every 5 seconds: Indicates low voltage.
So, why is my solar inverter buzzing? The causes and solutions for inverter noise issues are given below:
1. Insufficient Battery Cable Size
Insufficient battery cable size can lead to various issues, including voltage drop, resulting in a high-pitched alarm sound from the inverter. This occurs when the cables are unable to handle the flow of current required by the inverter, causing a decline in the voltage level. This may gradually damage the whole setup.
To address this issue, it is crucial to change the battery cable to the appropriate cable size. If you are not sure about it, you can contact your installer or a professional to ensure that the cable length is sufficient for the correct installation. You also have the option to deactivate the beeping sound through the inverter software by deactivating the UPS audible alarm tones feature.
2. Depleting Battery Capacity
Another common issue with an inverter is depleting battery capacity, which can be identified by unusual alarm-type sounds or noises emanating from the device. Such strange sounds often indicate a decrease in the battery’s ability to hold a charge.
To resolve this issue, start by charging the inverter battery for a few hours and then switching it on to monitor if the noise persists. If the problem continues, you can seek assistance from a professional who can assess and address the underlying cause.
3. Incorrect Installation
While solar inverter humming noise may not be a problem for some people since the inverter is generally kept switched off at night. Still, for optimal performance, it is advisable to buy a top-quality inverter and avoid installing it in bedrooms or near windows.
You can discuss with your solar installer about the installation location and consider positioning it near the electrical switchboard. By placing the inverter outside your building, in a remote area like the garage, any humming sound it generates will have minimal impact.
If you have tried the above solutions but the alarm and the humming sound still persist, it is recommended to seek professional assistance. A qualified technician can examine your battery cable setup for undersized cables and take care of the loose connections powering the inverter.
Also Read: What Will a 750 Watt Inverter Run?
Why Do Solar Panels Make Noise?
Solar panels are generally designed to function quietly but there are a few reasons why you might hear some low-level noise:
1. Inverter Humming
The inverter, which converts the electricity generated by the solar panels, from DC power to AC power can sometimes produce a humming noise. This is more common with string inverters, and the range is usually around 45 decibels. So it often does not bother users and positioning it in an enclosed space can help reduce the noise. Micro inverters typically do not generate any sounds or humming sounds, so if you hear it, contact the installer or manufacturer for help.
2. Inverter Fans
Inverters are equipped with fans to keep them cool, especially if they are exposed to direct solar radiation or have high electricity demand. The fan noise is usually minimal and barely audible. Moreover, to reduce fan operation, install the inverter in a shaded area where it is not exposed to direct sunlight for a long time.
3. Incorrect Installation
So, why do solar panels make a humming noise? Well, improper installation of solar panels, such as insecure mounting racks or loose cables, can lead to several sounds or make a humming noise, especially in windy weather conditions. The common causes of incorrect installation are discussed in detail.
A. Loose Cabling
If the cabling work between the panels is not properly clipped, the connections will not be secured and it can move in the wind creating noise. So, clipping the cabling correctly should solve this issue, and you also get it checked by a professional if required.
B. Loose Racking
Loose mounting racks can lead to panels making rattling sounds and movement in windy conditions. To eliminate the noise, it is advisable to contact your solar installer and ensure that the racking is properly secured.
C. Wind Noise
Solar panels themselves operate quietly but wind flowing through small gaps or spaces can produce a whistling noise. However, as long as the panels are securely positioned, wind noise should not be an issue.
4. Roof Gap
In most solar panel setups, there remains a small gap between the base of the panel and the roof. However, if the roof tiles are not even, wind can generate a wind tunnel effect, resulting in noise. To address these issues, checking for loose tiles and securing the connections can help.
To find out if your solar panel system is making noise or any strange sounds, you can check at night when the inverter is not actively working. If you hear noise, it may be due to loose connections or the inverter. Therefore, for better long-term performance of your solar power system, you must ensure secure connections, correct wiring, and installation to prevent such issues. If you have any doubts, it is best to seek professional guidance to ensure everything is functioning properly.
Also See: What Happens if a Solar Panel is Not Connected?
How to Control Solar Panel Noise
There are several options and techniques available to control solar panel noise. One approach is to consolidate the sound-producing equipment in a particular centralized location within the facility or solar farm. This centralization allows for better control over the output of noise, even if you are not sure about the noise or have limited knowledge about the site. For industrial plants, placing sound-producing components in a specific industrial zone can also be helpful.
Another method involves the employment of noise barriers. Although their effectiveness may be limited for controlling longer wavelength sounds, larger walls may be required to get desired outputs.
To control noise from inverters and transformers, you can employ a forced-air ventilation system to manage the generated heat. However, consider the noise produced by cooling fans during the design phase.
If you come across strange sounds or noise from loose racking, it is likely a result of the correct installation. So, for noise caused by loose racking, contact your installer or a professional technician for inspection and proper securing.
In summary, this blog has discussed the causes of solar panel and inverter humming noise, including incorrect installation, insufficient battery cable size, and depleting battery capacity. We have offered practical solutions to mitigate these issues and ensure optimal system performance. If you need additional support, consider reaching out to a specialized technician or service provider for assistance.
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