What the Guru says
Hello Solar Guru. every sunny day my inverter make a lot of noise. What is it?
So all electronic devices like inverters, they all get hot. What you're probably hearing is the noise of a cooling fan.
Now this might be normal and might just be fine, but it is worth checking a couple of things. It's worth making sure your inverter isn't getting overheated because it's perhaps in the full sun.
It's also worth making sure that you don't have a problem with the cooling fan, so if it's making a lot of noise, get a system check.
Solar power inverters can sometimes make noise during full operations.
The reason is that during such times, e.g. between 11 am and 3 pm on a sunny day, the unit can become hot. Therefore, the cooling fan will operate at a maximum capacity. This then can generate some noise. There can be 3 reasons you might hear noises from your solar inverter or PV system in general.
They are
- The cooling fans operate on maximum: Some inverter models, such as the Fronius models, have inbuilt cooling fans. This is because the fans will dissipate heat generated when converting DC (Direct Current) electricity from solar panels. Into AC (Alternating Current) for use in the house or business. As the fans spin, especially if they have had dust deposits over time, they can make an audible noise. Overall the noise will be louder on sunny days, as in such situations the fans will run faster. As the unit generates more electricity and therefore becomes hotter.
- The transformers make a humming noise: Some inverter models have transformers that help transform the electricity from one voltage level to another. In this process, the transformer can give off a humming noise. The higher the electricity generation, the harder the inverter will have to work. Therefore, the louder the potential hum.
As a general comment, the fan noise and the transformer hum are not shrill or loud but rather in the realm of a background sound – similar to an air conditioning unit or heat pump.
- Poor panel or inverter installation: In some cases, noise issues could develop due to poor installation. Especially the racking and panels. If the panels or racking are not fastened properly or become loose over time. The noise of panels literally moving in the wind could be one of the reasons for solar-generated noise. Also, if the inverter is not securely mounted and has a strong internal fan. This could generate a rattling sound in addition to the fan noise.
How to avoid noise from the inverter?
Here are the steps to reduce the risk of solar inverter noise:
- The correct install position: Ensure the inverter is not installed in full sun. That way, the cooling fan does not have to work overtime, increasing the noise level. Also, try not to put the inverter close to a window where people might sleep during the day. Naturally, when the solar is not working at night, the inverter will make no noise at all, so an inverter can be put close to a bedroom window, as long as the bedroom is not used by a shift worker all day.
- Adequate Ventilation: Ensure the inverter has good ventilation and airflow to prevent heat buildup, reducing the need for constant fan operation. Sometimes the cooling vents on an inverter are too close to a neighbouring unit, such as a hot water tank, reducing the fan’s effectiveness. While inverters have a minimum free space rule – meaning nothing should be around them for approx. 500 mm, some cheap solar installers ignore these rules.
- Have your solar system maintained: Regularly check (e.g., every 2-3 years) that no panels or racking have become loose, and inspection of the inverter will ensure proper functioning.
- Consider the quoted inverter noise ratings in the datasheet: When selecting an inverter, check the manufacturer’s datasheet for noise ratings. Some inverters are designed to be quieter than others. If the noise could be an issue, ask your installer to recommend a model and brand with lower noise.
In summary
While inverters may produce a little noise, the sound levels are generally within acceptable limits and should not cause major issues. However, if the noise from your inverter becomes loud enough to notice regularly, this could be a sign of a problem developing in the inverter. In such a case, you should take a video and send it to your solar installer for feedback.
Should you consider purchasing solar, batteries, inverter or other renewable energy products, we recommend engaging with a qualified local supplier or installer to provide extensive advice. To find the right partner try our company finder and ask our recommended experts to assist you. Using a Your Energy Answers Authorised Partner will give you a well-vetted, experienced, reliable, and trustworthy company to serve your needs.
