Off-Grid Refrigeration Options
By LaMar Alexander
Simple Solar Homesteading
I have been off-grid for over 15 years and live in a 14×14 solar and wind powered cabin I built. 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 and one of the biggest problems off-gridders run into is how to have refrigeration without having a big 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.
I have used many different fridges in my off-grid adventures trying to find the lowest power use and factoring in convenience and food storage space and these are the options with the pros and cons.
If you can get a well-insulated ice box (cooler) or add extra foamboard 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, wet soggy food, has to be drained and restocked with ice, and ice may not be available and food does not stay at an even temperature so more spoilage.
Propane fridges are commonly used in RV campers and off-grid houses and some are 3 way meaning they can run off propane, AC or DC current. Propane fridges are generally good at keeping food cold and froze 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 are they take propane which might be expensive and unavailable, they may produce odors, they 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.
These 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. They are used mainly by truck drivers for keeping snacks fresh but can be used in off-grid situations. The pros are they use low power and can be run off a small solar electric system. The cons are not much food storage space, temperature will only get 30 degrees below room temperature so more food spoilage will not freeze food, may drain batteries without a control unit installed.