A solar inverter is like any other electronic device in your home and it will produce some Electromagnetic radiation and potentially Radio Frequency interference. There is a standard that all approved electrical devices in Australia are required to meet (C Tick) but it does not guarantee zero emissions.
The school is out on exactly what harm can occur to human beings from electromagnetic radiation but solar inverters do emit it, so if you are concerned ensure that your inverter is installed well away from living areas – as a rule Electromagnetic Radiation drops off very quickly as you move away from the source and is reasonably easily blocked by obstructions.
As a general rule, the biggest problems stem from Radio Frequency interference on AM or HAM radio because they rely on weak and variable signals with large antennae, which are particularly susceptible to interference of any kind but it doesn’t rule out solar for radio buffs.
Good installation practices to minimise EMR and RFI
The number one rule for EMR and RFI prevention are first and foremost – determine the real cause. Is it the inverter or something else? A simple hand held battery powered AM radio is a great tool to determine where interference is coming from.
Once you have found your source you can then revert to the golden rules – shielding, cancellation, filtering and suppression. Careful routing and location of the DC cabling (twisting them is a good general tip too) is a good idea and the location of the inverter can make a big difference.
Although it is dangerous to generalise, lower cost inverters (or other products such as power supplies) tend to have less filtering and EMR/RFI reduction equipment built in and are likely to cause more interference. Some quality inverter web sites talk about their testing and the lack of EMF that is produced as a result of clever design; so some companies clearly invest more heavily in these types of issues.
So if you are really concerned about RFI or EMR, then I would strongly advise paying a few hundred dollars more to upgrade to an SMA / Aurora / Delta or other top quality European inverter from a brand that has had decades to tweak their designs. And make sure you ask the installer about the issue to weigh up his experience of this issue.
Reducing radio frequency interference is, at best, a “snipe” hunt but choosing quality gear and using installers who understand the issue will go a long way to minimising any impacts.
About Finn Peacock
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my solar system when it first starts up and is closing down is interferring with my foxtel reception. the television makes a buzzing sound and a thin line appears on the screen at the same time. the sound is the same noise that is coming from the inverter, the inverter has been moved farther from the television but has not fixed the problem, do you have any suggestions or have you heard of this problem before thanks peter
We recently had a solar system installed by a reputable company. We have a 5kw inverter. We are being blamed for problems with neighbours dial up internet and anything else that is going wrong electronically in our street. We have found that our AM radio is effected in our house only. Are we receiving the blame for problems that aren’t our concern?
Hi Sheryl,
Your inverter cannot affect your neighbours dial up internet!
Please ask the internet provider to send me the technical reasons for blaming solar for his crappy internet connection, I’d be fascinated to hear them.
Yes, they can affect AM radio in your home. A toroidal magnet over the AC supply can sometimes help this. It looks like a hollow tube that clips over the outside of the wire. Costs about $2.
It’s possible that the RFI interference is due to 700mhz narrowband from 4G plus and 5G low band, you can also expect it from the upcoming 900mhz IOT that will be recklessly deployed by telcos who do not test for standing wave interference at the receiver point.
the interference from a solar inverter is nothing compared to the Narrowband Particle accelerators that are deployed on every rural hill
Only way to know for sure is a spectrum analyzer and a transient power recorder.
Regards
Google “NBN: Mitigating Amateur Radio Interference to VDSL2”
My initial experience is even with my transmitter set to its lowest power (1watt) and connected to a dummy load (no antenna) hitting transmit would drop my NBN.
VDSL2 is very susceptible to external interference depending on the phone cabling.
I had to make a twisted pair NBN modem cable with a common mode choke on the modem cable and on its power supply cable
So to me it’s totally believable that a very RFI noisy solar inverter could affect a neighbour’s internet.
I’d supply a copy of that document along with the suggestion to try a twisted pair modem cable with a common mode choke to your neighbour. tell them to pass the info on to their internet provider.
These cables aren’t hard to make and aren’t expensive, but I don’t know if any that commercially made.
Your solar system can affect your neighbors wireless internet connection!
how? I have tried to find evidence of this to no avail
It most certainly can. The RFI that spews from low grade inverters travel along the wiring, which creates an Antenna. If the radiated signal from your panels interrupts the data signals in the wifi spectrum, it will cause packet loss, which means poor connection or slow speeds.
If you do not believe me, try this. Loosen the input connector to your cable box but dont remove it. While its loose, wiggle the cable wire and connector and watch what happens to your tv picture. The picture breaks up because the electrical noise you are generating by the poorly shielded connector is stronger than the signal and causes the cable box to not be able to properly decode the data packets.
Hi Finn,
I am putting a 5Kw Fronius 3 Phase inverter on the wall in my garage, the only concern I have is that my study and PC are on the other side of the same wall. Can I use shielding like Aluminium foil or copper mesh to create a primitive Faraday cage and shield my PC from any EMR? My other concern is that this could promote arcing from the incoming DC cables.
