Solar panel power

[747]

Hello yeoman,

 

You have certainly come to the right place for old, noisy and smelly objects.

 

Myself not included you understand. ;-)

[Yeoman]

Goodness me!

Well at least you're not tearing into me for suggesting a generator as a more useful bit of kit than a solar panel!

 

There is an opening here for someone to invent and market a really effective baffle box to contain the sound from generators! (If they haven't already - I must say I have not researched this yet). :-)

[Brian Kirby]

Yeoman - 2010-07-23 2:08 PM You say "quiet, means of achieving the same end, are available, and so, inconsiderate and selfish." However, it is NOT achieving the same end is it? You have said that the generator can run anything and 'liven' the sockets in the van. Somewhat different from merely charging the batteries. Surely by now they have invented quiet generators or baffle boxes to put them in? Haven't they just got a bad name by people using ancient noisy and smelly ones?

Apologies for not making myself clear.  A mains hook-up is quiet and achieves the same end.  An inverter will run 230V equipment from the batteries, the limitation being the size of battery bank and the capacity of the inverter.  Solar panels can subsequently re-charge the batteries quietly.  An EFOY (or alternative fuel cell) will quietly generate 12V power on demand, to re-charge the batteries, after running the inverter.

If seeking peace and quiet, and respecting the rights of others to same, do not use generators at times, or in locations, when they may be audible to others.  If completely isolated, to the extent no-one with acute hearing is within earshot, run a genny by all means, or run it in a noisy location or at a noisy time, where it's noise is below ambient.

I'm not anti-generator, just anti-unnecessary noise.  :-)

[thebishbus]

Hi again Brian. Whenever a subject like this comes up you always get the waffle's with all the in's and out's and pro's about it. Just forget all of that, and think. Do you want to be virtually independent of hook up's, or not have to drive around every other day to charge the batteries, if that is the case, for the peace of mind alone, fit the largest/most efficent panel you can. (lol)

Brian B.

[747]

As regards the development of baffle boxes or enclosures. Before I retired, I occasionally came across enclosures to deaden the noise from equipment such as Steam Turbines, Multi-stage Gas Compressors and the like.

 

The basic problem with all of them was the weight of the enclosures. I suppose it has to be a very dense material to kill the noise and therefore heavy. Too heavy. 8-)

[Freewheeler]

Brian Kirby - 2010-07-23 1:14 PM

 

So, solar panels lose efficiency over time.  But, so do batteries.  So do engines.  So do we all.  So what?  How can that be a reason not to buy?  The argument is worse than a red herring, IMO, because it is fallacious and misleading, and so, unhelpful.

 

Oh dear, I seem to have upset someone!

Notwithstanding this, I feel that my views on Solar panels were given as a genuine contribution to this thread, and I certainly have no wish to receive comments like this, so I'll refrain from any more replies on this subject.

 

P.S. Was it because I disagreed with one of the regular contributors?

( Reminds me of my first visit to the junior debating society, at school! )

[Brian Kirby]

No, I am not in the least upset, and am sorry if I gave that impression.  However, your comments, however intended, are not helpful because, IMO, they raise spurious disadvantages to the use of panels.  The OP was seeking knowledge, so he must be assumed less knowledgeable.  To feed spurious knowledge to someone who seeks accurate knowledge is not helpful.  I have stated my reasons for saying this.  If you can substantiate any of your claims regarding increases in fuel consumption, in any meaningful and useful way, please do.  Otherwise, I remain deeply unconvinced. 

No offence is intended by this.  You wrote: I strongly disagreed.  That does not imply that I am offended.  :-)

[Guest JudgeMental]

well thanks to this thread, I have removed the solar panels from wish list on new van. Will see how we get along.....I always have twin batteries and have managed up to now.

[Clive]

Modern solar panels do loose efficiency over time but the rate is very slow and should not deter anyone from taking one from van to van to van.

 

C.

