Solar/fridge query

[Herbenny]

We are finally getting our solar done.
I was given two options of 100 w and 150 w obviously difference in price. our fridge runs off our battery so if I was going to go 150 watt as I feel it's way more than what we need anyway.
My question is would I be able to leave my fridge running all the time even when parked up ?

 

[silverweed]

That’s a big question as there are lots of variables anyway such as size of fridge but mainly what season and where you are parked let alone the sum involved even if the solar was large enough. I mean electrical calculations and not money

 

[trevskoda]

Min id say would be 200w of panels and two 110 ah battery bank which should hold over night,but even at that you are on the fringe,double the above would be a better bet.

 

[Herbenny]

It doesn't matter how many ways this solar thing has been explained to me I can't seem to get my head around it, it all seems so technical
I just thought as I would have power that I could leave things running/charging in between trips but of course your right lots depends on light/weather etc and the tree we park by won't help it's cause either.
I suppose it will all become clearer once it's fitted and installed.?

 

[jagmanx]

Once a fridge is cold

It does not use much power to remain cold.
Assuming no opening and closing too much or worse adding warm items.

Maybe go for at least a 150W Panel maybe 200W the cost of the panel is worth it..solar is quite cheap these days

Fridge will get a bit warm in the morning (breakfast) but I suggest even if only moderately sunny you battery (ies) will be fully charged again by midday.
Little drain until you start opening the fridge again teatime/ evening meal...But is is either cooler then OR if it is hotter your solar will "do its job

I monitor my LB with a simple Voltmeter.
I appreciate this is NOT as good as a "charge meter" but it works for us
Adding a second LB is also good and will make use of a more powerful panel.

Get some details about the power your fridge uses (preferably how many AMPS it draws on 12V supply
A) When cooling and how long it might take to reach operating temp
B) when just ticking over

 

[Wooie1958]

If you can afford the 150w then get that :hammer:

 

[trevskoda]

My 200w roof panels only put back a few amps in mid winter at mid day.

 

[yorkslass]

Hi Jac,

I don't have personal experience of that kind of fridge, but i have done a bit of reading,

When in the van, it seems to be best to turn off the fridge overnight. It will keep cool cos it's not being opened.

Don't think it will work well in winter on your drive and with your solar obscured by trees.

 

[molly 2]

What consumption dose your fridge use ,some members run compressor fridges 24 7 but have 400w solar .

 

[edina]

I have a 175w panel with 2 Trojan T125 batts and I can leave my Waeco comp fridge running full time.
My advice would be to get the most solar you can fit on your roof.

 

[mistericeman]

We have 2 x 100w solar panels and Durite VSR charging 3 x 100ah leisure batteries....
Our Waeco 40l compressor type coolbox has been running none stop 24/7 /365 for nearly 3 years....
Only needing external charging in the depths of winter (when weather has been too wet and dismal for several weekends to bother heading away)
Obvs solar does little in UK winter so durite shoulders the bourdon on trips.

 

[Ed on Toast]

I have 300 w (2x 150w panels) feeding 3 x carbon gel batteries.

I am considering a fridge freezer (under counter 5 cublic feet type) with a freezer of about half that size on top.

I spend all year, out n about. Would a modern conderser type F/F run off my solar, all year, with the occasional alternater input to the batteries.

You good advise and guidance, most welcome.

Any make models advice also welcome.

Thanks

Ed

:egg:

 

[r4dent]

My question is would I be able to leave my fridge running all the time even when parked up ?

I assume you have a 12v compressor fridge. If you have an absorption fridge forget the idea of running on 12v full time.

The first question is how much power do you use?
A typical 12v compressor uses 500 – 600 watt per day.
Therefore, to run your fridge for 24 hours you need battery capacity of 600 watt hours = 600/12 amp hours (ah)=50ah.
In practice you only get to use about half the battery's capacity, therefore a 100 ah battery will be sufficient to power the fridge for 24 hours, but add in the power for other hings (lights/ TV/ water pump) it is getting very tight. I suggest that 2 x 100ah batteries is the minimum.

The next question is will the solar panel provide enough power each day to recharge the batteries?
On a UK winters day a 150 w panel will provide about 150w each day, on a UK summers day about 900w and on a beautiful day on the Costa Brave about 1500w. For a 100w panel the figures are 100w / 600w / 1000w. Remember the fridge uses 600w a day, plus some for TV etc.. For a 100w panel the figures are 100w / 600w / 1000w. So for UK use get a 150w panel.

So my answer is get a 200ah+ battery bank and a 150w panel.
This gives you:-in UK winter a max of 2 overnights; in UK summer keep an eye on the battery and be prepared to move on if the weather is bad ; Spanish summer you’ll be OK indefinitely.

 

[Ed on Toast]

So, with my set up, a fridge freezer? and if so, where can i look on the internet for suitable fridge freezer, within my generation range?

Many thanks again

Ed

:egg:

 

[n brown]

never mind all that technical stuff, why would you need to leave it on? turn it off at night and when it's not being used, and run it off EHU when you can. i don't understand this reliance in fridges , there's shops everywhere, we buy fresh and use it. if we have a glut of something , then a bag of supermarket ice will usually sort it

 

[r4dent]

never mind all that technical stuff,

"all that technical stuff" was an attempt to help a fellow member who wants to use his fridge whilst wild camping so no EHU. You camp your way and he'll camp his. Please do not criticize people who want different things to you or those who try to help them.


