[RFI] ELECTROMAGNATIC INTERFERENCE from SOLAR VOLTAIC ARRAYS

[David Eckhardt]

The subject leaflet made its way to my inbox via the UK.  It was requested
by a member of the Radio Society of Great Britain and members of that
organization.  On reading the leaflet they became concerned with your
leaflet accuracies and assumptions.  I've read it and agree with their
assessments.  In many cases, it is blatantly in error.

The leaflet can be accessed at:

          https://www.nrel.gov/docs/fy17osti/67440.pdf

I am retired after some 40-years as an EMC/RFI engineer
(HP/Agilent/Keysite, StorageTek, Phillips Lab, and a number of smaller
consumer companies) with a degree in physics.  I still do a bit of
consulting in the discipline and have a relatively functional RF lab.

I would strongly suggest someone in your organization who is highly
familiar with EMC/RFI (not the authors) read the leaflet for technical
accuracy.  Subjects to keep in mind might be frequency domain signatures of
high-speed digital and power switching, source isolation, shielding (don't
malign the Faraday Cage), proper cabling treatment and installation, use
and proper installation of appropriate ferrite material, basic EM theory,
high-power filtering, basic antenna theory, in-circuit E and B-field
coupling, and other associated subjects.  Also consult the publications
offered by ARRL in this respect.  In addition, consult the RFI division of
ARRL for real-life experiences involving severe RFI caused by solar voltaic
installations.

Once the above is accomplished, I believe a serious re-write of the leaflet
will be in order.  Many of the assumptions, conclusions, and statements in
the present leaflet are in error.    As it stands, it is an embarrassment
to the reputation of the NREL.

David A. Eckhardt - WØLEV

EMC Design & Test, LLC
RF and Antenna Design