 

 

[Yeoman]

Actually I have just looked up some information on generators, and these modern ones emit less noise than normal conversational noise!

 

As it happens I think I won't buy either a genny or a solar panel. We mostly wild camp, often alone, but never stay longer than a few days for the simple reason that we get bored, and want to move on. Quite honestly, if we wanted to stay put, we would buy a caravan instead.

 

As someone else has said in so many words, it's horses for courses. If you want to free camp, but stay put for a month or more then maybe you do need a solar panel. If you are a more mobile motorhomer, then it isn't worth having a solar panel. That is the conclusion I've reached.

 

 

 

[747]

I also wildcamp and rarely use a site. What I have found is that 2 days in Winter takes its toll when you have an Alde wet heating system on all day and night plus the other normal electrical usage. We can stretch it to 3 days but by that time, there is precious little left in the 2 x 110 ah batteries (new ones).

 

It is much better to try and keep putting some charge back in, even if it is a limited amount in winter. It is the cycle of deep discharges that shorten a battery`s life. So, there is a cost saving on batteries to offset the price of the panel.

Also, you move on. How far? If it is a short distance then you have not put much charge back in to your batteries and if you travel further, then that is costing you more money in fuel due to the need to top up your batteries.

 

This motorhoming lark is not as straightforward as it seems. :D

[Freewheeler]

Brian Kirby - 2010-07-23 7:21 PM

No, I am not in the least upset, and am sorry if I gave that impression.  However, your comments, however intended, are not helpful because, IMO, they raise spurious disadvantages to the use of panels.  The OP was seeking knowledge, so he must be assumed less knowledgeable.  To feed spurious knowledge to someone who seeks accurate knowledge is not helpful.  I have stated my reasons for saying this.  If you can substantiate any of your claims regarding increases in fuel consumption, in any meaningful and useful way, please do.  Otherwise, I remain deeply unconvinced. 

No offence is intended by this.  You wrote: I strongly disagreed.  That does not imply that I am offended.  :-)

I said that I would not contribute anything else to this thread, but in light of Brians reply, I will substantiate what I said regarding effects on fuel consumption, although I am surprised that this is necessary, because it is common knowledge, and well documented. Akin to having to prove that the world is round! Spurious knowledge? Can facts be thus described?From my recollections of basic physics, moving any mass requires energy. Obviously, where vehicles are concerned, energy means using fuel.In the early seventies, when there was a fuel crisis, the DOT and all the motoring organisation published details of fuel wastage.These included such things as roof racks and carrying extra weight. Indeed, Shell are currently publishing this same information as part of their publicity campaign to promote their new fuel. Anyone wishing to find out more can easily access their website.Much of the information is particularly applicable to our motorhomes because many of us fit various accessories to the roofs and often carry unecessary weight. My point is that Solar panels are no different, in this respect, but many seem unaware of this, so I thought that my contribution was entierly relevent to this thread.

[Yeoman]

We don't move on for the purpose of recharging the batteries - we move on because we want to! We get bored. Therefore the cost is part of our holiday, and deisel is not so expensive when you drive a smallish van!

 

Staying in one place is bad for the vehicle anyway. Let's face it, motorhomes are designed to be mobile, unlike caravans which can happily stay put indefinitely.

 

We are all different, and many of you will be happy enough to sit tight for months just as we are happiest moving on every few days.

[Yeoman]

You've probably hit the nail on the head - "fit various accessories to the roofs and often carry unecessary weight"

It is likely to be the various accessories, draining the system, that dictate the need for the solar panel in the first place!

 

 

[747]

Hi Yeoman,

 

We do not necessarily want to stay in one place for a long time but would like the option. Recently, we stayed on a C&CC Temporary Holiday Site at Weymouth. We had no fixed plans but it was a friendly and interesting place and a lovely view. We decided to stay there a full week. Luckily there was a couple of windy days to use the wind turbine but we still had to have a good run out for the batteries sake. A Solar Panel would have made that unnecessary.

