hi,
still planning to go off-grid and narrowed things down through advice and research. Can anyone share experience on the following:
- planning to get a 150w solar panel - will it work more than lights (possibly microwave 800w for 5-10 ins per day and charge laptop for an hour per day). No TV or radio.
- any insights on pro/con of (semi-)flexible panels? I may or may not move about much but weight is an issue as I need to carry on my own.
Thanks and happy camping all!
------------- Barbara
- enjoy life, this is not a rehearsal -
Seen a few reviews lately on flexible panels and they are slightly down on output compared to fixed panels. The issue was that most testers didnt flext them in fear of breaking them.
800w microwave wow.. Your 150w panel will be putting out less than 1/3rd during the winter so 50 watts if your lucky.
Pulling nearly 70 amps from your battery wont be good for it. How big is your battery bank?
Imagine cranking the engine on a car continuously for 5 minutes or so. The battery will be well depleted and the wiring will be super hot.
Im confused about your actualy idea and requirements, you appear to be feeding us tit bits of info, without the whole picture.
Your going off grid and cannot use a car to charge stuff, but you may move around?
10 minutes of microwave use will take approx 160 minutes of fairly decent sun to put anywhere near that amount of power back.
Watch the panel reviews (UK ones only) and you will see how unfuruated they get when a clou blocks the sun and kills the output.
The battery wont last long providing that power though.
Is it a 12v microwave or will you be using an inverter? Going to need a big one.
Is the output 800w or the input? My 700w microwave uses 2200watts.
You mention semi flexible panels so are considering a roof mounting?
Mounted horizontally will put the panels at a great disadvantage relative to at 90 degrees to the sun, on sunny winter days as the sun angle is so low. On bright sky days the relative loss will not be quite as bad, but the yield is still inevitably very low.
They are brilliant in cloudless winter days if targeted at the sun, but this targeting requires a great deal of moving the panel about, so getting off site is limited.
In the bulk of the UK with its trees and winter sun down to just 16 degrees to horizontal, solar panels are doomed to poor performance. Some improvements can be obtained with higher voltage panels and MPPT controller technology and by grossly over sizing the panels, but it becomes all a bit impractical as a power source till the sun rises to higher angles.
My 150w folding panel weighs 18kg, had 4 nights away in February and at mid day in good sunshine 14.4v was going into the battery, much less when cloudy, however my battery (110amp) was at 12.7v when the panel was disconnected and ready to set off home. Caravan is all LED lighting, Avtex TV draws 2.9amps used it approx 3 hrs a night, other draw is the Alde heating pump, around 0.5amp, on most of the time. When we went off for the day, just turned the panel to get the best of the sun around midday.
There was plenty of winter sun for our stay. The photo was 9.00am it was in full sun later until around 3.00pm
This is the predicted output two of our farms. The kWp is shown above each. They are fixed in position and inclined
Badminton – 245.52 KWp
Month % of yearly production (PV GIS) Production per month (kWh)
January 2.79% 6,446
February 4.43% 10,235
March 8.28% 19,130
April 10.93% 25,252
May 13.15% 30,381
June 13.25% 30,612
July 12.96% 29,942
August 12.09% 27,932
September 9.72% 22,457
October 6.52% 15,063
November 3.81% 8,802
December 2.07% 4,782
Total 100.00% 231,034
Moorend – 748.65 kWp
Month % of yearly production (PV GIS) Production per month (kWh)
January 2.79% 20,135
February 4.43% 31,971
March 8.28% 59,757
April 10.93% 78,882
May 13.15% 94,903
June 13.25% 95,625
July 12.96% 93,532
August 12.09% 87,253
September 9.72% 70,149
October 6.52% 47,055
November 3.81% 27,497
December 2.07% 14,939
Total 100.00% 721,699
Hi Octavia 4x4
seen your posting ,your system looks just what im after,
Can you tell me any more details about your solar panels
eg, make ,price and where you got it
nobody seems to be talking make or price on the forum
Hi Octavia 4x4
seen your posting ,your system looks just what im after,
Can you tell me any more details about your solar panels
eg, make ,price and where you got it
nobody seems to be talking make or price on the forum
However the folding panels do not seem to be listed anymore! maybe call or email them. Panels are Bosh with a sunsolar controller fixed at the rear of the panels with 5m of cable to battery, 15amp in line fuse fitted. Cost £220 with a solid carry case to put them in and free postage. I took the croc clips off and fitted a cig lighter type plug for the solar socket in the battery box.
