We used to have an 80w, with a 110ah battery. Ran 12v tv for a couple of hours evenings, 12v lights, charged phones/tablets, although we would charge phones in car whilst out and about too. Also recommend changing all bulbs to LED. There's only two of us, that set up easily did a weekend, and we did 8 days in Northumberland last year with no problems. On our new van (new to us, not brand new) we've had a 120w fitted on the roof. Lights are already LED, but the van has no heater, only blown air, so this will put a bit more drain on the battery in the winter as it has to have the 12v fan on.
150w folding panel, 110amp battery, 12 nights away no problem, also use a small inverter to charge phones etc.
Have also used it in February for 4 nights (No EHU) and using Alde heating (12v circulation pump) with no problems, when we left the battery showed 12.7v
Re cost a lot less if you look on eBay or Amazon, than if you buy from your local friendly caravan dealer. But it depends on what you want and what size.
It is worth saying that a roof mounted panel is less efficient than a freestanding one. I have a roof mounted panel simply because our van is in storage so it keeps the battery topped up and charged.
Mine cost around £220.00 inc. a hard carry case, the weight is 17kg something to consider when loading. Have a look on e-bay, however, look at the rating of the panel controller, make sure it is waterproof, some are not!! and state 'cover in heavy rain'!!
We have a 100w panel roof-mounted, dealer fit £200. We only really use it to keep the battery topped up whilst in storage but last year one site had a 48 hour power failure and we managed ok, LED lights but we did watch the tv as well!
The size needed and where it is located depends greatly on the time of the year you want it to support off EHU camping.
Realistically in the UK using solar for a winter holiday can be "challenging" needing good fortune with successive bright sunny days, and a discipline in not using too much power overnight. Even then a roof mounted panel is far less effective than one that can be tracked to face the sun, tree shadows allowing. IME relying on solar over the winter months is not a sound option.
Come the spring, summer and autumn months things change radically. The yields jump and being roof mounted does not inhibit things very much.
We have a freestanding 85 Watt, high-quality [Kyocera] panel now 9 years old and still performing well. It charges both the caravan's battery and when taken a portable battery used for the TV system. The controller is a Morningstar Duo that automatically recognises the batteries and their individual requirements.
These days panels are about a quarter of the price they were 10 years ago, making going for something of decent size "affordable" and IMO it is pointless going smaller than about 80Watts, ideally, go for 100 as a decent compromise in weight and bulk versus performance.
Just for looking after a battery whilst in storage a more modest system will cope.
I have a 50w freestanding Kyocera panel and a Morningstar Sunsaver controller, led lights and telly.
I can go away during summer for weeks on end without a problem.
For winter use I add 2x20w to the 50w panel.
I'd also say the same as JTQU, the price nowadays means you can go for a bigger panel, my first panel a 12w cost £80+ 30 years ago, my 50w Kyocera cost the same as 1 of my 20w panels 5 years later and the 50w I stuck on the roof last year for overwinter charging cost £50 it works ok but with hind sight I should have stuck a 80w on.
The next question you should ask is what controller will give me the best results from a solar panel, I'd say a Morningstar and fit it relatively close to your battery.
Having had the caravan broken into in secure storage the battery was flat and the alarm inoperative, I fitted two Eco Worthy 100 watt semi flexible panels connected in series as this doubles the voltage rather than parallel which doubles the amps the idea according to the expert is that on a less than perfect day, is that the two panels producing less voltage than the 18v (36v combined), to say 8v each this is doubled to 16v which will maintain the battery. The cost of the two panels was around £260 these are connected to an EP SOLAR 30A MPPT Tracer- 3215BN 30 Amp 390W at 12V, 780W at 24V with a MT-50 display/control Unit, cost £169 these units are more efficient up to 30% than a standard PWM charge controller the MPPT charge controller converts any excess voltage into Amps where the PWM controller just wastes the excess voltage.
This now keeps the battery topped so the alarm is constantly armed and I have added an auto dialer so I am instantly notified if the caravan is broken into. I have yet to try it with no electric hook up though considering the bad weather we have had, it has performed better than expected and I can add another panel if needed as the charge controller is more than capable of handling 300w and 54 volts the three panels could produce.
The total cost with extra cable, a roof sealing unit, Sikaflex 512, isolator switch, a switch to change over from solar charging to mains charging and fuse came to around £500.
Beware of some panels on E Bay they are falsely rated these are usually the 150 flexible panels these also cannot be connected in series as they are sealed in silicon and may overheat. The Eco Worthy panels have an aluminum backing and are a fraction of the weight of conventional panels mounted in an aluminum/glass frame which is an important consideration for not overloading the caravan.
I will be fitting a 2000w inverter at some point so we can use a microwave etc, when traveling on the continent and when parking with no EHU usually in between home and destination.
Fitting the system was quite simple though this will vary from caravan to caravan requiring the panels to be bonded to the roof, two holes to be drilled in the roof for the cable then routing through to the controller and on to the battery and needs careful planning before starting on my caravan it needed only the holes through the roof to be drilled into a void by the cupboard and down behind the heater through to the front seat where the main electrics are.
I have found that it is better to research once you decide what usage you will need don't be afraid to phone reputable solar installers and ask questions they will tell you the system needed to match your requirements or whether your expectations can be met.
In storage is not an issue for us as we store at home in a shed at the back of the house and there is mains in the shed for top up trickle a few days a month to keep all healthy.
I have no idea as yet if we can manage a weekend on battery only. Tried to check battery for mAh rating and dont see it marked.
The caravan is 09 so I am pretty sure the lights are not already LED, hence a previous owner fitted AA led battery lights in 6 different locations in van. Our TV DVD combo is a 240V unit so thats a nono. but in decent weather the kids will be fine with no tv.
My only worry with a free standing unit is the wind. Last two nights the van was moving about a bit and we were lying still I promise....lol
Do you clamp the free standing units to A frame etc to stop the wind damaging them?
------------- if your not living life on the edge your taking up tooo much room
Quote:
The caravan is 09 so I am pretty sure the lights are not already LED, hence a previous owner fitted AA led battery lights in 6 different locations in van. Our TV DVD combo is a 240V unit so thats a nono. but in decent weather the kids will be fine with no tv.
My only worry with a free standing unit is the wind. Last two nights the van was moving about a bit and we were lying still I promise....lol
Do you clamp the free standing units to A frame etc to stop the wind damaging them?
Changing the built in light bulbs to LEDs is not difficult or now very expensive, and practically you only need to change any that are needed to be on for a while to see big savings in the energy drain. eg; loo lights [hopefully] are not on for long so not much energy drain there to save.
A mains TV is not necessarily a "no-no", I ran a SONY for many years using an inverter; however here you need to buy the "right" kit to not have a lot of extra losses.
The logical action on windy nights is to lay the freestanding panel down flat; it is not ever going to gather energy in the dark and flat it will not get blown over. Placing a panel by the van adds to the difficulties in avoiding shadows, plus if it "falls" it can dent the van.
In the summer months, panels don't need to be at the silly high angles the integrated stands of so many commercial ones place them. Actually, about 15 > 20 degrees off horizontal gathers the optimum energy, so if you make your own stand then it should be remarkably stable. I made mine for late season use at an angle of 45 degrees, but in the summer I fold its stand away and prop the panel on my fire bucket, just about the ideal angle and no great distance to fall.
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Topic: Solar panel for touring caravan
