Winter Solar

[Asterix]

I'm starting to think about solar panels and wondered how many watts would be required to get thru a UK winter,I need to charge tablet,phone and dongle,run a fridge and also have enough for a few hours TV.
I understand there's not a great deal of sunlight hours,and what there is,is at a low angle,so what do people think I would need to get a charge into the batteries?
Would it be a big advantage to have panels that could be raised to get a better angle?
Thanks for any input,Dave

 

[harrow]

I'm starting to think about solar panels and wondered how many watts would be required to get thru a UK winter,I need to charge tablet,phone and dongle,run a fridge and also have enough for a few hours TV.
I understand there's not a great deal of sunlight hours,and what there is,is at a low angle,so what do people think I would need to get a charge into the batteries?
Would it be a big advantage to have panels that could be raised to get a better angle?
Thanks for any input,Dave

Yes being able to angle the panels will help but you are going to need about 1KW of solar to survive a winter.

 

[Asterix]

Yes being able to angle the panels will help but you are going to need about 1KW of solar to survive a winter.

I have to go with what I can afford this year,which is around half that,but next year I can probably add another 500 watts but it gives me some idea what I should be aiming for,thanks.

 

[mistericeman]

I'm starting to think about solar panels and wondered how many watts would be required to get thru a UK winter,I need to charge tablet,phone and dongle,run a fridge and also have enough for a few hours TV.
I understand there's not a great deal of sunlight hours,and what there is,is at a low angle,so what do people think I would need to get a charge into the batteries?
Would it be a big advantage to have panels that could be raised to get a better angle?
Thanks for any input,Dave

Do what we do and just move around.... And let our durite VSR
We have 2 x 100w solar panels on the roof to charge 3 x 100ah leisure batteries, powering a 3000w inverter to run our microwave /toaster /kettle/slow cooker etc
As well as eberspacher/waeco coolbox/TV etc
However solar does very little in winter so VSR does the heavy work as we tend to move on each day.

 

[Asterix]

Do what we do and just move around.... And let our durite VSR
We have 2 x 100w solar panels on the roof to charge 3 x 100ah leisure batteries, powering a 3000w inverter to run our microwave /toaster /kettle/slow cooker etc
As well as eberspacher/waeco coolbox/TV etc
However solar does very little in winter so VSR does the heavy work as we tend to move on each day.

I'd really like the option of not having to constantly move just for the sake of getting power but rather when I'm ready,so I'm aiming for self sufficiency in power and water collection. There will be times that I can be parked up for several weeks.

 

[mistericeman]

I'd really like the option of not having to constantly move just for the sake of getting power but rather when I'm ready,so I'm aiming for self sufficiency in power and water collection. There will be times that I can be parked up for several weeks.

Appreciate that....
Sadly though in the UK at least I reckon you are going to be up against it solar wise.

 

[wildebus]

I have been monitoring my Solar install since I fitted in last October, so that covers the winter months,including the snow etc that we suffered this year.
If of interest I can post a graph and you can review the difference between the winter and summer months to get a flavour of the difference?

In my situation, where I park I suffer from Shadow and that is much more pronounced in the Winter, as has been mentioned but even more so with my parking location so as has been said, the low sun angle can be a problem and selecting a good parking spot can make a major difference.

 

[Silver sprinter]

Hi wildest would be good to see your info, what about a nice generator, sounds good to me, and if anybody hangs around, you can let them plug in free, seems fair to me:lol-049::lol-049::lol-049::lol-049::lol-049:

 

[Asterix]

I have been monitoring my Solar install since I fitted in last October, so that covers the winter months,including the snow etc that we suffered this year.
If of interest I can post a graph and you can review the difference between the winter and summer months to get a flavour of the difference?

In my situation, where I park I suffer from Shadow and that is much more pronounced in the Winter, as has been mentioned but even more so with my parking location so as has been said, the low sun angle can be a problem and selecting a good parking spot can make a major difference.

A graph is probably the only way I'll ever understand anything to do with electrics,so please do put it up,real world stats would be good to see.

 

[Deleted member 2572]

I have been monitoring my Solar install since I fitted in last October, so that covers the winter months,including the snow etc that we suffered this year.
If of interest I can post a graph and you can review the difference between the winter and summer months to get a flavour of the difference?

In my situation, where I park I suffer from Shadow and that is much more pronounced in the Winter, as has been mentioned but even more so with my parking location so as has been said, the low sun angle can be a problem and selecting a good parking spot can make a major difference.

My electrician mate used to install solar and from what he was telling me the industry recognised Sunlight for UK winter is 1 hours :hammer:
Add a lack of sunlight to a bad installation angle and the results are pretty appalling, we worked out it would require approximately 4kw of panels to power the Winnebago :scared:
There are a fair number of motorhomes around now with large amounts of solar but even the guys with say 800 watts are only extending their season and still need ehu in winter.