Your thoughts,
Marc
Great question – short answer – I don’t know! I’ve asked around and I’ll let you know when I get an answer. Watch this space…
Thanks Finn, I’ll keep an eye out for your reply.
Marc
Hi Marc,
Here’s the reply (I don’t think RF will be an issue):
“I do know of one Sungrow inverter that messed with radio signals out in a rural area, and Enphase and particularly Solar Edge regularly mess up tv signals. (MLPE near the aerial).
I’ve never heard of an issue with Fronius and we have installed and monitor about 180 Primo’s and Symo’s to date.”
Hi Finn,
We are having lots of trouble with our Enphase inverter affecting our neighbours TV, do you know of anyone that was able to successfully resolve this? It is starting to cause some tension.
Thanks
Anna
Hi Anna,
I asked Enphase about this they said:
“This issue has now been resolved. It’s not an overly widespread issue but it does occur in some cases where poor TV reception is in play before the solar installation. It is resolved by improving the tv signal by replacing the antenna with a modern one.”
Enphase say they will happily resolve your issue for you – just ask your installer to advise Enphase about the issue.
Any issues – let me know and I’ll ask Enphase to contact you direct.
Finn
Hi Finn.
To get ‘approved’ status, CEC approval – listing – for grid connect inverters, requires certification by ACMA for EMC and EMR.
Are there inverters being connected that do not meet the ASNZ standards for EMC / EMR ?
Finn.
Thanks for your response but, it doesn’t answer the question.
Are inverters being connected (sold) that do not meet the ASNZ standards for EMC/EMR. ?
We recently had a SolarEdge inverter system fitted. Since then we have had TV and radio interference, especially in the middle of the day when the inverter is working more or less at capacity. The original installer then moved our antenna slightly which made a slight improvement at the beginning and end of the day. Today we had a new digital antenna fitted at the rear of the house, further away from the inverter. Again it improved things but we still get interference in the middle of the day, making several channels unwatchable (although interestingly, different ones to previously). The supplier, a reputable company, has been supportive through this process but states they have not had any other customers report this problem with SolarEdge and the antenna guy today, who is also a solar installer, stated he had not seen this problem before. The SolarEdge paperwork does however state that there may be interference. I am not sure if this is because SolarEdge has microinverters or what is the cause??
Hi
Did you resolve this issue? I’m interested because I too recently had a Solaredge inverter installed and have lost all ABC channels ie those with weaker signals in Perth. Tv guys came today and were nconclusive, so I’m left up in the air still!
Hi
Did you resolve this – this is exactly the same issue we are having with SolarEdge system.
Cheers
Hi Finn,
I am a Ham Radio Operator and would like to know what is the up to date brands you would recommend for inverters with low EMC/EMR?
Hi Nutters, Ronald here.
All inverters have to meet Australian standards for EMC/EMR. This means they should give off very little. But which ones give off the least, I am afraid I don’t know. EMR can be limited by placing it in a ventilated tin box or behind fine wire mesh, but obviously it would be more convenient if you didn’t have to do that.
One thing that has been known to cause interference with people’s TV signals are solar panels with panel string optimization, such as Maxim optimization:
https://www.solarquotes.com.au/blog/maxim-just-killed-microinverter-dc-optimiser/
So you may want to avoid them.
Our inverter is on a timber wall back to back with our nbn equipment, the inverter intanet connection which we havent used takes over our ipads and laptop we have selected forget this but it still seems to come up like our provider to the point i had to turn the inverter off to actually get on line
I wrote above on 18 August. Since then, after testing TV signal strength all over our roof, TV technician ascertained that the interference with our signal was coming NOT from the inverter/s (we have two side by side), but from the panels themselves (Canadian Solar – optimised versions) – perhaps reflecting the signal? Solution was a new digital antenna located on leading edge of gable away from the panels, with new cabling to internal TV points. Result is clear picture during daylight hours!
Hi Finn,
Very interesting article and may have answered an issue we are facing.
I have a few lights which are controlled via microwave motion sensors. These are mounted on the ceiling, above which there is a fairly large solar system (I can find out about the system capacity if necessary). The lights/sensors behave erratically. The sensors keep triggering the lights randomly even when there is no one in the space. There are no problems with the lights or sensors, which we checked numerous times.
Would the high frequency noise from the inverters confuse the microwave sensors into thinking there is motion? I believe microwave sensors work by transmitting microwaves and checking the phase change in the frequency upon receiving them.
Cheers,
Ash.
Hi Finn
Recently had solar installed with solar edge. Now my TV channels are dropping out when the solar is working. The installer is say it is because of weak TV reception and is sending a TV antenna guy to check this out. Still waiting. Sounds like the problem is out there with solar. Maybe your team can find an answer.
Hi Michael, Ronald here.
I found this from SolarEdge on radio interference:
https://www.solaredge.com/sites/default/files/feed-in_limitation_application_note.pdf
They suggest:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and the receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help
Their fourth point — consult the dealer — should be the first step here in Australia. Under Australian Consumer Law, our Consumer Guarantees say products must:
– Be safe, lasting, with no faults
– Do all the things someone would normally expect them to do.
