I also have trouble accepting the panel noise theory SolarEdge claims. If
that were true, why is it that some brands of inverters never cause RFI, yet
the same solar panels are used on all solar power systems? This could be
tested by loading a solar panel that is suspected of causing noise and
measuring the level of conducted RF voltage. Then assuming the wiring is
making an efficient antenna, calculate the strength of the radiated signal.
I suspect the result will be below a level that can be detected even a very
short distance away.
From: RFI <email@example.com> On Behalf Of Hare,
Sent: Sunday, August 30, 2020 8:50 AM
To: Tony Brock-Fisher <firstname.lastname@example.org>; Tony <email@example.com>; Rfi
List <firstname.lastname@example.org>; Gruber, Mike W1MG <email@example.com>; Cianciolo,
Paul, W1VLF <firstname.lastname@example.org>
Subject: Re: [RFI] Covering Solar Panels To Assess RFI
This could be misleading. In the unlikely event that the panels themselves
are generating noise, disconnecting them from the optimizers would remove
them from a large length of common-mode radiator. The only noise I could
remotely imagine coming from a panel would be white noise, shaped by
resonances in the wiring doing the radiating. They are diodes, although
ones generating voltage, so they could be diode noise generators. Having
said that, though, the level of noise that comes from a diode designed to
generate noise is very low, so I am having trouble believing that the
panels' diodes could generate noise that would be radiated at a level strong
enough to cause harmful interference. I am willing to be proven wrong, but
my first instincts would be to look elsewhere. And if panels were generating
noise, a simple capacitor across the output wiring should tame it down.
From: Tony Brock-Fisher <email@example.com>
Sent: Sunday, August 30, 2020 8:39 AM
To: Tony <firstname.lastname@example.org>; Rfi List <email@example.com>; Hare, Ed W1RFI
<firstname.lastname@example.org>; Gruber, Mike W1MG <email@example.com>; Cianciolo, Paul,
Subject: Re: Covering Solar Panels To Assess RFI
The obvious test would be to disconnect the optimizers from one or more
panels, expose them to sunlight, but cover all the rest. This configuration
should be quiet.
On 8/29/2020 7:31 PM, Tony wrote:
> On 8/26/2020 6:53 AM, Tony Brock-Fisher wrote:
>> It is highly unlikely the panels themselves generate RFI without the
> I agree with you Tony.
> When we informed SolarEdge about the noise disappearing when we
> covered the panels, they came to the conclusion that solar panels
> themselves were at fault.
> The fact is that the entire system shut down when we covered the
> panels so how they can blame the panels and discount the inverter and
> optimizers is beyond me.
> We know what the inverter noise looks like because all we have to do
> to make it appear and disappear is turn it on and off.
> The optmizers get their power from the solar panels so we had to cover
> the panels to stop the RFI they emit. As you know, there's no switch
> to turn them off.
> Thanks to my neighbor, I have unrestricted access to the system so
> I've been able to perform these tests dozens of times. I'm hoping
> SolarEdge will come out and do the same.
> Tony -K2MO
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