Solar panel mains interference

[jonnybear]

This has probably been mooted before. Pursuing my now hobby of repairing vintage radios, I have noticed the terrific amount of noise coming from the mains, and have pinpointed it to solar panels. During the day it is almost impossible to receive anything on any AM without an overwhelming buzz (this is on mains receivers). During darkness, perfect reception. The other day our neighbour's panels packed up and reception was good again, until repair was carried out. Now we are back to the buzz again, has anyone else had this problem?
John

[trobbins]

Are you saying that a battery powered AM receiver has no problems - just a mains powered AM receiver?

Or are you saying that any AM receiver is having a problem due to noise presumably radiated from AC mains wiring (which is connecting a PV inverter to the grid). If so, then is the noise direction localisable to the PV modules on your neighbours roof, or the AC mains wiring going to the PV inverter?

[julie_m]

The PV modules produce DC. They are wired to a grid-synchronous inverter; which converts the DC from the panels to AC with its crests and troughs lined up perfectly with the mains, so you can actually supply power into the distribution grid. My inverter is installed in the loft, so the DC wiring is as short as possible, but some installations have the inverter close to the consumer unit.

Anyway, there's an easy fix Simply tell the householder in question that if energy is coming out in the form of RF interference, it's not going through their generation meter, and as a consequence their FiT payments will be reduced .....

[jonnybear]

The noise is not so noticeable with a battery powered radio, it does not seem to be directional, it is so loud on L/M bands that speech or music during the day is impossible, at night it is fine.
John

[G8HQP Dave]

The equipment associated with a solar panel can radiate from MF to VHF. I would not be surprised if it puts stuff on the mains too.

The noise floor on national FM is raised here on sunny days. Even worse on local FM stations.

[Hybrid tellies]

Some nearby houses do have solar panels on their south facing roofs but thankfully I don't suffer any interference from them. Do these in errors have filters fitted to the input and output and are they in screened cases?
I an suffering a new type of mains born interference which effects the upper end of the medium wave band night and day. Using a small portable radio I have tracked the noise down to the incoming u/g mains cable, the investigation continues.

[trobbins]

The PV modules are typically connected in series and the dc cell circuit is isolated from earth - they would certainly make a good antenna for mppt switch mode noise. However the pvinverters are all compliant to standards, so I can't see much chance of formally complaining, whether it is radiation from mains cabling, or from the DC external loop.

[mole42uk]

Some solar installations use mains-bourne communications for their monitoring. Others use inexpensive inverters which produce high levels of THD on the outgoing sine wave.
Your interference is unlikely to be associated with the DC wiring unless there's a bad connection somewhere. If the system uses micro-inverters (one per panel) then the associated mains THD might be higher than usual.
Best practise is to run positive and negative cables parallel and close to each other to prevent them becoming a loop antenna, MCS accredited installers should have checked this as a matter of course.

[davidw]

Originally Posted by trobbins

However the pvinverters are all compliant to standards,

May be so in Australia, but not according to UKQRM ..about halfway down the page.

http://www.ukqrm.org.uk/misc.php