solar panel (1 Viewer)

[gpz]

can any one tell me what is the biggest wattage solar panel you can get for a motorhome and are all panels able to be used for 12 volt may seem a silly question hope someone can help and any rough idea how much a panel costs to buy and fit

 

[pappajohn]

biggest i have seen is around 200watts.

physical size is a problem on motorhomes as there is already a load of stuff on/in the roof, they are also pretty heavy.

i have a 170watt panel which is around 6ft by 3ft

most are 12v but some are 24v

cost...100watt panel can be bought for around £80 on eBay up to a 200watt at several hundred quid.

 

[cmcardle75]

can any one tell me what is the biggest wattage solar panel you can get for a motorhome and are all panels able to be used for 12 volt may seem a silly question hope someone can help and any rough idea how much a panel costs to buy and fit

Panels come in lots of sizes, but you don't need a big one. Lots of small ones can fit better onto a congested roof for less money. Most panels are designed for 12V systems, but not all. I went for semiflexible panels, as they are much easier to fit and are much lower profile, so don't affect appearance and fuel economy so much.

Make sure you get a decent solar charger. I got a 200W semiflexible system for about £300, but fit it myself. Seems to work pretty well. My mains charger is broken (110V 35 year old US system) and the split charge is only working on manual, so I'm using solar only at the moment, but never run out.

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[SomeoneElse]

can any one tell me what is the biggest wattage solar panel you can get for a motorhome and are all panels able to be used for 12 volt may seem a silly question hope someone can help and any rough idea how much a panel costs to buy and fit

The controlling factor is the controller. The older PWM controllers operate at fixed point on the panel's IV curve. This is around 17 to 18 volts so optimised for 36 cell or "12V" panels. The newer MPPT controllers can take a range of input voltages up to 100V or more.

Domestic panels will have 72 to 96 cells and a optimum voltage of 30 to 40V, these aren't suitable for a PWM controller. Whether these are strong enough to cope with the vibrational loads they would experience on the roof of a motorhome is an entirely different matter.

 

[gpz]

solar panels

thanks for the replys guys,so its the controler that i need to be choosy about ,my problem is my fridge is just 12v so all thought i have a 235 amp i think battery it soon runs it down so thinking solar panel is the way to go anyway thanks again

 

[maz]

thanks for the replys guys,so its the controler that i need to be choosy about ,my problem is my fridge is just 12v so all thought i have a 235 amp i think battery it soon runs it down so thinking solar panel is the way to go anyway thanks again

Running a fridge off 12v all the time would need a whole load of solar panels! Presumably you have a compressor fridge then, rather than the more usual type that normally only run on 12v when the engine is running.

Also 235 Ah is a weird size for a battery ......... :Confused:

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[gpz]

solar panels

yes thats right Maz compressor fridge seemed a good idea at the time i justwent for the biggest battery i could find at the time i may be wrong about it being 235 amp hr i know its big takes up a lot of room

 

[maz]

yes thats right Maz compressor fridge seemed a good idea at the time i justwent for the biggest battery i could find at the time i may be wrong about it being 235 amp hr i know its big takes up a lot of room

Guess battery could be 235Ah then if it's massive. Must be a pig to lift out when it needs changing!

 

[steevie]

with a good sized solar panel you should have no power problem with a battery that size, but I dont know how well it would do with your compressor fridge. I have a 250 watt solar panel, house type, which runs at just under 40v, and controlled with a 30 amp 12v[also does 24v] controller.[all from ebay] And two 100 amp hour batteries It is a large panel tho, about 6' by 3', bedded on sikoflex. We have had it now for over two years, and it copes brilliantly, as we never have hook up. Panel was around £200, controller was about £20, and sikoflex £12. You may need smaller ones according to your roof space, but they are easily joined together.

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[Dubiousp]

I bought a 100w unit of EBAY about 8 weeks ago with a cheap MPPT controller fitted the roof lovely and charges a treat,, I admit weve had sun but even evenings give a trickle

 

[gpz]

solar panels

has anybody fitted any of the flexable solar panels it seems there is a lot of weight saving but do they give the same output as ordinary panels and are there any drawbacks apart from price

 

[Techno]

Yes they get hot due to lack of air circulation. Heat causes reduced performance.

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[cmcardle75]

has anybody fitted any of the flexable solar panels it seems there is a lot of weight saving but do they give the same output as ordinary panels and are there any drawbacks apart from price

Yes, I have two. Much easier to fit as they don't need brackets, just glue or screw down. Better for fuel economy as they don't jut out into the slipstream. Better for appearance, as you can't see them unless you look down from above.

