Fridge - Economical requiring only solar?

[Martin CC O'Beirne]

Ello folks

 

My 3 way electrolux has been patched up several times over the years - I think its time to replace

 

I'm a ccer - Usings 12v for the fridge was always too heavy a drain even with 3 80w solar panels so I used Gas - I was happy enough with this set up - The aim though would be renewable energy solar or wind for all except the darkest months - I sometimes watch a film, use some LED lights and my rad is powered by a pump - I would say i'm a fairly light user but the fridge is one step too far for my set up, I want to avoid running the engine all the time.

 

Does anyone have a set up that works well - Solar maybe wind - A very economical fridge they would recommend?

 

Cheers!

 

Martin

 

 

[ditchcrawler]

No way can you hope to run a 3 way fridge on 12 volts they are just far to hunger. You need a compressor fridge if you want to run it from your batteries

[Phil Ambrose]

Brian is spot on, you will need to get something like a Shoreline fridge, using one is doable with solar. I have a 110ltre under counter fridge and a 80ltr under counter freezer which run quite happily from my 300watt PV arrey.

But I only cruise in the warmer sunnier months, during the winter I stay tucked up in my marina berth on hook up. From what I have read on here you will struggle during the winter unless you have a large PV array and running the engine will still be necessary.

Phil

[MtB]

I have a compressor fridge which I run 24/7 from 2 x 80w solar panels most of the year. For the darkest four months the panels are inadequate but the rest of the year they are fine and I never need to run the genny or engine.

 

The darkest four months are also the coldest during which the fridge is not really needed.

 

MtB

[Paul C]

This recent thread is along very similar lines:

 

http://www.canalworld.net/forums/index.php?showtopic=75669&hl=

[Naughty Cal]

Has to be a compressor fridge to be economical.

 

We have one of these.

 

http://www.mps-trading.co.uk/engel-sb47f-12v-upright-fridge%2Ffreezer~72

 

Not cheap but doesnt use a lot of power (0.5-2.5 amps max).

 

Not a massive fridge but it is fine for what we need. They do a bigger one with a bigger freezer here:

 

http://www.mps-trading.co.uk/engel-sd90f-12%2F24v-fridge%2Ffreezer~144

 

But that carries an even more scary price tag!

[ditchcrawler]

Has to be a compressor fridge to be economical.

 

We have one of these.

 

http://www.mps-trading.co.uk/engel-sb47f-12v-upright-fridge%2Ffreezer~72

 

Not cheap but doesnt use a lot of power (0.5-2.5 amps max).

 

Not a massive fridge but it is fine for what we need. They do a bigger one with a bigger freezer here:

 

http://www.mps-trading.co.uk/engel-sd90f-12%2F24v-fridge%2Ffreezer~144

 

But that carries an even more scary price tag!

I wonder how they get the variable load on that, does the compressor run all the time and they use an unloading valve by any chance and does the Turbo fan cool the condenser or move the cold air inside the fridge?

[Naughty Cal]

I wonder how they get the variable load on that, does the compressor run all the time and they use an unloading valve by any chance and does the Turbo fan cool the condenser or move the cold air inside the fridge?

The compressor only runs when needed not constantly.

 

The fan cools the condenser.

[ditchcrawler]

The compressor only runs when needed not constantly.

 

The fan cools the condenser.

Ta, just leaves the variable current consumption unless the upper figure is with the compressor running and the lower just the fan.

[Theo]

I have an A+ cheapo 230V fridge from Curry's. We left it on for a couple of days last week while we left the boat. The batteries were 1% higher (630Ah battery bank) when we came back. We have a 240Wp solar array mounted flat and a Tracer MPPT controller. The 3000W pure sine wave inverter has a quiescent current of 1.5A.

 

I was really chuffed. Specially as it's only April.

 

N

Edited May 1, 2015 by Theo

[MoominPapa]

Equivalent numbers to Theo's. 175W solar, Bosch A+ 240v fridge, chinese MPPT controller. Inverter in "power save" mode, where it tests the load every second and only starts up when loaded. Left the boat for 2 days with nothing else on, and batteries about 15Ah better charged when we returned than when we left. Having enough solar to be able to run the fridge indefinitely when the boat unattended is really useful.

