HFU HF Underground
General Category => General Radio Discussion => Topic started by: flexoman61 on May 09, 2016, 1501 UTC
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My next door neighbor has a crew installing solar panels on his roof.
I wonder what to expect for QRM from that mess?
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Nothing from the panels themselves, but the associated charge controllers (esp if PWM) for the batteries and inverters etc can and are likely to cause significant amounts of noise. Steps can be taken to reduce the noise but when it's not your installation --- good luck!
73 Don
with 6 kw of installed solar power visible in <iframe width="560" height="315" src="https://www.youtube.com/embed/IBChwkjzliw" frameborder="0" allowfullscreen></iframe>
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Please let us know what happens to your local noise level after they get switched on.
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Will do Chris. Maybe I will only have noise during daylight. The inverters ect. should only be operating during daylight, I hope.
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Flexoman61, you may want to PM Skipmuck, he speaks about having this problem a lot on chat.
JC
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Most likely you will only have switching trash during the day, as that's when the charge controller is doing its job. Both PWM and MPPT type controllers use switching techniques to regulate charge current and usually are not well filtered. At night, unless its an off grid system with AC output, things should be pretty quiet.
Good Luck!
+-RH
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I've had serious problems with the neighborhood solar power installations over the last couple years. When the first one was put up on my next door neighbors house, the QRN was so bad I almost gave up listening to shortwave. After some deliberation I chose to make several phone calls to the solar power company (Vivint), as well as the makers of the Enphase Envoy system that monitors the system. I basically got the brush off...."Oh, you're a Ham operator?", which I am not. I pointed out to them in follow up calls that their system was not compliant with Part 15, and also that the RFI was very likely propagating as far as the nearby military base. I did notice that after a few weeks, the QRN would terminate abruptly a short time after sunset. From what I can determine from extensive research on the internet, is that some solar power installations are quiet and others are spewers of RFI noise. The main culprits are the cheap Chinese microinverters used in some of the installations and the Pulse Width Modulation charge controllers. Vivint solar apparently uses these in their Enphase Envoy system. The Envoy System can be plugged into any AC outlet and it monitors each microinverter's performance, sending this information to the "Enlighten" Website using a broadband connection. The data is collected by the Enphase Envoy over the existing powerline. What happens here is that the whole house becomes basically a large emitter of RFI. It is a loud buzzing sound on large swaths of the HF band. I've used a portable to do some DFing and anything metal on my house seems to pick up this RFI and reradiate it. It can easily reach S8 on my NRD-515. Lately it's been shutting down at a few minutes after 0000 UTC or so. There are many remedies for this...here are a few links that have been sent my way...I hope you don't need them!
http://mikestechblog.com/ubuntu-antenna/solar-panel-installation-on-the-roof-of-my-home/2/
http://www.solar-electric.com/reducing-electromagnetic-interference-pv-systems.html/
http://palomar-engineers.com/rfi-kits/solar-system-rfi
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Thanks skipmuck, I was hoping you would post. I've seen you complain about your neigbors solar panels in your posts. I'll see how it goes when they fire it up.
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Well, I'm not hearing any fallout from my next
door neighbors solar panel set up, day or night. I guess I'm
a lucky SOB!
I will have to cancel my midnight covert
operation I had planned. I was looking forward to
that.
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I have had solar panels for the past three years and have not noticed any difference in reception - I have used 40 feet of wire for an antenna for over a decade. My panels are about 20 feet above my radios (on the first floor) and 15 feet above the long wire. The solar control panel is in the basement on the opposite end of the house. I have far more problems with a lap top near a radio than the solar panels but I guess the type/installer may play a factor.