We will be returning to the West coast of Scotland very early next year when there are virtually no other vans there. It is very hard to move on when you find the right spot with beautiful views and not a soul in sight. Last year, it was forced on us by the batteries.

 

As for losing mpg by fixing a panel to the roof, we have 3 rooflights, 3 air vents, the oven flue and a Status aerial up there already. A panel or two would make no difference to the aerodynamics.

[Brian Kirby]

Freewheeler - 2010-07-24 8:26 AM .............I will substantiate what I said regarding effects on fuel consumption, although I am surprised that this is necessary, because it is common knowledge, and well documented. ............

What I originally said was: "Any extra weight or increased aerodynamic characteristic will increase fuel consumption.  The question is, by how much, and whether that increase in running costs is significant, either relative to the costs of owning and running a van, or to the benefits from the panel."

Surely my first sentence above acknowledged the facts as you set them out?  It is of course self-evident that added weight and aerodynamic resistance increase fuel consumption.  But by enough to be relevant to deciding whether or not to fit a solar panel?  Really?  It is that element of your earlier comment I regarded as spurious.  That is what I asked you to substantiate: not the self-evident truth, but the quantum.  Re-stating the obvious does not, with respect, add that vital quantum.

As you appear to think I am being unreasonable, I will explain.  First, there is no standard motorhome design, and so far as I know no aerodynamic testing of vans, so there is no base from which to begin a comparison.  The affect on aerodynamics will vary from van to van.  Some, I would guess, would be unaffected in measurable terms (through the panel being out of the airstream, behind a luton, rooflight, satellite dome, or similar), others perhaps just measurable.  But, to be helpful in deciding whether or not to fit a solar panel, that quantum needs to be calculated.  X litres per 1,000 miles, or some such, so that its cost disbenefit can be set against the cost benefits of the panel.  That is the (I think unanswerable) question I am challenging you to answer, because merely muttering "there must be some" - which I'm afraid seems to be where we are, really doesn't inform choice.

The case with added weight is much the same.  An 80W panel, selected at random, is claimed to weigh 7.1kg by its manufacturer.  That is 0.2% of the weight of a 3.5 tonne van.  So, you tell me how much extra fuel that additional 7.1 kg load will consume.  Some, undoubtedly, but sufficient to put fitting a panel into contention?

That is my point, and that is why I said I think your contention spurious.  I'm neither an advocate of solar panels, not a detractor.  I have no axe to grind.  But I really cannot see the point of raising issues that are of such infinitesimally small consequence for the decision, that they are incalculable.  To that extent, they seem to me spurious: hair splitting, to get in the way, not to advance the topic, not to assist decision making. 

So, I'm sorry, but that is my view.  Having said that, I would hate one disagreement to be the reason for someone taking umbridge and not wishing to contribute further.  I certainly do not expect everyone to agree with me, which is why I usually give the reasons for holding my views.  This string was about solar panels, and not about fuel consumption, so my apologies for digressing.

[Yeoman]

I do agree. The main reasons for buying or not buying a solar panel seem to be the way you use the van. I have been trying to be devil's advocate somewhat in the hope of bringing out some more points to help with decision making.

 

I suppose many of us are wary of 'jumping on the bandwagon' for the sake of it.

 

I would need to know a lot more about solar panels than has come out here.

 

[Tomo3090]

We have 2 X110 Amp leisure batteries on oujr van and wanted the freedom to stop longer on aires or if we found a good freecamping place, like we did in Sicily last year, for more than the 3 or so days the batteries limited us to. We also mainly use CL/CS sites where hook up isn't always available. So we had 2 X85 watt panels fitted last September at Leisurepower in Warrington The total cost was £1,145, and whilst we were lucky to have the cost offset by a pressie from my Mum, we would still have found the cash from savings eventually.

