Solar panels

[Guest Sean]

I live in the south west corner of Ireland a Paradice for wildcamping. I have two leisure batteries in my hymer 544 but I can only get two nights power as I use a satilite system with inverter. Should I consider a solar pannel and what output would I need.

[Guest Neal]

Sean I have a 110W solar panel sevicing two 110Ah leisure batteries. These are connected to a 800W inverter to power a TV and Sky digibox. The most we've used it without hook-up has been for 5 nights at about 4 hours each night and it hasn't seemed to affect battery capacity at all. I wouldn't feel comfortable without the solar panel. Regards Neal

[Guest Clive]

Plus its all about being economical with the power as well. I hope you are using a LCD TV screen as these take a lot less power that those with a cathode ray tube? Have you tried fitting a reflector behind your solar panel to reflect more light onto the panel? This does mean you should park east / west but it helps and is cheaper than another solar panel! Mine is made of ply wood and covered with aluminium foil.

[Guest Neal]

Clive Two things: Firstly, no, I have a CRT TV video combi which was everso cheap in Tesco 2 years ago. Remember, some of us have to be economical with the "folding" as well as with the power!! Secondly, are you saying that commercially available solar panels are double sided? I readily own up to the fact that I had never considered this possibility. I thought they were constructed so that the photo-voltaic cells faced upwards, towards the sun. I have to say that parking up requires more input than just the sun's position. Don't forget the dish to satelite alignment, not forgetting the sun's aspect on the patio!! I joke not! Regards Neal P.S. The only show we can make this year is Newbury (Southern show). Will you be there? If so, how will we know you? I would like to shake your hand, old chap. Regards Neal

[Guest Clive]

Hi Neal, Ideally a solar panel should face the sun, but this means that it cannot be fitted to the top of a motorhome in a permanent position. i.e. placed on the ground at an angle facing the sun and moved every so often as the sun crosses the sky. But, most of us cannot put up with that so just bolt in on top of the roof. The sun is therefore seldom directly overhead. If you park with the panel nominally laying east - west then the sun is always going to be one side and will travel from one end to the other. As the sun is always to one side you can put a mirror standing near vertical along the back long edge of the solar panel. Any sunlight the shines on the mirror is reflected into the FRONT of the solar panel and will increase its output. But if you park at other angles then you need to move the mirror several times else it will at some time cause a shadow and reduce output from the solar panel. We shall be at Newbury. Parked in the Press area and number plate R4 MOT is a give away, as is a rather tall whip antenna on top. I look forward to "pressing the flesh" as they say.

[Guest Neal]

Thanks Clive, yes I see what you are saying regarding reflection now. I think science would need to be applied in comparing the effort required to reflect light onto a horizontal panel over a given (but variable) time against the increased output from the panel, whilst monitoring the physical energy (and time) saved by doing nothing except chilling/drinking in the warmth of the sun. You will have detected that I am a lazy b*stard! I'll look out for the distinctive plate with the whip antenna. We should be amongst the RV's reading M9 ARV (My ARV?) Regards Neal