I have been off grid for over 15 years and live in a 14×14 solar and wind powered cabin I built. I have used many different refrigeration options in my off-grid adventures.
My current power system is 580 watts solar and a 400 watt wind turbine. I also occasionally use a small gas generator for running a washing machine or recharging the batteries on low sun days.
That is a typical off-grid setup like most off-gridders use. One of the biggest problems off-gridders run into is how to have refrigeration without a big power system. The average grid connected house fridge consumes 500-750 watts when running, but uses 1200-2000 watts to get the compressor pump started (cold crank power). That is way too much power for a small off-grid system and would require a minimum of 2kw of power just for the fridge.
In my years of trying to find the lowest power usage option and factoring in convenience and food storage space, these are the setups and these are the options with the pros and cons.
Best off grid refrigeration options
ICE BOX / COOLER
If you can get a well-insulated ice box (cooler) or add extra foam board insulation to an icebox, you can keep food fresh but not frozen for about 5 days. Some new cooler manufacturers claim 7-10 days but I am skeptical. If you have access to cheap ice this is probably the lowest cost solution.
The cooler will stay colder if you can keep it in the shade and add extra insulation. The pros are it is cheap and readily available and can be taken with you if you are camping. If you live in a cold climate, an ice box in winter is free to use and you can freeze your own ice.
The cons are it won’t keep food frozen, and food can easily get wet and soggy. Also, an ice box has to be regularly drained and restocked with ice, even when ice may not always be readily available. Food does not stay at an even temperature in a cooler, resulting in more spoilage than other options.
Propane refrigerators are commonly used in RV campers and off-grid houses. Some are 3 way, meaning they can run off propane, AC, or DC current.
Propane fridges are generally good at keeping food cold and frozen, and have more room for food storage. They do require some maintenance and some are vented or vent-free depending on the model.
The cons of propane fridges are they take propane which might be expensive and unavailable. They may produce odors, or have a pilot light which may go out. And if they break down they can be expensive to repair.
The Danby model propane fridge I had consumed almost 1 gallon of propane a day, which is why I stopped using it. But that may be different for other models and could be more or less.
Thermoelectric coolers are generally small cooler units that have a thermoelectric plate that runs off DC and will lower the temperature of the cooler to about 30 degrees below the room temperature.
These are used mainly by truck drivers for keeping snacks fresh, but can be used in off-grid situations.
The pros of thermoelectric coolers are they use low power and can be run off a small solar electric system.
The cons are they do not have much food storage space. Also, temperatures will only get 30 degrees below room temperature, so potentially more food spoilage. They will not freeze food and may drain batteries without a control unit installed.
CHEST FREEZER CONVERSIONS
A chest freezer can be converted to a fridge/freezer using a control unit that monitors the temperature in the chest and shuts off the power so it stays cold but not frozen.
This is a common off-grid application for making a fridge and if the temperature is set correctly you can keep frozen food on the bottom of the chest and food you do not want frozen on the top.
The pros are chest freezers are fairly inexpensive and they average under 2 amps when running. They also have good food storage space and fit into smaller houses.
The cons are it is a chest so finding the food on the bottom can be a hassle. They may require up to 1200 watts cold crank power to get running, and they develop condensation. Additionally, you have to buy a separate thermostat control unit.
For long term off-grid living, the chest freezer conversion is probably the most commonly used refrigeration system.
DANFOSS COMPRESSOR FRIDGE/FREEZERS
A Danfoss compressor is a multi-voltage compressor that can run on AC or DC. Because it does not have a separate compressor motor it uses very little power, and some use less than 1 amp when running. They can be found in Sundanzer chest freezers or smaller units like the ARB fridge/freezers.
They are a true zero degree freezer, and like a chest freezer, you can freeze food on the bottom and have unfrozen food stored on top.
The pros are they use very little power and can run for 2-3 days off of a standard 12 volt battery. They are smaller for small houses and they have few moving parts to break down. The ARB units are portable for off-grid and off-road use.
The cons are they generally have limited food storage space and they are much more expensive, averaging $1000 for a Sundanzer chest fridge and about $800 for an ARB fridge/freezer.
OFF GRID REFRIGERATION SUMMARY:
I have used all of these fridge types in my off grid house. For long term off-grid living I recommend a chest freezer conversion. But if you want super low power use and the convenience of a portable camping unit, the Danfoss compressor fridges are excellent. The durability and low power consumption offset the high cost.
I have many videos of my fridges over the years and all my cabin systems on youtube:
Please drop by my website to see my cabin and many new off-grid cabin designs:
Prepper News Watch for June 24, 2014 | The Preparedness Podcast
Tuesday 24th of June 2014
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