How to Control Unusual Noise in Your Solar Panel Installation

One of the most remarkable benefits of having a solar panel at home is this: The panels are specially designed to operate without making noise. Despite this, some solar panel users have reported hearing noise at night- coming from their panel system. Well, of course, since the sun doesn’t shine at night, it might seem that the noise is coming from the panel system itself.

This raises the question: Is it true that solar panels actually make noise at night? Well, you’ll discover that the panels themselves may not be responsible for such noises. Hence, if you hear some humming during the daytime, consider this as perfectly normal. But, if you hear noises at night- and you’re sure it’s coming from the solar panels- then that’s an entirely different matter- it means there’s a problem somewhere, and it must be solved.

So, what solutions are available to deal with this problem? We’ll soon find out.

Yes, it’s Possible – Your Solar Panels Can Produce Noise at Night

As the world increasingly seeks to be green, it’s clear that gas and coal-powered plants are gradually getting replaced with environmentally-friendly, renewable sources of energy. These include wind and solar energy. Overall, experts consider solar energy to be a quieter alternative that’s fast gaining popularity.

At first, you might think that solar energy facilities do not generate any sound at all. Why, it doesn’t have large moving parts (compared to a wind turbine’s large blades, for instance). Moreover, it doesn’t operate with the typical explosive processes you’d expect with gas combustion, for example.

Instead, the most visible parts are the large solar panels- and these do not produce noise in themselves. Regardless, there’s noise-generating equipment that comes with solar facilities. These may be conspicuous on small concrete pads.

Observe Local Regulations with Your Solar Installation

As noted, solar panels should be noise-free- particularly during the night. Thus, we would not expect any noise to come from these panels at night in a normal situation. Of course, solar panel users are accustomed to a humming noise produced by these devices during the day- this is perfectly normal. Even so, the sound produced is not usually loud or unnecessarily distracting. Unless you’re outdoors or near the panel (about 50 feet), it should be barely audible.

It’s essential to note that you must operate and design it to comply with the local municipal and state codes if you operate a solar farm. This is a natural requirement for any industrial or energy-generating facility. You might find some of the limits imposed as routine or outright challenging for a typical solar facility.

So, what are some possible causes of nighttime noise experienced with some solar panel facilities? It’s essential to know this in order to determine a viable solution.

Possible Causes of Nighttime Noise in the Solar Panel System

While some hardware that makes solar facilities are noiseless, others might produce broadband sound with considerable tonality. PV solar modules, for example, generally produce direct current electrical power. If you’re storing energy within a DC battery, this is okay.  But transferring such electrical power over to the power grid requires the DC power to be converted to AC (alternating current). An inverter is used to complete such a process.

Furthermore, this process demands the use of fast switches to change the polarity (electrical flow direction). Generally, AC power usually cycles some 60 times per second (60 hertz); the switches used should activate twice for each electrical cycle. This process causes tonal sound. The sound is produced at twice the electrical line frequency (or 120 hertz). Moreover, your solar panel’s transformer facility is activated to initiate the voltage for easier transfer into the local power grid. Hence, the solar transformer system has three primary sources of noise:

  • Fan noise.
  • Coil nose.
  • Core noise.

The core (as well as coil) noise result from electromagnetic forces occurring twice for every AC power cycle. Just like with other inverters, this process is the source of a 120 hertz primary sound. This also causes harmonic sound. The cooling sounds, which are usually mounted outside the transformer, are the third source of sound. Experts recognize the cooling fan as the most significant source of A-weighted (broadband) sound.

How to Control Solar Panel Noise

If you want to control the noise in a solar panel facility, you can pick from a few options. One of the easiest and inexpensive noise control method is to place the specific sound-producing equipment in a central location at the facility or farm. Actually, this is the best place to control the sound output, even if you know nothing about a specific site. Secondly, if you’re running an industrial plant, simply place the sound-producing components on the industrial-zone. It’s beneficial to do this.

The other noise control method involves the use of noise barriers.  Be cautious while using noise barriers- they are known to be less effective for controlling longer wavelength sound. They also require you to use a larger-than-ordinary wall.

But there’s an effective, simple sound-control method that works excellent for inverters and transformers- Use a building or a full enclosure. Since both devices generate heat, you’ll need a forced-air ventilation system. Why? The fans used in such cooling systems are louder (using the A-weighted basis) than the hardware’s electrical side. Always keep this in mind, particularly during the concept design phase.

How to Control Inverter Noise

Not all inverters produce noise or a humming sound- much depends on the inverter brand or quality. String inverters cause such sound (at a maximum of 45 decibels). This kind of hum is whisper-quiet-generally silent.

It’s advisable to locate the equipment in an enclosed garage or such other space to control any noise from the inverter. Microinverters do not usually produce such sound. If the noise persists and you determine it’s from the panels or inverter, consult your installer or manufacturer for help.

Dealing With a Wind Panel’s Loose Racking Noise

Occasionally, you might discover that the installer racking is not screwed into the roof rafter well enough. This might simply be shoddy workmanship. But sometimes it just happens.

It means the racking is possibly loose or unstable. This might be causing the racking to shake and move around. It might even blow and disconnect when there’s a strong wind. In this case, call your installer to check the system and ensure everything’s fine.

Conclusion

Aside from a minimal inverter hum and the occasional new wind noise, your solar panel system should generally operate noise-free, even at night. If you’re experiencing some noise or disturbance (particularly excessive noise), we recommend that you get the system checked as soon as possible. This will protect you from running into issues with your valued solar panels. Use the tips suggested in this post to deal with other potential noise issues with your solar panel system.

3 Comments

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Holly Masterreply
June 30, 2021 at 10:44 pm

My neighbour’s battery solar system sends vibration and whirring noises through the room next to it which happens to be my bedroom. I cannot sleep and the sound is making me ill. What can I do?

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sarah taubitzreply
August 19, 2021 at 11:51 pm
– In reply to: Holly Master

You need to search for an acoustics consultant, preferably one that is in the National Council of Acoustical Consultants (www.ncac.com) and/or who has experience with audible tones and vibration. Good luck!

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Carolynreply
July 16, 2021 at 2:23 am

Hi Holly,

I have been searching the internet to find someone else who is experience vibration and sound from a solar system. I have installed an off-grid solar system. I am waking to high frequency sound and vibration. Some nights it is constant throughout the night. I actually feel like I am vibrating! Most nights there is no such interference, however. I downloaded a Ultrasound Detector app. The app shows that, when I am hearing the very high pitched sound, sound frequencies of 19 kHz and higher are up to 50 dB in my bedroom. I have used the app to try to find the source of the sound and it appears that it is coming from the solar electricals in the garage as the sound increases to over 60 dB when I am in front of the unit. These same frequencies occur at between 10 and 20 dB when I am not hearing the high pitch sound, according to my app.

Can anyone make any sense of this?

Thanks
Carolyn

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