 

[trevskoda]

I have 200w and can say in winter over a mth or two i get little if any charge from surface mount panels,after that from about late jan to april i get 1 to 3 ah over mid day which keeps the batterys up if sitting on driveway.

 

[hairydog]

The average sun is 5 hours per day in Summer, 1 hour per day in Winter, average 3 hours per day all year.

Then halve the power of the panel to allow for low sun angles in winter, and you can calculate that a 100watt panel will give about 50 watt hours per day in winter, which is around 4Ah.

But of course it isn't like that. You might get 20Ah one day, than nothing much for a week. Weather is variable, not least in winter.

 

[time4t]

If you mount some kind of reflective panel along side the panels you might get more power or you do what Rea & Ann (Streetsleeper) did & fit a wind turbine on the roof, it's often the case that when the sun doesn't shine the wind will blow!

Phill

 

[st3v3]

Angling the panel makes a huge difference, try and sort out something for that

 

[trevskoda]

Angling the panel makes a huge difference, try and sort out something for that

What about parking side ways on a hill.:wacko:

 

[wakk44]

Although I always advocate installing solar panels where possible,in winter they can't be relied on to produce any significant power and are about as much use as an ashtray on a motorbike.

If I'm away for long periods during the winter I always make sure I've got an ehu.

 

[jagmanx]

TV Fridge Phone/tablet

I suggest
1 TV is the main problem

2 Fridge should use very little in winter but....

3 Phone Tablet Dongle etc use very little

4 Internal lighting
I expect you have LED lights
But also get some battery powered LED lighting

(every little helps)
A second LB is a good idea

 

[groyne]

I've got a 150w solar panel on the van roof and it kept the batteries charged and compressor fridge running for most of the winter ( I did average about 200 mile a month driving as well). I switched the fridge off at the end of January.

 

[wildebus]

Ok, Graph as promised:

but first ....
1) This is not a scientific analysis (I don't drive around in a Laboratory!) and should be read more as a Comparision between different months and as an example of a single install.
2) I park just north of a 3-storey house so the impact of a low sun angle is exacerbated by that building. If I were to park just 5 feet further north-east, my harvesting increases noticably - even in the Summer, but more so in Winter (confirmed by occasional testing) - so IMO the difference shown between Winter and Summer is more extreme than it has to be
3) The Length of Day is determined by the time the Controller spends in either Bulk or Absorption Mode (it doesn't really harvest in Float Mode and definately not when Off!)
Plus - The Victron MPPT Controller is very efficient and attempts to harvest at first light and this is much earlier than real energy harvesting will occur.
This means the number of hours of Light/Day is a bit exaggerated really. For example, the average daylight hours in December, the shortest month is still 7.34Hrs! and in June, the longest month, it was 17.41Hrs. As a specific example, yesterday the Solar Controller turned on at 04:47 and turned off at 21:56 - but actual proper harvesting (over 5% of capacity) didn't start until 07:30 and stopped at around 20:30 - A pretty big difference.



SolarChart by David, on Flickr
So for the 10 months shown, difference between Winter and Summer is at a factor of 10 (this is more extreme then reality for reasons explained above).
Bearing in mind the elongated daylight times and the parking location pull the numbers down significantly, I harvest around 25%/Hr of the nominal maximum capacity of my array in the summer but just 2.5% in Winter.
My feeling is that those numbers are more likely to be 45% Summer, 8% Winter with true harvesting hours and optimized parking, so if that is true, 8% in winter will do as a 'tickover' kind of level, but to really USE your camper, either EHU or a Split-Charge (or Alternator) will need to be in place I would say.

On my 400W Array, I currently tend to average around 1Kw/Day when I am not doing much in it, and around 2.2Kw/Day when the Controller doesn't hit float mode for very long.

 

[Byronic]

The panels will supply some charge even on an overcast day
so long as there is some brightness.
But I reckon your going to struggle with reliance on solar panel
energy in blighty, you'd need an impractically large array I'd
say.
An LED TV of modest size say 19"will use around 14W/hour if
you shop around. Best if you get one that works direct off the 12v
supply ie no mains invertor.
IIRC you have a compressor fridge, should really have gone with
gas. It'll need to operate to a greater or lesser extent even in winter,
greater if the van interior is heated, via woodburner or gas heating.
As you are intending to stay put for weeks at a time it doesn't
make much economic sense in driving the truck just to charge leisure
batteries, 1 hour running = £5 in fuel.
I hate to say it but this strikes me as a situation where a generator as
a regular battery boost charge (say every 3 or 4 days)and as back up
makes sense.