 

[gpz]

solar panels

can anyone tell me what is the quality difference between chinese solar panels and thoose made in this country chineese ones seem to be cheaper

 

[Techno]

can anyone tell me what is the quality difference between chinese solar panels and thoose made in this country chineese ones seem to be cheaper

Are there any made in this country? or just badged up by UK sellers at higher prices

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[gpz]

solar panels

i dont know thats what i wasnt sure about ive seen a few posts saying steer clear of chineese one just wondered if there was any particular reason

 

[Techno]

They are not all the same.
Visual inspection of the quality of assembly is enough for me to decide. With any panel if it looks shabby it is! I've had 80 watt panels at £75 that are/were superb. The 3x100 watt on my current van are first class at £108 each in January. I've had branded AKT that was at a premium price and poorly assembled.

 

[gpz]

solar panels

so do you have the flexy panels or the rigid ones i was looking at the flexy ones just really for the weight saving

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[Techno]

This is my current instal

 

[Techno]

3 Spanish made panels bought from ebay Germany just fitted last week to a Niesmann
Link Removed

 

[Techno]

2 Chinese on a Burstner over a year ago
Link Removed

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[Techno]

2 more Chinese on a Autotrail Grande Frontier nearly 2 yrs ago when these were £150 each. Came down to under £75 this year
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[vwalan]

i have bp panels on my roof came from bp in spain . but made in india .
tat bp solar india ltd.
plot 78 electronic city .
hosur road'
bangaore 561 229 india .
telephone +91 80 40702000
it seems most are made there for bp.
they were 150 quid 4 yrs ago .(80w)
first 3 x80w were eurosolar made in italy .

very similar to the ones techno fitted on his . just about all look identical. though mine are poly .
fitted an old shell panel sold by solaera in hamburg germany years ago . mono but a 50w was 400 quid about ten years ago.
all work well . there is a slight drop between the older panels and the new ones but they work .
many try to frighten you into spending more .

 

[Techno]

My 3x100 were bought from the seller Afrescobay on ebay. They sold out and I hear theyre not re stocking until it is clear about the pricing policy and TAX

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[gpz]

solar panels

thanks for the replys guys i have a van conversion so space and weight is at a premium
so i will go for the flexy one and just buy from somewhere that has good feed back thanks again

 

[gpz]

Solar panels

Well I have bought a flexy solar panel for the weight as much as anything has anybody fitted these .have you stuck the,m to the roof or raised them up a bit I was thinking of bonding 4 bolts to the roof to fix it to but not sure whether sikaflex would be strong enough any help and thoughts appreciated

 

[Ed Excel]

Are there any made in this country? or just badged up by UK sellers at higher prices

Apparently not! Just look here:
Broken Link Removed

Alternatively, wonder why they don't list Solarcentury, Romag(UK) and Veridian (UK). This industry's moving so fast a list like that's out of date in no time!

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[ivorantony]

Have fitted 3 flexi 100w panels to my roof with silkaflex, as long as the roof and panels are degreased and with a good keyed surface there won't be a problem,
The small reduction in output because of heat is offset using a MPPT controller,
And I prefer the smooth look to the roof without big lumps of angle brackets sticking up in the airflow, they are also less likely to be damaged by low branches as there height is below the side rails of the roof,

 

[gpz]

solar panels

hi ivorantony ,thanks for your reply what difference does the mppt controler make bearing in mind i know nothing about electrics and can i ask how you degreased your van roof ,did you run a bead of sikaflex right around the outside of the panel or 4 blobs one at each corner as i am not sure how strong the sikaflex is

 

[ivorantony]

Hi GPZ
I used brake cleaner to degrease and 400 grit wet and dry to key the surface,
Then another wipe down to remove dust, marked out the shape of the panel with pencil, run masking tape around just outside your pencil mark,
I used a bead of silkaflex all the way around, use rubber gloves so you don't regrease the panel when you lay it in place, gently press down until fully seated,
A small amount will ozz from the sides onto the masking tape,
Remove tape carefully and run a finger around the edge to finish off,
If you ever needed to remove them it should be possible to put a thin blade under the side to cut the bead then clean up the roof,
The MPPT controller is more efficient than the PWM type so will offset the slight loss your panels will have with no cooling,

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