Solar Panels and TV aerials and RF interference?

st999

I am thinking of installing solar panels on my roof but I have been told that my TV aerial, which is in the loft, would no longer work because the solar panels would shield it and I would have to re-locate it on the roof.


Is this correct?


I have also been told that the solar panel's invertor generates a lot of RF interference in the frequencies used by DAB radio.


Again, is this correct?

UncleZen

I would expect an aerial in a loft to have significantly reduced reception if the roof was covered in glass, metal and scilicon. TBH the best place for an aerial is outside on the chimney stack if you have one you'll get a much better reception.

As for the dab question, sorry don't know.

patman99

You will need to relocate the aerial. As TV is now digital, every object that the digital signal has to pass through will reduce it's strength by 20% (this was not so much of an issue with analuoge signals.

I would guess that the issue with rf interference from the inverter may well be cured by having the inverter fitted into 'Faraday cage'. this will shield the outside world from the interference.

kwikbreaks

Will the panels be fitted on the same side of the roof as the antenna faces?. They only go on one side and that may not be the way the antenna is facing - if they are side on to or behind the reflector (the elements(s) behind the one the coax connects to) they'll have no ill effect - ie you have at least a 3 out of 4 and probably more chance that there will be no problem.

RF noise? I dont know but DAB is at a fairly high frequency to suffer from that sort of noise. I do know that there are complaints that HF (short wave) can suffer - todays RSGB (radio amateur) news who are doing some investigations on this -

The RSGB is trying to build a clearer picture of the circumstances in which photovoltaic solar panel installations cause a significant rise in the noise levels on the amateur bands. If you, or a neighbour, have installed Solar PV, please let us know whether you have noticed an increase in noise level. It is also valuable to know if noise levels are unchanged. The RSGB website has details of the information the Society would like to know, which includes things like power rating, equipment make, model and date of installations.

http://rsgb.org/main/technical/emc/solar-pv-panels/

neilwoods

As said, all depends on where the Tv mast is, if it north facing then should be as the panels will be fitted on south facing.

As for interference, more likely to do with the cabling between the panel and inverter, after all most will use figure of eight cable with no shielding. Decent full shielded cable would stop the interference. Only logical place it would cause RF, as the panel and inverter would have to comply with certain safety protocols.

Heafalump

I have just had solar panels installed and found that my BBC and some of the obscure programmes now has no signal and had an aerial in the loft. ITV and Channel 4 (I guess a different transmitter) is ok. Tried moving the aerial around in the loft to no avail (was hoping that if the aerial was above he level of the panels it might be ok.). Panels were on the same side as the transmitter.

Rodders53

patman99 wrote: »

As TV is now digital, every object that the digital signal has to pass through will reduce it's strength by 20% (this was not so much of an issue with analuoge signals.

Wrong. The digital signals are just data encoded on analogue radio waveforms, and the attenuation effects of objects and materials will be the same (at any one broadcast frequency). Analogue TV signals degraded into noise and ghosting often, but DTT will work perfectly until a cliff edge is met when it just falls over... almost certainly at that point analogue would have been unwatchable, too.

NB a 50% RF power reduction is 3dB loss.... a roof (without solar panels) can often be around 10dB loss = 1/10th of the signal i.e. only 10% left... This is why it is better to get aerials outside... (it also moves it away from electrical wiring interference sources).


Solar panels and inverters if properly designed and if properly installed should not cause interference... but then that is two rather big ifs.

grumbler

patman99 wrote: »

...every object that the digital signal has to pass through will reduce it's strength by 20%

Every? Even a plastic sheet? From a metal sheet, even foil of fine mesh, I would expect close to 100%.

Lorian

get a signal meter with some tails and wire directly in to the antenna on a few feet of cable, and you can reposition the antenna whilst constantly checking the signal strength £13 from screwfix, or under a tenner if you shop around.