Solar in Winter?

StephDeLux

StephDeLux

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Hi

Been reading the thread about the best accessory you have bought.

One thing that comes up often is solar. That puzzles me a bit because the experience I have with a 110W panel is that it's brilliant from mid-May to mid-September give or take and pretty useless between mid-October and April.

But, unless one has a 12V fridge, it is in Winter that we need the most electricity, not in Summer. With our way of travelling, we move with the van just about every day so I can't see us needing more than what the battery can give, certainly in Summer. And if we do stay static for a few days, it will definitely be with EHU.

Am I missing something?

Stéphane
 
they work really good in winter.
but you might have to drive down to southern spain and cross to morocco.
you can be fully charged and wasting solar power by 11 in the morning.
never had ehu.
but do run a lead into the house in summer off the inverter and power fridge and freezer etc in the house.
mind do have a bit more solar on my trailer roof . 6x80wt
.my first 3 panels i bought second hand in morocco in 2002 , they were about 10yrs old then ,still work ok.
the other 3 panels i bought in 2010 they were new , do give a bit extra power. solar is really cheap these day compared to twenty years ago.
 
vwalan said:
they work really good in winter.
but you might have to drive down to southern spain and cross to morocco.
Click to expand...

Thanks but... I mean... Winter in Morocco is like Summer over here :D

In a way, you confirm my thoughts :)
 
I don't think youer missing anything..
Flat mounted solar panels wont do much throughout most of the winter months ..
An mppt controler will help extract the max available ..and at least double the capacity of pannels you have... ie 200 to 300w will usually produce something..
Andy..
 
if staying in uk best get some lunar panels .
they have been around for years . if i remember correct jim put a good bit of info about them on here years ago.

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110watts isn't much, I've got 300 watts even that is not much cop in winter you need at least 600 watts. Even then you would struggle in northern Europe
 
My thoughts exactly. Won't get any solar then. Would be useless for us. We'll start with what comes with the van. If the battery proves insufficient it will be either a second one or one lithium. Or two. It was my thought for quite a while, but was just wondering after so many high praises for solar. If it is people who go to enjoy winter in the South (I would too!), then I understand.
 
there was years ago folk doing high output alternators for campers etc . dont know if there still is . they worked sort of ok.
mind depends on how much power you need.
many in winter and down south are powering fridges freezers washing machines dryers etc just like being at home.
no need for campsites and ehu.
i do have a generator but only use it to power welding etc in emergency times .
mind gas caravan lights are far better than leccy ones led etc.
lights and a bit of heat . plus they help keep mozzies away.

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*Machzoneman* said:
Fitting LED light bulbs is one of the best way to reduce energy consumption in Motorhomes and caravans.
Click to expand...

Thanks. It's going to be brand new, so full LED from the start :)

I think LED lighting has indeed radically changed the need for extra battery capacity.

Where I'll probably be short with just one lead acid battery is in winter in the Alps, where the heating air blower is probably going to use more than I anticipate.
 
This has been debated before, it depends entirely on your 12v needs as to what's 'enough'.

We go away in February in the UK, our 100w panel keeps our 75ah battery going with enough to keep our rechargeable appliances fully charged, plus the usual motorhome stuff.

No TV, but do watch DVDs on the laptop.
 
Stephane Bosman said:
Thanks. It's going to be brand new, so full LED from the start :)

I think LED lighting has indeed radically changed the need for extra battery capacity.

Where I'll probably be short with just one lead acid battery is in winter in the Alps, where the heating air blower is probably going to use more than I anticipate.
Click to expand...
I doubt you will cope in winter. It isn't just the low sun angle but the short daylight. You will have lights and heating on more than 12 hours a day.
If you plan on being away from mains power you will need a generator if adding a lot of solar panels isn't an option for some reason.

But, if you are moving every day consider a battery to battery charger, which could recharge your battery in an hour or so. :)
 
DBK said:
But, if you are moving every day consider a battery to battery charger, which could recharge your battery in an hour or so. :)
Click to expand...

If, according to current plan, we go for a Mercedes-based Hymer, the B2B charger is standard. My current thinking is that should charge one or two lithium batteries pretty quickly. But we'll see.
 
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I made our panel capable of tilting.
IMAG1005.jpg


In winter, what would be 2 amps flat, goes up to about 7 amps tilted ?

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Stephane Bosman said:
I think LED lighting has indeed radically changed the need for extra battery capacity.
Click to expand...
May have done 10 years ago but with all the fancy lighting in modern vans it doesn't work. I know you don't have to use them all but because they are there we use them.
With all the other electrics in the shoulder seasons we use 30-35a/h a day.
 
Richard and Ann said:
I made our panel capable of tilting.
View attachment 326567

In winter, what would be 2 amps flat, goes up to about 7 amps tilted ?
Click to expand...

Damn, that's a clean roof!! Guess I'll have to clean mine soon. ?
I also turned one of our panels into a tilting one, we usually park with hab door facing South, so get pretty good results.

