Mitigating RFI from solar panels

JJ4SDR
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Location: TEXAS, USA

Mitigating RFI from solar panels

Postby JJ4SDR » Tue May 24, 2022 2:40 pm

Hi,

This may be somewhat academic at this point, but I will want to be prepared if feasible and perhaps this question doesn't belong here at all, but with all the effective interference fighting algorithms of the ANAN radios I am hoping that I will be able to still operate my station after the install at a neighbor's property.

Neighbor of mine will likely have a solar power system installed in the coming weeks. Their house is diagonally across the street from our house and approximately 100 feet away.

Now, I exchanged some thoughts long time ago with a fellow (his article on ham radio and solar power co-existence was published in QST some time ago) who has a solar power system and it plays fairly nice with ham radio. Some systems that feature a slew of "micro-inverters" appear to be more "compatible" with ham radio than those that have one or 2 really large inverters.

I would appreciate comments from those who have first-hand experience on this.

Best!
Juha
NI2M
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Ron Stockton
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Joined: Sun Jun 27, 2021 9:24 pm

Re: Mitigating RFI from solar panels

Postby Ron Stockton » Tue May 24, 2022 6:48 pm

Juha,

We have dealt with this issue for years in SoCal. I can tell you that the DC-to-DC converters on Solar-Edge panels from Israel are the worst offenders. These emit crud every 200 KHz. If you hear noise between 14.197 - 14.200, it is a Solar Edge product. Fortunately there is a rep in CA that works with the contractor/installer to add ferrite beads and shielding to mitigate the problem.

Like you said there is a wide variety of panels with micro-inverters and some emit more RFI/EMI than others. You must locate the offending PV system and work with the owner/installer to correct the problem. We found that giving the owner the attached article from the Wall Street Journal is a motivator to "clean-up" their system. In the past the FCC has written letters to owners encouraging them to eliminate the RFI, but recently the FCC has refused to get involved at any level. If indeed you will be dealing with a system 100 ft away and cannot influence the choice of system hardware, you may have a difficult time mitigating a noise issue.

BTW - Some single inverters, such as Sunny Boy products made by SMA , do NOT emit any RFI/EMI. I have had these installed at my home for several years with no noise issues on any band.

Ron N0RR
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JJ4SDR
Posts: 436
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Mitigating RFI from solar panels

Postby JJ4SDR » Tue May 24, 2022 10:03 pm

Hi Ron!
Sure value your feedback based on real-life experience.
Now, I can't be sure, but I believe that the neighbor is contemplating a system by Sun Run (I am basing this on the fact that a car with Sun Run logo was on it). In 2017 Sun Run and Solar Edge had "teamed up," but today I read that Enphase (in CA) would provide micro-inverters so I am a bit confused.
What makes matters slightly sticky is that our community does not allow outdoor antennas of any kind whether visible from the street or not. That said, if indeed there were to be EMI/RFI then I would be broadcasting - pun intended - the presence of a ham radio station and that might end up laying myself open to problems. The neighbor will say that I am not supposed to have a station (or outdoor antennas) in the first place. I have great neighbors (this isn't the neighbor across the street) fortunately. The very last 6 feet or so of my fiberglass pole juts out over the canopy of trees in my back-yard and I think it is visible from the property where the solar power system will be going up. Still, let's just say that if the EMI/RFI is really serious then an indoor antenna would also pick that up in which case I would be "compliant."
You mentioned interference on a narrow part within the 20 m band, but depending on the solar system, other bands will be impacted I would imagine too since you mentioned "crud every 200kHz."
Thank you for sending that WSJ article :) .
Best!
Juha
NI2M
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
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Ron Stockton
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Re: Mitigating RFI from solar panels

Postby Ron Stockton » Wed May 25, 2022 10:31 pm

Juha,

Everything you need to know about Solar Edge RFI is in a May 2019 QST article by KQ6RF, a San Diego local. See attached reference.
I believe Enphase micro-inverters are RFI free. I'll check with my peers and report back next week.
Cheers,
N0RR
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JJ4SDR
Posts: 436
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Mitigating RFI from solar panels

Postby JJ4SDR » Fri May 27, 2022 6:42 pm

Hi Ron,

I appreciate your response and the flag on the QST piece!

While the EMI/RFI caused by many solar systems is probably "too much" even for these fine ANAN radios I would be curious to learn from any of you who have had interference and whether the NB/NR algorithms were able to mitigate the inference at all?

Best 73 de Juha
NI2M
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.4.3 x64
Protocol 2 v2.1.18

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