 

Since then we've had periods of up to ten days of staying in one spot, to driving short distances where the engine wouldn't have topped up the batteries enough. (This has also been right through the winter and included a week in one place.) We've never had to have EHU in all that time.

 

We have an inverter that we have used to charge the lap top and my electric toothbrush! We have equipped our van with as much 12V equipment as we can to replace 240V stuff. A hairdryer, slow cooker, t.v. Pace Sky box etc. Autotrail kindly and cleverly fitted LED lights when they built it!

 

As some have said I don't think you could do a full cost effective study on solar panels. You either think you'll need them and get them or think of another way, gennie/Efoy.

 

We did and I would recommend them to anyone who uses their van on sites without hook up, aires or freecamps.

[Freewheeler]

I too am neither for or against solar panels. My previous post suggests taking a look at Shells fuel saving website. This gives the aproximation of extra fuel consumption regarding such things as roof racks ( Not unlike roof mounted solar panels), and carrying extra weight.

I have already agreed that these aren't excessive, but, given that fuel prices are set to rise more and more, I still believe that this issue is relevent to this thread. I certainly wouldn't deny other people their opinions, but I would take the (rising) fuel consumption info into consideration, before having a roof mounted solar panel.

 

Individual camping requirements are, as we all seem to agree, key to this.

Our camping style might change, as we get older, so I might have to consider solar panels myself. Over the last 30 odd years as a motorhomer, however, I haven't needed solar power, and anything that increases my fuel consumption, however slight, will affect my decision to buy it.

 

[Barrypat]

Just to throw another spanner in the works, I purchased my last van second hand that came with a 75W solar panel fitted on the roof. I probably fall into the category of constantly checking the battery state and telling my wife to turn lights off. I must say it has exceeded all my expectations, obviously the sunnier it is the better, spent March to June in France and Spain, in total spent four nights only on ehu. In one area we stayed put for two weeks, no problems with batteries at all.

Would I pay for a panel on our next van? probably, and this is where I would give a word of warning. I am a very practical man ( engineer) so would have no hesitation installing a solar panel myself, I realise not everyone would be confident in drilling holes through there roofs and so would recommend them to do some homework before entrusting this job to a third party.

The person who owned our van previously had the solar panel fitted by a well known company, handed over his cash and drove away happy.

Unfortunately I was'nt as happy when I discovered water dripping into the locker where the wire came in, at the time we were pitched a bit unlevel ie. sloping sideways to the side where the panel is mounted.

On our return home I removed the panel to gain access to the cable entry which could not be seen as it was hidden under the panel, not the best place I feel, I could not believe how shoddy the work was in the sealling of the cable entry, I removed the whole lot and started again, I also removed and resealed the cable entry for the Sat dish, I dont think this was leaking but I was not happy with it.

So if any of you are thinking of having a solar panel fitted please make sure you are getting a good job done or better still, do it yourself.

I dont wish to offend the quality installers out there, I am sure most of them are excellent, but when it comes to drilling holes in roofs and the possible consequences of water ingress, we as consumers need to be extremely vigilant, fortunately for me the roof does'nt seem to have suffered any long term damage.

 

Regards Barry

[art338]

To comment on the original question, we have no need for anything other than batteries, 2x90 last us 3 days we are radio people (internal batteries) and the pictures are better.

 

Our views on driving a Motorhome are just do it regardless of the cost; penny pinching over trivial items is a waste of valuable camping time surely.

 

Save pennies on a certain item and the next road you take is uphill all the way so how does that equate to a saving, on the contrary if driving amongst a heavy volume of traffic its practically free motoring.

 

Perhaps those so concerned on saving a penny should wait until they have a prevailing north-easterly before heading to Cornwall.

 

I say forget it all and do what you will. If you really need to save then stay at home.

 

art

 

 

 

[tonyishuk]

Maybe an alternative plan if you have suffcient battery storage and move on before it runs out is to consider a battery to battery charger.