With regards to the source of solar panels the solar cells have pretty much become commodity items sourced in the Far East. Bosch have for example sold its SP division because they can't make it pay.
A folding pannel is really only two panels hinged together
Purists will tell you that the control should be place as close as possible to the battery for maximum efficiency however not sure how much difference it makes in the real world
Comment afaik the socket shown in Octavia 4x4 post has a maximum rating of 60w so a bit undergunned for a 150w panel.
For the record I have a 150w panel roof mounted which is less efficient than a properly aimed free standing panel, but more convenient for us. I have also fitted 2x 100W batteries to put the power and all lights are LED to reduce the amount of power needed.
Quote: Originally posted by boff on 13/11/2016
Just a couple of comments.
A folding pannel is really only two panels hinged together
Purists will tell you that the control should be place as close as possible to the battery for maximum efficiency however not sure how much difference it makes in the real world
Quite a bit if electricity really does what the laws say. With a 100W panel and quite heavy 1.5 mm square two core cable, 6 metres long the overall voltage drop to the battery from a regulated 14 volts, at full power works out at about 1.8 volts; I doubt a charge at 12.2 volts will do much at all. This is before you take into account the hot rear of the panel will instruct the regulator to back off that 14 volts anyway. Things will sort themselves out a bit but the end result will be a much poorer performance than could be the case.
Edit: At low yields from the panel things rapidly get less of an impact. Firstly the current is down and the losses are driven by current squared, and of course the panel is colder so the temperature compensation in most half decent regulators will be less. Placing a regulator on the back of a panel is technically naff but expedient.
Another big and forgotten issue with these folding panels are most are placed on the ground; there any traces of grass etc shadows knocks loads of potential from the panel's performance. Stand it on a sheet etc.
Quote: Originally posted by boff on 13/11/2016
Comment afaik the socket shown in Octavia 4x4 post has a maximum rating of 60w so a bit undergunned for a 150w panel.
The socket is rated at 10amps (fused at 10amps) max output of panels just over 8amps.
Quote: Originally posted by Octavia4x4 on 14/11/2016
Quote: Originally posted by boff on 13/11/2016
Comment afaik the socket shown in Octavia 4x4 post has a maximum rating of 60w so a bit undergunned for a 150w panel.
The socket is rated at 10amps (fused at 10amps) max output of panels just over 8amps.
That's fine the reason I raised it was simply I had one of those plugs rated at 5amp. The difference was the part that you plug into was made from the same plastic as the rest of plug. In the 10amp version it was made from a white thermosetting plastic.
However the folding panels do not seem to be listed anymore! maybe call or email them. Panels are Bosh with a sunsolar controller fixed at the rear of the panels with 5m of cable to battery, 15amp in line fuse fitted. Cost £220 with a solid carry case to put them in and free postage. I took the croc clips off and fitted a cig lighter type plug for the solar socket in the battery box.
I think those cables in your image look a bit under sized and are probably automotive cables. There are special cables now for solar panel use, complete with their own type of error-proof connectors to ensure correct polarity. These have soldered connections for the wires, and large contact area at the connectors, for minimum voltage drop/reliability. The contact area of the positive pin on that 12 accessory connector is very small indeed, as they are rounded off.
Proper stuff readily available on eBay
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Topic: experience with solar panel in UK winter
