Why does my garage door opener not work when the sun shines on my solar panels?

[RogerFarmer]

Here's a problem with my solar panels that I have never seen discussed elsewhere. I installed 16 solar panels on our garage roof some years ago. Last year, I added 8 more. The solar panels themselves work great.

The problem is that our remote garage door opener does NOT work well when the sun is shining brightly. This problem began about the time of the original solar panel installation. When the sun is shining brightly then our car has to be directly in front of the garage before the remote opener will work. At night, or on a cloudy/overcast day, the garage door opener works half a block down the street. This is very consistent and happens every time.

The solar panels use Enphase M215 microinverters which use Power Line Communication. According to Enphase specifications, these microinverters use a 144 kHZ communication frequency. The remote garage door opener has a frequency of either 315 and 390 MHz, (effective from 2011), about twice as much. The garage door opener itself uses a household AC circuit plugged into the same breaker box as the solar panel microinverters.

I am wondering if a harmonic of the frequency of the solar panel Power Line communication interferes with the
remote garage door opener. I'm not sure how to test this possibility, but am wondering if this problem has been encountered elsewhere.

I would appreciate any comments about how to analyze this problem and what to do about it. Thanks in advance for any suggestions.

[Ampster]

I agree that RF from the micro inverters is most likely causing the interference. There are some more expensive receivers that have a coax connection so that an external antenna can be mounted. I have heard some radio amateurs say that antenna placement is more an art than a science so you may have to experiment with it.

[Mike90250]

Your theory is about exactly what I was thinking. EMI from poorly shielded or designed inverters has pretty much wiped out usage of lower frequency AM bands including long distance AM radio and HAM radio. The hash they generate can be conducted along power lines and coupled thru transformers. But at night reception improves.
But it's not the powerline comms, it's the switching freq in the inverters that does this with appreciable power radiation a frequencies hard to block.
Low frequency inverters with big iron torroids dont have this issue and I don't understand why the FCC allows HF transformerless inverters to exist.

[sdold]

I've also heard that replacing an incandescent bulb with an LED bulb in the garage door opener can interfere with its receiver. Just mentioning that in case you've done that too.

[Ampster]

I've also heard that replacing an incandescent bulb with an LED bulb in the garage door opener can interfere with its receiver. Just mentioning that in case you've done that too.

Somewhat related, I replaced the tailight bulbs with LED bulbs in a car and the tire pressure sensors stopped working.

[SunEagle]

Somewhat related, I replaced the tailight bulbs with LED bulbs in a car and the tire pressure sensors stopped working.

Of topic. My wife complained that the lights dimmed when she flushed the toilet but I reminded her we had a well pump and she laugh.

The sad part is that some of the foreign electronics that generate RF do not really have FCC approval or shielding so they can interfere with other wireless electronics. I am not sure how to protect against RF because it is being generated across a lot of frequencies.

[J.P.M.]

Of topic. My wife complained that the lights dimmed when she flushed the toilet but I reminded her we had a well pump and she laugh.

The sad part is that some of the foreign electronics that generate RF do not really have FCC approval or shielding so they can interfere with other wireless electronics. I am not sure how to protect against RF because it is being generated across a lot of frequencies.

The house I owned in Albuquerque had a few quirks. 1X/a while the phone (a land line) would ring when someone rang the door bell, but that was NM.

[SunEagle]

The house I owned in Albuquerque had a few quirks. 1X/a while the phone (a land line) would ring when someone rang the door bell, but that was NM.

I use to live next to a HAM operator that would wipe out my TV signal when he transmitted. That was back when TV was broadcast over the air.

It looks like while some of the RF issues have gone away but others are starting to come back. It can be a real mystery to solve.

[bcroe]

Pretty much right so far, but your (and my) 390 MHZ door radios are not twice the frequency,
more like several orders of magnitude greater. The issue most likely is radiation from the DC
to AC inverter, the radiation will increase with the array power increasing in strong sun.

The basic problem is that the crude modulated oscillator transmitter is barely accurate enough
to stay inside the FCC allowed channel, quite a lot of KHZ of bandpass. The receiver must be
at least as broad, no superhets here. So it picks up a lot of noise over that bandwidth, including
switching noise from inverters. A communications receiver very accurately limits the bandwidth
(and the noise received) by very many orders of magnitude, to just what is required to handle
the information. The transmitter of course must have accuracy and stability to stay on that
frequency. In one case I solved the issue by using modified communication equipment.