 

MP.

[Martin CC O'Beirne]

great advice thanks - I'm trying to get my head round this - I'm moving from being a boat bachelor to a family of up to 4 - I need a different set up - I would also would like a washing machine - which introduces a whole load more stuff to work out

 

I think the 12v compressor fridges are just toooo expensive - 700 quid and that's a new small relatively cheap one

 

Washing machines of the commonly selected boat variety the 3.5kg drum ones are also pricey at 500 odd quid and id prob have to use it twice as much

 

A decent Honda generator ample for a washing machine - add a grand or so on top!

 

So I'm thinking conventional fridge, conventional washing machine & new inverter - another solar panel & battery maybe?

 

 

I'm not familiar with the maths that I need to do - What I have currently are 3 105ah bosch leisure batts about a year old. 3 80 watt solar panels. a small inverter that obvs need replacing. A small alternator which I think is a 50 if memory serves (prob doesn't :/)

 

Do you think I have any chance (with big enough inverter of what 2kw?) of running a conventional washing machine & conventional fridge for what 9 months of year - based on that set up?

 

What inverters would you recommend - A gather it has to be psw

 

Thanks folks!!

[Martin CC O'Beirne]

Hi Moomin papa - that inverter sounds good, does the fan turn itself off at night?

 

Cheers!

[ditchcrawler]

The fan on my inverter never runs unless I put a big load like a kettle on. I think you will need more than a 2Kw inverter to run a washing machine but I will let others who use them to tell you what is actually required.

[MoominPapa]

Hi Moomin papa - that inverter sounds good, does the fan turn itself off at night?

 

Cheers!

As Ditchcrawler says, the fan doesn't run unless there's a big enough load on. The inverter we have has a bit of a design fault - the fan its triggered by a very short term heavy load, like the start-up surge for the fridge. This means that every time the fridge starts up, the inverter fan starts too, only switch off again 30 seconds later when the inverter works out that the steady-state load from the fridge is well below the threshold needing the fan to be on.

 

Most high-ish power inverters these days have something similar to the power save feature, I think. Ours is Xantrex Prosine, and well over a decade old.

 

MP.

 

ETA our invertor is 1800W, and runs a Zanussi studio-size washing machine fine. The water heater element in the washing machine is 1500W. The design philosophy for the installaton is to make the inverter big enough to compensate for the smallish alternator on our chuggy engine, and an even smaller generator. Neither of these is powerful enough to run the washing machine, but either will replace the energy taken out of the batteries by the heating element running for 10 minutes or so during the course of a complete wash cycle.

Edited May 1, 2015 by MoominPapa

[spadefoot]

The fan on my inverter never runs unless I put a big load like a kettle on. I think you will need more than a 2Kw inverter to run a washing machine but I will let others who use them to tell you what is actually required.

I imagine that you'd also have to run the engine whilst using the washing machine, but others who use such a set-up will know better than I.

[Theo]

I imagine that you'd also have to run the engine whilst using the washing machine, but others who use such a set-up will know better than I.

On our Zannussi we choose always to wash using a 20degC wash. I feed the machine with hot water from the calorifier through a safety mixer. Once the first fill is over we turn the mixer to cold for the rinses. In this way the machine never draws current for heating and the inverter and batteries cope perfactly well even when moored up with the engine stopped.

 

N

[smileypete]

Sound like a reasonably decent PSW inverter with lowish standby current or 'power save' mode is the way to go.

 

Then A+ or better mains fridge and adequate solar for summer, add more solar in autumn to delay routine engine/genny running as long as poss.

 

cheers, Pete.

~smpt~

Edited May 4, 2015 by smileypete

[b0atman]

I have a 12v larder fridge that uses casing to cool hot gas presumably to stop inside from icing up its rubbish very greedy with amps unlike the freezer which has a heat exchanger at the back .

I think that I may go 240v and with money saved add more solar panels.

[Martin CC O'Beirne]

I have the Liebherr A+++ - looking good so far - I noticed a 0.09V drop when I first turned it on - 3 80watt solar panels appear to be giving me enough still but suspect as smiley pete says an extra panel in autumn may be required - thanks to all for advice on this

 

Ta

Martin