We have enough outside people saying what we can and cannot do, lets not be divisive within the group.

why would you need to leave it on? turn it off at night and when it's not being used, .

Most fridges turn them self off at night because the fridge is cold enough. But if you do turn it off at night it may be a little warmer in the morning and use extra power to cool it down, so no real reduction in power consumption. Turning a fridge off at night is, in practical terms, pointless.

... and run it off EHU when you can.

Most 12v fridges are just that ...12v so using they can't run on EHU. The battery charger would, of course, run on 240v but if he has sufficient Solar the EHU isn't needed.

Like I said this is about compression fridges, the use of absorption fridges is a different ball game.

 

[Ed on Toast]

Thanks NB for the additional options but I can't even remember the last time i bothered with an EHU, it is so long ago.

I have thought long and hard about it and would love to have a small freezer topped fridge, that runs on solar.

I just do not currently know enough about it, so hence asking more knowledgeable folk on here.

I have an existing space that is 20" wide and 52" high that I am hoping, after some good advice and pointers from folk here, will house a new combined Fridge Freezer.

This will mean my gas compsumption will be then only the Hob and BBQ point.

I have a underslung tank, so my gas is cheap enough, so it is not really a cost based change but to extend my 'Off Grid' time and also having a freezer that enables me to batch cook would be great. I am not wanting to just add a freezer unit to my existing three way fridge, that is an option i have considered and discounted.

Many thanks

Ed

:egg:

 

[Ed on Toast]

I am also considering adding a 12 volt and 240 volt immersion elements to my existing gas water heater for pre warming and or fast heating but I guess that is a whole new question to ask

Kind regards

Ed

:egg:

 

[Nabsim]

I am also considering adding a 12 volt and 240 volt immersion elements to my existing gas water heater for pre warming and or fast heating but I guess that is a whole new question to ask

Kind regards

Ed

:egg:

Ed we have a Waeco 110 compressor fridge and all heating is diesel which just leaves us with gas for hob and grill (BBQ when used as well). All through the summer we have had no problems with power from our 2 x 150W solar although I did increase leisure battery bank back to 270Ah. Our batteries are Powerframe 3 x 90ah. On our recent trip to Scotland everything was good from the Wednesday to the Monday without starting engine or EHU but by then we were starting to get low, the weather had been very bright with quite a bit of sun during the day. We moved from Moffat to Falkirk which isn't a long running time to charge as we have no B2B so batteries would not have been fully charged on arrival. We moved again next day but only a few miles across Falkirk and by the following morning we needed to get EHU. We were using the heating, our TV when we use it runs from its own rechargeable batteries so not draining overnight, we do charge phones, iPads, watches.

Booked a site on the Wednesday and we were on hookup approx 18 hours. Over the next days each of these places were a days travel: Tyndrum, Fort William, Mallaig. The weather was more what you expect in Winter overcast and dull predominantly with little sun but moved a bit each day. When we got up next day at Mallaig we needed EHU.

Ignoring what should happened and any figures in favour of what actually happened: If you get bright days in Winter it makes a massive difference, more than what I would have expected, If the weather is not good 300W of solar will give you a day and a half to 2 days before other power sources are needed.

The 110 fridge is bigger than you may think, it holds a massive amount of stuff, likewise the freezer box, this is because it is much deeper than a 3 way fridge so more internal space, yes 110 litres is the same anywhere but so much more usable space for the box size. For just you I would think a unit half this size would be plenty. Our 110 is rated at 45amps per day if that helps.

I am looking at what options will actually suit us but its not black and white for anything we have looked in to so far. We dont want to use hookup and more often than we will need to empty cassettes and take on water, do washing etc so ideally no more often that every 4 days. We would prefer to just empty, fill, wash without needing EHU at all.

Bear in mind though the days are not at their shortest yet so what we got over the last couple of weeks is not sustainable through winter. Hope this helps you a bit in your research

 

[mistericeman]

If you are using 500 - 600 watts for the fridge, you also have to allow as much again for other power - lights, heating fans, charging phones, maybe a TV. So you are looking at 1000 watt hours a day. In summer, there is no problem, but in winter, although you can expect an average of one hour's full sunshine per day, that isn't what you get. Some days you get theree hours, some days you get none. And the sun is at a low angle, so your horizontal panel misses about half of it.

So using an average of 1000 watt hours a day, to get through four consecutive days of gloomy overcast weather (it happens!), you need a usable 4000 watt hours of battery storage. Assuming a 50% discharge at 12v, that means you need 666AH of batteries.

However, to recharge those batteries up from 50% you will need to put in 400AH at 13.8v, which means the input has to be 5,520 watt hours, meaning you need 2,760 watts of solar panels to be able to recharge in four average winter days (by which time the fridge and other loads will have used power again anyway, so you need a vast solar array)

So in summary, you really can't rely on solar panels to power a fridge in winter.

I use gas.

OR just move on each day in winter ....