Ground plane antenna vs. solar panels - Page 1
Forum section: electronics / rf-microwave

author: 5U4GB
author_rank: Super Contributor
timestamp: July 04, 2025, 07:59:49 am
content: I've got an AIS antenna on the edge of the roof in a location where more solar panels are getting installed, just a monopole and three radials providing the ground plane, one of which runs directly along the roof where the panels need to go. It's not possible to move the antenna, which is part of a substantial mast bolted to the wall, and rotating it won't help because it'll just move a different radial into the way, but it should be possible to raise or lower it by a few cm to move the radial either above or below the panels.What would be the best option for dealing with this? Below the panels would be easier, it'd be out of the way of the installers and in fact may already be in a position to fit under the panels as is, but it might also be possible to raise it so the radial is above the panels. So perhaps an alternative phrasing might be "how badly will performance be affected with the easy option, one radial underneath the panels".

author: Hamelec
author_rank: Regular Contributor
timestamp: July 07, 2025, 10:47:41 am
content: only for receiving? it doesnt matter..The only problem maybe some EMI from inverters

author: 5U4GB
author_rank: Super Contributor
timestamp: July 07, 2025, 12:30:51 pm
content: Thanks! I was hoping that'd be the case, all the discussions of ground plane antennas talk about effects on transmission but this one is receive-only. The frequencies used for AIS are around 160MHz so hopefully there won't be any harmonics going up that high. Weather permitting I'll be putting the panels up tomorrow then.

author: stretchyman
author_rank: Regular Contributor
timestamp: July 07, 2025, 01:21:23 pm
content: Personally I wouldn't put up an antenna (espec) receiving anywhere near anything electrically active.Solar panel usually have very cheap convertors in the system, they have got better but they will still generate a load of noise.Fortunately on VHF it wont be as bad as HF but will be noticeable.Why you'd want to place a radial 'under' the panel god only knows!I'd put the antenna as far away and 20 feet above them personally.J.

author: 5U4GB
author_rank: Super Contributor
timestamp: July 08, 2025, 05:06:43 am
content: I don't have much choice, it's at the highest point of the house with the best view of the section of harbour that it covers. It was also set up to be pretty cyclone-resistant so even if there was somewhere else to move it to it's not just a case of loosening a few screws and relocating it, it would require putting up scaffolding to work on it.

author: stretchyman
author_rank: Regular Contributor
timestamp: July 08, 2025, 06:25:54 am
content: Cyclone resistant, I hear that!Does need to be up and away from those panels tho'.

author: Peabody
author_rank: Super Contributor
timestamp: July 08, 2025, 02:39:02 pm
content: Don't you also need to consider the effect of the antenna's shadow on the panels' performance?

author: 5U4GB
author_rank: Super Contributor
timestamp: July 09, 2025, 05:25:34 am
content: No, it's to the south of the panels so never gets in the way. In addition with modern panels an 8mm rod sticking up won't have much if any effect on production (the plumbing is all down below the level of the panels), there's a Youtube video someone did where they obscured panels in various ways and the loss was negligible. Tried to find it again to post a link but all I got was a mass of conspiracy-theory videos about solar - did you know they're actually secret Chinese spy devices?

author: Peabody
author_rank: Super Contributor
timestamp: July 09, 2025, 02:02:29 pm
content: I was basing my question on Dave's video of his experience:But apparently modern panels, or maybe modern inverters, don't have this problem.And yes they are chinese spy devices, just like 5G.

author: richnormand
author_rank: Unknown
timestamp: July 09, 2025, 11:04:22 pm
content: Depending on a lot of factor, depending of the whip antenna length and size.In my location I would be more worried about lightning strikes on the antenna near the panels and the inverters.

author: Stray Electron
author_rank: Super Contributor
timestamp: July 10, 2025, 12:10:57 am
content: Quote from: richnormand on July 09, 2025, 11:04:22 pmX10. exactly what I was thinking. Lightning is a major problem in many parts of the US and I wouldn't put any kind of antennaanywherenear a solar system. FWIW a friend of mine recently told me that lightning struck his house and that it blew a large hole in his roof and the ceiling below it and started a small fire. But it also arced over to some electrical wiring in the attic and got into the AC electrical system and from there the magnetic field in the electrical wiring actually induced a large current into a nearby copper water pipe that was grounded and blew a hole in the pipe and the resulting water leak flooded his home. He and his wife were home at the time and a neighbor saw the lighting strike and the smoke from the fire and came to their house and told them what happened. The fire was small enough that they easily put it out and what they didn't know what the the pipe had burst inside of an interior wall and they didn't know about it until water started flooding their house. All told it was over $80,000 worth of damage and that was over 20 years ago. This all happened in Kansas which isn't a particularly lightning prone area.If you think that I'm joking about lightning be able to create enough current flow in electrical wiring that it can magnetically induce huge currents in nearby copper pipes then go read the specifications for lightning protection systems by the (US) National Protection Association. I'm not sure of the exact title or the organization but that should be close and Google should be able to find it.

author: 5U4GB
author_rank: Super Contributor
timestamp: July 10, 2025, 02:35:43 am
content: We're towards the bottom of a range of hills (the ones that screen the lower harbour from the upper, which is why my AIS location is useful) with tall trees above and behind us, and it's below the top of the metal roof so I doubt it's much of a target for lighting (that is, it faces out across the harbour with the peak of the roof on the landward side behind it). It's also got a 15m long optoisolator (fibre run) along with everything else that has conductive parts sticking out outdoors, so won't affect the remaining IT gear. A fair bit of planning went into setting it up to be relatively resistant to the elements.