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Radio Interference.

Radio Interference.

Many SolarEdge systems as installed radiate interference affecting shortwave radio reception and licensed amateur radio operations. What make this worse is that in an emergency when the grid goes down and the inverter shuts down the optimizers still generate radio noise because they are still powered by the panels. Without power many communication system cease to function. With radio interference from the optimizers emergency communications provide by amateur radio can be severely degraded. This happens only between dawn and twilight, but disasters can happen at any time. FCC and ARRL are aware. I hope that FEMA is aware also. At present I"m unaware of any interference to aeronautics.

Passion2Fly | 15/01/2020

power optimizers are usually shielded in metallic enclosures and should have very little noise. did you check the datasheet of a power optimizer to see? solar edge optimizers comply with FCC Part15 Class B, IEC61000-6-2, IEC61000-6-3... this is not good enough?

rickwise | 16/01/2020

No, this is not good enough! The installations are done poorly with panels connected in a loop. Panels should be connected so that the series wiring goes from panel to panel to the last panel then back along the same path with the return wire twist with the wire that goes out from panel to panel. This will self shield like a twisted pair cable instead of radiating like a loop antenna. This happens from dawn to twilight. This extends from before sunrise to after sunset. In dim lighting conditions the optimizers are energized. They get up a little before sunrise and stay up a little passed sunset. About 20 minutes after sunset.

Passion2Fly | 16/01/2020

Aha, very interesting!

I know that aeronautical frequencies are between 100 MHz - 400 MHz. Also FEMA seems to use the 400 MHz band:
https://www.radioreference.com/apps/db/?aid=7770

Now, the power optimizers are DC-to-DC converters with switching frequencies up to 10 MHz.... I don't see that interfering with FEMA... However, amateur radio operators might be impacted if operating below 10 MHz...

rickwise | 16/01/2020

Theoretical square waves consist of an infinite number of odd harmonics. Using 10 MHz as an example odd harmonics would be 30, 50, 70, 90, 110, 130 and so on. Amplitude varies inversely with the harmonic number and power by the square of amplitude of the harmonic. For example the 9th harmonic amplitude is 1/9 of the fundamental. the power would be the square of that or 1/81 of the fundamental power which is still greater than 1%.
Switch signal are probably rectangular and not square so harmonic content is different. These are only approximations.

rickwise | 16/01/2020

By the way amateur radio is used in emergencies by
FEMA, and VOAD organizations use such as
Adventist Community Services
All Hands Volunteers
American Baptist Men
American Radio Relay League
American Red Cross
Brethren Disaster Ministries
Catholic Charities, USA
Christian Disaster Response International
Christian Reformed World Relief Committee
Church World Service
Church of Scientology Disaster Response (also known as Volunteer Ministers)
City Team Ministries
Convoy of Hope
Episcopal Relief and Development
Feeding America (Formerly America's Second Harvest)
Feed the Children
Habitat for Humanity International
Headwaters Relief Organization
Hope Coalition America
The Humane Society of the United States
International Aid
International Critical Incident Stress Foundation
International Organization for Victim Assistance
International Relief and Development
International Relief Friendship Foundation
Jewish Federations of North America
Latter-Day Saint Charities[6]
Lutheran Disaster Response
Mennonite Disaster Service
Mercy Medical Airlift/Angel Flight America
National Association of Jewish Chaplains
National Organization for Victim Assistance
Nazarene Disaster Response
Noah's Wish - Animal Disaster Response
Operation Blessing
Presbyterian Disaster Assistance
REACT International
The Salvation Army
Samaritan’s Purse
Save the Children
Society of St. Vincent de Paul
Southern Baptist Convention –North American Mission Board
Taiwan Buddhist Tzu Chi Foundation USA
United Church of Christ –Wider Church Ministries
United Methodist Committee on Relief (UMCOR)
United Way of America
Volunteers of America
World Vision