There are a lot of approaches, one advantage of a string inverter is ability to. shield it to limit
and filter radiation. Not practical with many micro inverters outside in a wide area. Next is go
over the radio link. The simplest fix for me has been to use a modest gain, directional antenna,
which is located as far from the inverter(s) and as near to the remote transmitter as practical.
The receiver is close to, or even built into the antenna. A Yagi can work, some 7 feet long
at 390MHZ, my 11 element design came off the internet. An EAGLE ASPEN Dtv2Buhf Directv
2-Bay Uhf Antenna at the receiver might give you enough front to back ratio to solve the problem.
I might lengthen the elements enough to bring down the minimum freq from 470 MHZ to 315 MHZ
Here a collinear ant gets directivity mounted 1/4 wave from a metal building, which also shields it.

Bruce Roe K9MQG since 1958

2BayAnt.png

[solardreamer]

Here's a problem with my solar panels that I have never seen discussed elsewhere. I installed 16 solar panels on our garage roof some years ago. Last year, I added 8 more. The solar panels themselves work great.

The problem is that our remote garage door opener does NOT work well when the sun is shining brightly. This problem began about the time of the original solar panel installation. When the sun is shining brightly then our car has to be directly in front of the garage before the remote opener will work. At night, or on a cloudy/overcast day, the garage door opener works half a block down the street. This is very consistent and happens every time.

The solar panels use Enphase M215 microinverters which use Power Line Communication. According to Enphase specifications, these microinverters use a 144 kHZ communication frequency. The remote garage door opener has a frequency of either 315 and 390 MHz, (effective from 2011), about twice as much. The garage door opener itself uses a household AC circuit plugged into the same breaker box as the solar panel microinverters.

I am wondering if a harmonic of the frequency of the solar panel Power Line communication interferes with the
remote garage door opener. I'm not sure how to test this possibility, but am wondering if this problem has been encountered elsewhere.

I would appreciate any comments about how to analyze this problem and what to do about it. Thanks in advance for any suggestions.

It's unlikely due to the inverter PLC and more likely due to radiated and/or conducted EMI from the inverter switching frequency (likely in the 20-30KHz range) harmonic noise. The noise could be interfering with the garage remote control wireless signal and/or the garage remote control receiver electronics plugged in to the AC socket. You should probably first determine if it's mainly radiated or conducted interference then consider appropriate fixes such as ferrite clips, shielding, antenna etc.

[RogerFarmer]

Thanks to everybody for your comments. I think I understand that the RFI is most likely radiated from the DC/AC micro inverter mounted on each panel rather than through the Power Line Communication transmitters. Is that correct? If so, it also seems like it's not easy to solve. Thanks to bcroe for a more extensive description of a possible solution. Since this is just a garage door opener, I was hoping for some simple solution rather than an external antenna of some sort. I'm also pretty sure that I don't have the expertise to design/install an antenna system. I did try putting aluminum foil on the ceiling of the garage to shield the garage door receiver, but that didn't seem to have any effect. The solar panels and microinverters are unfortunately located on the garage roof just a couple of feet above the garage door opener/receiver so they are quite close together. I also considered trying to find a UPS to power the garage door opener hopefully independently of the house electrical system to try to avoid the power line communication, but I finally decided that wouldn't work very well and wouldn't really be effective anyway if the RFI is being radiated directly by the microinverters. So I guess I'm back to square one and the only realistic possibility is some sort of antenna system. Thanks again for your comments and any additional ideas.

[sdold]

I should have read your original post better, you were very clear that the problem only happens when the sun is bright and that rules out an LED light. I have the same inverters, if we get some sun this weekend I'll take my spectrum analyzer up on the roof and see if they radiate much on 315/390 MHz.

One thing that might work is to install a different receiver with a different remote control somewhere else, like near the button you push to open the door from inside the garage. I think Genie makes one, designed as a retrofit for older systems. It would let you re-locate the receiver away from the interference.

[sdold]

This one seems like it would work. It basically connects in parallel with the wall button and although they show it being installed on the ceiling near the opener, I don't see why it couldn't go on the wall somewhere away from the solar array.

https://store.geniecompany.com/products/universal-garage-door-opener-remote-upgrade-conversion-kit