[RFI] SOLAR INSTALLATION PROS/CONS

[qrv at kd4e.com]

Perhaps we need to bring this information before city and town councils
and request regulations that protect citizens from RFI?

It sure would not hurt to ask - especially if we demonstrate that said RFI
could interfere with emergency communications and more.

Don't allow the systems to be installed (no permits) unless they meet 
standards.

Prevention rather than remediation?

WDYT?



> Bob,
>
> I developed and taught for 15 years a university-level
> engineering course on renewable energy systems
> design, which was principally devoted to PV systems
> design.  Here are some recommendations if you're
> evaluating PV for your own use - getting neighbors
> to regard the RFI issues with the same degree of
> seriousness is a much stickier wicket.
>
> 1) Sacrifice some overall conversion efficiency by
> using a single central inverter (if your array isn't
> so large as to require paralleled inverters).  Do
> NOT be sold on the use of microinverters (solar optimizers)!
> The microinverters do increase overall system conversion
> efficiency, but at the expense of adding typically
> one microinverter per PV module.  That multiplies
> the RFI by the number of PV modules.  The microinverters
> enable use of smaller wire gages and standard interconnect
> bus voltage (240 VAC) to the array junction box, and that
> was (and even more so now is due to copper prices) a significant
> cost-savings by not requiring custom array designs (number
> of modules per string and number of paralleled strings)
> and heavier interconnect wire gages.
>
> 2) A single central inverter has MPPT (maximum power point
> tracking), which is also the principal selling point for
> the microinverters (each of which has MPPT to
> extract maximum power from its PV module under
> variable illumination and partial shading conditions).
> The central inverter designs sacrifice some overall
> efficiency because they can only compensate for
> array-scale variability of the composite I-V curve
> over temperature and solar irradiance, especially
> non-uniform shading of the PV array.
> A competent PV system designer will generate a
> detailed site shading analysis for the array and will
> qualify the design's power output over the course
> of a year, then adjust the array design to ensure
> the customer's needs are met.
>
> 3) Insist that the inverter selected by the installer
> meet FCC Part 15, Class B radiated emission standards.
> Go further and insist that the inverter meet
> conducted RFI limits on both the DC and AC
> sides.
> Dave, W0LEV, is correct in that the FCC does not
> specifically regulate PV system RFI emissions.
> However, emissions from unintentional RF radiators
> (e.g. switch-mode DC-DC or DC-AC converters) ARE
> subject to FCC limits, and may be subject to FCC Part 18
> limits as well.  I have read several web sources that
> suggest that PV systems are exempt from FCC RFI
> regulations, and this is NOT true.  The PV modules
> generate DC, but the module and array interconnect
> wiring makes wonderful antennas for the switch-mode
> power converter signals if these are not filtered
> adequately for both differential- and common-mode
> signals at the switching frequency and its harmonics
> (up to the 10th harmonic or so).
>
> 4) Ask your installer for references to other installations
> done nearby within the past 2-3 years.  Take a portable
> shortwave receiver and visit the sites during the
> day and again at night.  Be sure that the installation does
> not have a battery storage unit - the central inverter or the
> battery unit itself (with self-contained inverter) will
> continue to generate RFI at night using the stored battery
> energy.
>
> 5) Contact the installer's preferred inverter manufacturer
> and ask if an independent testing lab has measured both
> radiated and conducted RFI.  Ask for those results if
> available, and if not available, choose a different inverter
> manufacturer.  Better yet, ask the manufacturer to hire
> K9YC as a design consultant!
>
> 73,
> Mike, K8CN
>
>
>
> ________________________________
> From: RFI <rfi-bounces+mike.carter=unh.edu at contesting.com> on behalf of Robert T. Devine <rtdevine at comcast.net>
> Sent: Sunday, May 23, 2021 3:32 PM
> To: rfi at contesting.com <rfi at contesting.com>
> Subject: [RFI] SOLAR INSTALLATION PROS/CONS
>
> Caution - External Email
>
>
>
>
> Looking for information from those that have experienced Solar Installations
>
>
>
> Pro's and con's appreciated
>
>
>
> Thanks
>
>
>
> Robert T. Devine, KC6AWX
>
> Manager, ARRL 6th District Incoming QSL Bureau
>
>
>
> "Save a Life...Become an Organ Donor"
>
> 'Be kinder than necessary, for everyone you
>
> meet is fighting some kind of battle.'
>
>
>
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