Clearly, one would not expect a solar system to interfere with TV reception and they should relocate or replace your antenna or do what ever else is required to remedy to problem.
Hi Finn or Ronald
I have a TV and an NBN satellite dish on my garage roof with coax cables travelling about 15 metres to the house.
I am about to install 10 LG 335W panels (with 10 SolarEdge Optimisers) on the garage roof.
Subsequently the DC cables will run back to the house for about 15 metres before connecting to a SolarEdge HD Wave inverter.
At one point, during this panel to inverter connection, the DC cables will run side-by-side with the existing coax cables for about 4 metres.
Will this particular 4 metres of parallel cable and proximity situation cause EMI problems?
Thanks (as always)
Paul
Hello Paul, Ronald here.
DC cables should definitely not cause EMI problems. DC current produces stationary standing waves so there should be no real possibility of interference.
But I will warn you that some people have experienced TV and radio reception problems after installing optimizers. Generally this is only an issue when the signal being tuned into is weak. I would assume your NBN dish will be fine, but it’s not something I’ve had experience with.
My neigbours installed solar micro inverter panels a few years ago I had trouble with channel 2 and SBS so called TV repair man He changed aerial and booster then told me my neighbour had a faulty inverter but they tell me they have micro ones As soon as the sun hits the panels the pictures break up. is this normal?
My 3k inverter creates noise interference (RFI?) across FM and AM radio stations when switched on. Am assuming the DC to AC conversion is the culprit? How do I fix this, even though the radio is DC powered off the same battery bank that feeds the inverter (and doesn’t power the radio)? Cheers
Hello,
I am about to purchase a new solar power system for my house. I was thinking of getting an Enphase micro inverter which converts DC to AC on the roof. I heard that this results in a lot more electro magnetic radiation all over the roof as opposed to a string inverter where it is all in the inverter box on the side of the house. I really don’t want this EMR surrounding me 24/7, Is this true about the Enphase micro inverter? The solaredge inverter with optimiser might be a good alternative but I read many comments about how it can affect TV signals. I have an antenna near my house and a Foxtel satellite dish. Maybe I should stick with a string inverter like Fronius or SMA. I really don’t have any major shading issues. Any thoughts?
.Hi Finn
Does grounding solar panels help with RFI? I’m a ham operator and have solar panels and my HF radio has S9 on all frequencys. Thank you
Hi,
I installed my robotmower who uses RF bounding wire around the garden, but I noticed a very strange problem, it can not detect the signal in a large section of my garden in daytime, but at evening, starting around 20u30pm (around sunset) it always works perfectly!
Could mine or my neigbours solar panels on the roof be the problem (RF interference)? My neighbours panels are visible in the part of my garden where the problem is. My solarpanels are not visible and shut down around 21u20.. ? Or could it be my neighbour radioamateur installation on the roof? I am the only one with a robot mower so its not interference with another mower.. The loop signal light on the base station is Ok.. very frustrating..
I also tried the method with a AM radio and noticed more noise where the mower can’t pic up the boundarywire signal.. Do you know how to solve my problem? Thx!
I recently had a 10Kw SolarEdge inverter with 34 SolarEdge panels. SInce install I generally lose TV reception for all channels bar ABC. I’ve had and aerial technician come out to check the antennae and it’s fine (we get TV fine on cloudy days and evenings), but he did replace wiring and installed conduit as it appeared cockatoos had gone to town. The solar installers believe the optimisers are the problem, but I’m not convinced. The antennae chap has been back to discuss with the solar ‘technician’ and they don’t agree. The only time the interference goes away is when the inverter is not running. I cannot see how it can be the optimisers as the interference is worst right above the inverter and lessens as you get further away from it. If it were the optimisers the issue would be consistent across the whole roof as the whole roof is covered with panels and optimisers. And I would have thought that switching off the inverter in the middle of the day would not affect the optimisers as they are still on the panels which are still receiving sun light. I get photosynthesis and how plants generate sugars from nutrients and sunlight, so not a complete dummy here, but this solar stuff seems to be a little beyond my brain power, or the solar ‘technician’ is trying to get out of this on the cheap by paying for a longer aerial pole…
“The school is out on exactly what harm can occur ”
Make that read:
“The jury is out …”
Juries determine guilt or otherwise, not schools.
The FCC has rules about interference, and most non-radio devices fall under Part 15, it must accept any interference it receives, and it must not cause any interference. While most situations there is no issue, as commercial FM, AM, and TV stations run thousands of watts and you receive the signal on equipment that is not very sensitive since the transmitters are so powerful, but if you have a ham radio operator or short wave listener in the area with extremely sensitive receiving equipment, you may be causing him grief that he has a legal right to make you fix. It would be better to have the installer certify the system as RFI generating free, (and have the credentials to prove he knows what he is doing in this area) and prove it with data from a spectrum analyzer that can be used in the future to determine system degradation as an RFI source, or court and lawyers will be in your future.