Refrigerator/Solar

[Plymouth Sailor]

Hey Fellow Sailors,

I need advice on possible electrical options. I purchased an old boat two years ago but never tried the refrigeration. Did so yesterday with shore power and it works great. I’m going back to my mooring this year so shore power is a moot point. Is it at all possible to convert this from ac to a few solar panels? I know of people who’s refrigeration runs ice cold all summer on solar. It would be amazing to get to my boat and grab a cold beer without the need for ice. I’m pretty handy but my electrical knowledge is limited. Your constructive feedback appreciated!

Thanks,
Mark

 

[kappykaplan]

Please confirm the refrigeration runs on DC, not AC. If it runs on DC and your house battery bank is large enough to handle the load overnight, then solar is the way to go. I have a pair of 130 watt panels on my boat and they were more than sufficient for cruising with the Scouts in the summer months.

 

[Captain Larry-DH]

It would be amazing to get to my boat and grab a cold beer without the need for ice.

Yes indeed! Those will be the most expensive beers you ever buy.
Once you answer @kappykaplan ‘s questions we can offer some realistic advice. BTW whether it runs on AC or DC the next question is how many watts/amps it draws, and if it only runs on AC what type of inverter you have (if any). Also, house bank capacity and type of batteries.

 

[Plymouth Sailor]

Please confirm the refrigeration runs on DC, not AC. If it runs on DC and your house battery bank is large enough to handle the load overnight, then solar is the way to go. I have a pair of 130 watt panels on my boat and they were more than sufficient for cruising with the Scouts in the summer months.

I would imagine if it runs on shore power then it’s an AC ergo not convertible?

 

[dlochner]

I would imagine if it runs on shore power then it’s an AC ergo not convertible?

At least not easily and inexpensively.

 

[Davidasailor26]

If the refrigerator plugs into a 120V outlet and only runs that way on shore power it probably is AC. If it’s tied into the boat’s DC system it’s likely that it’s DC powered and just running off a battery charger that’s powered by the shore power.

If it’s AC powered and you really want to keep it running on a mooring an inverter might be less expensive than a conversion, although you’ll have some loss of efficiency there. You’ll need to find out how many watts the fridge draws when it’s running and what percentage of the time it generally runs. You can use that to figure out how many watt hours it consumes per day. Pad that by 10% or so for the inverter inefficiency. Divide that by about three to figure out roughly how many watts of solar you’d need to sustain the load.

Wiring the inverter is not trivial - there are some considerations with fusing, cable size, and grounding, so take those into account if you’re going to install one.

 

[rgranger]

AC/DC are not your only choices…There are fridges that run off of propane…

https://www.amazon.com/SMETA-Portable-Propane-Refrigerator-fridge/dp/B085938N35/ref=asc_df_B085938N35/?tag=hyprod-20&linkCode=df0&hvadid=693634985194&hvpos=&hvnetw=g&hvrand=14821663330613895596&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9021656&hvtargid=pla-942516564660&psc=1&mcid=518884293cfe3c8b857bbc9a9412cd92&gad_source=1&gclid=EAIaIQobChMIzq3ersqEhgMVQirUAR2YFQY4EAQYAyABEgLCQfD_BwE

 

[Stu Jackson]

Sailorchic34's New Dorm Fridge - inverter driven dorm fridge
Sailorchic34's new Fridge - Cruisers & Sailing Forums

 

[Davidasailor26]

AC/DC are not your only choices…There are fridges that run off of propane…

https://www.amazon.com/SMETA-Portable-Propane-Refrigerator-fridge/dp/B085938N35/ref=asc_df_B085938N35/?tag=hyprod-20&linkCode=df0&hvadid=693634985194&hvpos=&hvnetw=g&hvrand=14821663330613895596&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9021656&hvtargid=pla-942516564660&psc=1&mcid=518884293cfe3c8b857bbc9a9412cd92&gad_source=1&gclid=EAIaIQobChMIzq3ersqEhgMVQirUAR2YFQY4EAQYAyABEgLCQfD_BwE

My grandparents had an RV with a propane / DC fridge, but as I remember it the propane could only be used if the RV was perfectly leveled. That doesn’t seem boat friendly unless that limitation’s been worked out over the years. I also wouldn’t be comfortable leaving a propane powered appliance running while the boat’s unattended.

 

[kappykaplan]

I also wouldn’t be comfortable leaving a propane powered appliance running while the boat’s unattended.

 

[sailme88]

ALL solar is DC. ALL shore power is AC. Shore side solar requires AC to power the inverter that creates AC from the DC. That being, if your fridge is AC you can invert to run it. But doing that is not efficient as the conversion carries a loss. Options: replace the AC fridge with a DC unit. Units designed for marine use will be less susceptible to corrosion and are built to withstand under volts that occur with a draining battery. AC units demand a constant power source. That's why residential systems fail in brown outs.

or you can invert and add several solar panels. Panels are rated by watts. You'll need to know the AC needs of your fridge in order to size the system..

 

[JBP-PA]

You can buy a decent portable DC fridge for about $200-$250. You can get a mini fridge big enough for a 6 pack for under $30.

 

[Plymouth Sailor]

At least not easily and inexpensively.

Another idea possibly: I have a converter of sorts that attaches via clamps to the battery and then has ac plugs on it where one could plug in a refrigerator. I would imagine that may draw way too much power even with solar panels however I may use refrigeration just while sitting on my boat. Any thoughts? Thanks!

 

[kappykaplan]

Do you have any photos of the refrigerator and where it plugs in?

 

[Plymouth Sailor]

Do you have any photos of the refrigerator and where it plugs in?

It has a standard 3 prong plug that you would find in your home which I plug into my shore power.

 

[Plymouth Sailor]

I also have a basic converter which attaches to a battery and then has a standard three prong plug I could use as ac however I would imagine that would drain the battery even with solar. Any thought guys?

 

[kappykaplan]

As others have pointed out, use of an inverter adds inefficiencies by converting DC to AC. More investigative work required on your part.

 

[rgranger]

Expensive inverters can get to 90+ efficiency but they are $pendy

6.5. Efficiency of Inverters | EME 812: Utility Solar Power and Concentration

.

 

[Tally Ho]

One of the best features on my O’Day 322 is the fridge! Cold beer and some sandwich stuff always on board.

Mine in an Adler-Barber unit in the icebox. It runs on 12-volt power, but the battery charger is always on when I am at the dock.

I can run it for a few days on battery power when I go on anchor for a long weekend. But I often put a frozen gallon jug of water in the fridge when out for a few days, and then I can turn the power off.m

A photo of what you have would be helpful, but it sounds like it just runs on A/C power…but if it is insulated pretty well, you can throw some ice in there and cold beer for a few days .

Greg

 

[east coaster]

I have an Adler Barbour 50 and it runs great especially since I changed its controller to the 500 series which switches it from AC to dc and back again without human intervention. On shore power it cools great and with the initial cooling done the dc takes over when I leave the dock. No inverter or other dodads involved. Also have 330 watts of solar to take care of things underway.