20190824_100509.jpg


Note the dirt. ?

and I'm in the process of converting the Oyster into an 80w sun tracking panel with the help of a friend who's doing the tricky electronic control unit.....A really clever guy!

20190824_100521.jpg


The picture seems to have been squished, it should look taller than it is wide. ?
 
I tilt our 255watt panel in the winter used 4 old crutches as they’re adjustable, haven’t needed to use hook up to charge the batteries in a year or more since adding solar.
I’ve got an iPhone app called Simply Solar that tells me where to point and at what angle to tilt the panel for my location and time of year.
 
"Most people don't realize that solar panels produce more power in cold weather than in hot. This is because the system components have a negative temperature coefficient, which means they experience less resistance and yield more power in cold temperatures."

Of course the above statement from a solar energy research team does not say if the extra output can override the downside of shorter days and lower sun angle (the last being overcome by having a panel you can tilt.

Solar panels have come a long way in a very short time not least in becoming more affordable I do know that in the early days scientist developing this technology were at a loss as to why a tried and tested method of producing power in the arctic was not working any where near as efficiently in other areas , they obviously very quickly realised it was temperature difference.

How that effects todays modern panels i'm not sure not been able to find any reliable figures.

I have very little power use in my van I use a thermo electric fan to spread the heat around the van and all lighting is LED and most water we use comes from our 10litre drinking supply using the water pump as little as possible (people don't realise your water pump nearly 8 amps is probably your biggest power draw)(y)
 
Why hasn't anyone combined the solar panel with the vacuum tube type solar water heaters?
If heat is the enemy of solar panels, why not take that heat away and turn it into hot water?

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For pure 12v and 2x95ah leisure batteries, if you had to choose between a good B2B or 120w solar panel with MPPT controller as initial investment on a new van, which would you go for and why?

This is my current dilemma, hence seeking your input.

Cards on table, I’m currently leaning towards B2B as motorhome is not in storage without EHU.
 
if you use EHU in most of your camping spots then solar is pretty much useless.
If you are off grid then the only way to recharge is to start the van without solar.
It depends entirely on your circumstances as to which FITS best. One is no better than the other in the wrong environment.
 
on the other side of the coin B2B charger fitted later on is just wires and finding a location for it..
Solar means drilling the roof, removing interior panelling and dropping wires down somewhere hidden..
If I was doing ONE first from new, it would be solar for me so that it was done from factory.
 
My logic, admittedly potentially flawed, is that the B2B removes reliance on seasonal charging effectiveness, I need only diesel. Should I need more electrical juice, I simply (and considerately) run the engine for a while, whether that is whilst traveling or stationary.

It also avoids more holes in the roof...

Edit: van is from stock so no factory fit option for solar.

I think the B2B investment then also future proofs me for lithium batteries later on.
 
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We have 250 watts on the roof but for low angle sunlight over the winter months we then carry a 100 watt watt semi flexible on a long lead that we can angle towards the sun at any position around the van to help top up the batteries.

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(people don't realise your water pump nearly 8 amps is probably your biggest power draw) sorry hate to say this but that’s only 0.13333 amps per minute , how long do you run the pump, if I am misinformed please tell me , ? ?
 
I fitted a Victron battery monitor at the beginning of this year so I could keep an eye on my 100Ah battery. It's got a shunt to measure current as well as voltage, so it can see the amount of power that is being used and estimate the energy that's left. I was pretty convinced that I'd need a second battery for our tour of Europe that lasted from February to July.

In all that time, the Victron app shows my deepest discharge was 15Ah! Now we are low users, we run a low power laptop and various USB gadgets, no TV, LED lighting and a 3 way fridge... but wow! That includes northern Spain up in the hills where it was freezing overnight and sun rise was way after 9am, so we had the heating on low overnight and higher for a couple of hours before we got going. I massively overestimated that amount of power I'd be using and I don't need to waste 25kg and £££ on a second battery.

Now I have got a 260w solar panel with an MPPT invertor, but in February the sun was low, so it wasn't producing a hell of a lot. But even on the worst days the solar had topped it up before 11am. We were plugging in EHU on sites about 1 day in 3. But I was finding that my battery charger was going virtually unused because the battery was always already full anyway.
 
Servo said:
(people don't realise your water pump nearly 8 amps is probably your biggest power draw) sorry hate to say this but that’s only 0.13333 amps per minute , how long do you run the pump, if I am misinformed please tell me , ? ?
Click to expand...
Are you confusing amp hours here or something because if you have a current drawing device, namely a water pump that is drawing 8 amps then it is drawing 8 amps the instant you turn it on.
but to get waaay to technical here, amps draw in the context of "seconds" in time, you need to use coulombs (charge carried by amp over one second)
 
Feel free to give me the true usage per second I can then X by 60 ? ? for the minute rate ?
 
Constant, instantaneous and average current ARE expressed in amps...
8 amps is 8 amps.. not 8 divided by some division of time.

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