Was this experiment conducted with the per-panel optimizers connected to
the panels? This is a critical question.
It appears the conclusion of the experiment is that the panels
themselves and by themselves are generating RFI. I am certain this is
incorrect. I suspect the experiment was conducted with the optimizers
connected to the panels, and that the panels powered up the optimizers
and the optimizers are generating the RFI, which would be entirely
consistent with my understanding and experimentation with a single panel
and optimizer. Indeed, a 300W halogen lamp provides sufficient energy to
a single panel to power up an optimizer such that it generates RFI, the
characteristic being harmonics appearing at ~200kHz intervals through
20m and above.
It is highly unlikely the panels themselves generate RFI without the
optimizers, unless they contain some sort of active circuitry that
operates at RF frequencies. Electrically, they look like a huge diode
which is back-biased by the voltage developed in the presence of
sunlight. A solar cell, by itself, does not generate RF.
As is often the case, a poorly conducted or misunderstood experiment can
lead to an erroneous conclusion, which then leads to a futile course of
action yielding a lack of productive results and further frustration.
I hope you can clear up this discrepancy before many more wheels are
On 8/25/2020 8:44 PM, Tony wrote:
The the inverter on my neighbors solar panel installation was recently
replaced to reduce the RFI caused by the system. The swap only made a
slight change in the interference.
This left the solar panels as the possible source of RFI so my
neighbor and I conducted a test we've done previously which involves
covering each panel with tarps to see what affect it would have on the
We found that the RFI completely disappeared while the tarps were
blocking the Sun from reaching the panels. The noise returned when we
removed the tarps.
I reported this to SolarEdge and they now believe that the panels are
the cause of the interference. They mentioned 2 other installations
that had this same problem with panels that were manufactured in China
by Hanwha and Trina.
The takeaway is that solar panel systems need to be checked from top
to bottom when checking the system for interference. I'm hoping
SolarEdge will keep this in mind when they address their next RFI case.
We also reported our test results to the company who leases the panels
to my neighbor. No response yet.
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