 

The charger should ensure your batteries are charged to maximum capacity before the next stop.

 

http://www.ctek.com/EN-GB/home/Default.aspx

 

http://www.sterling-power.com/products-battbatt-info.htm

 

Roadpro can advise and sell, although there are cheaper outlets.

 

Rgds

[weldted]

my two penneth, van Bessacar 765 march 08 MAM 4250 kg, 3 litre manual, basic van with two 110 amp leisure batteries. 6,000 mile first trip max speed 50-55 mph average fuel 23 mpg. Second trip extras fitted, Two 90 watt solar panels, third 110 amp leisure battery, 2.5 kw lpg on board genny (60 kgs) Oyster 85cm auto sat system, stirling 50 amp bat to bat charger, 55 litre gas tank, spare wheel (not supplied originaly) 5,000 miles Denmark,Norway, Sweden. same ave speed 23 mpg. Ok so the engine has run in but we are now at 29,000 miles and stil get 23-24 mpg. we find the fuel increases if the van is dirty. As to the wind drag increasing fuel, power has to be found from somewhere to recharge the batteries. without the solar panels which are Sunpower and are very efficient the alternator would have to work harder to put amps back into the batteries which makes the engine work harder and so may well cause the engine to use more fuel. all I can say is i have found in the last 13 days the van has been parked up without hook up and we have plenty of power in the batteries even with the tv on a lot and using an inverter to charge my laptop, I know it is mid summer but we spent 30 nights in Portugal last Nov.Dec with low sunlight but still managed with out hook up for that amount of time with only four hours help from the genny. You pays your money and takes your choice.

[BGD]

weldted - 2010-07-28 10:07 PM

 

my two penneth, van Bessacar 765 march 08 MAM 4250 kg, 3 litre manual, basic van with two 110 amp leisure batteries. 6,000 mile first trip max speed 50-55 mph average fuel 23 mpg. Second trip extras fitted, Two 90 watt solar panels, third 110 amp leisure battery, 2.5 kw lpg on board genny (60 kgs) Oyster 85cm auto sat system, stirling 50 amp bat to bat charger, 55 litre gas tank, spare wheel (not supplied originaly) 5,000 miles Denmark,Norway, Sweden. same ave speed 23 mpg. Ok so the engine has run in but we are now at 29,000 miles and stil get 23-24 mpg. we find the fuel increases if the van is dirty. As to the wind drag increasing fuel, power has to be found from somewhere to recharge the batteries. without the solar panels which are Sunpower and are very efficient the alternator would have to work harder to put amps back into the batteries which makes the engine work harder and so may well cause the engine to use more fuel. all I can say is i have found in the last 13 days the van has been parked up without hook up and we have plenty of power in the batteries even with the tv on a lot and using an inverter to charge my laptop, I know it is mid summer but we spent 30 nights in Portugal last Nov.Dec with low sunlight but still managed with out hook up for that amount of time with only four hours help from the genny. You pays your money and takes your choice.

 

 

 

 

I'm confused by your comment about the alternator having to "work harder.....which makes the engine work harder" without your addition of solar panels.

 

I'd always believed that the alternator is spinning all the time, driven by a belt from the end of the engine crankshaft, and is thus generating electricity whether the vehicle/leisure batteries need it or not.

It's the voltage regulator thingy which decides whether that generated electricity is fed on through to those batteries or not.

 

Because the alternator is driven/spun by engine revs all the time, I don't see why having/not having solar panels would make a jot of difference...the alternator does not "load" the engine (ie sap it's energy) any more when the voltage regulator is passing its charge through to the batteries, than when it is preventing that passing of electricity because the batteries are full.

 

Or am I missing something?

 

[AliB]

BGD - 2010-07-28 11:28 PM

 

I'm confused by your comment about the alternator having to "work harder.....which makes the engine work harder" without your addition of solar panels.

Have a look at page 1 on this thread.

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=19940&start=1