Off-Grid Refrigerator Options: DC vs Propane vs a Regular Fridge on Solar

An off-grid refrigerator is any fridge that can keep food cold without a utility connection. There are four practical ways to do it: a DC refrigerator that runs straight from a solar battery bank, a propane refrigerator that runs on a gas flame, a standard household fridge powered through an inverter, or a chest unit set as a refrigerator, which uses the least energy of all.

The right choice depends on how much solar and battery you have, whether you have propane on site, and how much you want to spend up front versus every month. Below is how each option works, what it costs to run, and when each one makes sense. One disclosure: we sell DC and AC solar refrigeration and the solar gear to power it, not propane fridges, so we will be straight about where propane is the better fit.

Off-grid refrigerator options at a glance

Option 1: DC refrigerators

A DC refrigerator uses a compressor that runs directly on 12V or 24V power from your battery bank. There is no inverter in the loop, so none of your stored energy is lost converting DC to AC, and there is no inverter idle draw running all night just to keep the fridge on. That is why DC models are the default choice for dedicated solar cabins.

Pros: very efficient, silent except for the compressor, no fuel to haul, and pairs cleanly with a 12V or 24V solar system.

Cons: higher price than a standard fridge, fewer sizes and styles, and the battery bank has to be sized to carry it overnight and through cloudy stretches.

To size the panels and battery for one, see how many solar panels it takes to run a refrigerator.

Option 2: Propane refrigerators

A propane refrigerator is an absorption fridge. Instead of a compressor, a small gas flame heats a sealed refrigerant loop, and that heat drives the cooling cycle. There are no moving parts in the cooling system, so they run silently, and they keep working whether or not the sun is out.

Fuel use is modest. Unique Appliances, a major off-grid propane fridge maker, rates its 10 cu ft standard model at approximately 1.4 lb of propane in a 24 hour period. At that rate a 20 lb tank lasts about two weeks, and a month of use is roughly 42 lb of propane, or about 10 gallons.

Pros: no solar or battery needed for cooling, quiet, and proven for decades in cabins and RVs.

Cons: an ongoing fuel cost, tanks to refill or a delivery to schedule, and a flame inside the house. Absorption fridges also need to sit level to work properly, and they cool more slowly than compressor fridges, especially in a hot room.

Safety: a propane fridge burns fuel indoors. Install it exactly as the manufacturer specifies for gas supply, clearances, and venting, have the gas line done by a qualified installer, and keep a working carbon monoxide alarm nearby.

Option 3: A standard fridge on solar

You can run an ordinary household refrigerator off grid. It plugs into a pure sine wave inverter, and the inverter draws from your battery bank. This is the cheapest fridge to buy and the easiest to replace, and it comes in every size and style.

The trade-off is energy. A modern full-size fridge is often rated somewhere around 300 to 600 kWh a year on its yellow EnergyGuide label, which works out to roughly 0.8 to 1.6 kWh a day, before inverter losses. Its compressor also pulls a startup surge, so the inverter has to be sized for that, and the inverter itself uses power just staying on around the clock.

Pros: low purchase price, any size or style, and simple if you already have a home battery system or a hybrid inverter that is on anyway.

Cons: the largest solar array and battery of the four options, an inverter that must stay on 24/7, and higher losses overall.

If you go this route, pick the most efficient model you can, check the kWh figure on the EnergyGuide label, and size the system from that number.

Option 4: A chest unit set as a refrigerator

This is the most efficient off-grid refrigerator option. A chest unit holds its cold because cold air sinks and stays inside when you lift the lid, and the thick insulation of a dedicated solar chest unit cuts energy use even further. SunStar chest units have a two-in-one thermostat, so you can set them as a refrigerator instead of a freezer.

Set as a refrigerator in a 77 degree F room, SunStar rates its units at:

• ST-8CF (8 cu ft, 12V/24V DC): about 145 Wh a day
• ST-15CF-AC (15 cu ft, 115V AC): about 190 Wh a day
• ST-21CF-AC (21 cu ft, 115V AC): about 240 Wh a day

That is a fraction of a typical upright fridge, so a 100 to 200 watt array and a single battery can carry one. The trade-off is convenience: you reach down into a chest instead of opening a door, so it helps to use baskets and keep things organized. Many off-grid homes run one chest unit as a freezer and a second as a fridge.

Which off-grid refrigerator should you choose?

• You have solar and want no ongoing fuel cost: a DC chest unit or a DC refrigerator. Lowest running cost and the smallest system for the cold storage you get.
• You have propane on site and limited sun or battery: a propane refrigerator is hard to beat, as long as you are comfortable with the fuel, the venting, and the refills.
• You already have a large home battery or hybrid inverter: a standard efficient fridge is the simplest path, since the inverter is running anyway.
• You are building a small system and want the most efficient option: a chest unit set as a refrigerator.

Off-grid refrigeration we carry

Every product below is carried by Krato Power and in stock as of this writing.

Most efficient DC option: SunStar ST-8CF 8 cu ft DC Chest Freezer/Refrigerator. Runs on 12V or 24V DC, rated at about 145 Wh a day as a refrigerator. $1,298.97.

Large DC option: SunStar ST-21CF 21 cu ft DC Chest Freezer/Refrigerator. SunStar's largest chest unit, on 12V or 24V DC. $2,298.97.

For homes with an inverter already running: SunStar ST-15CF-AC and ST-21CF-AC. Standard 115V plugs, rated at about 190 and 240 Wh a day as refrigerators. $1,598.97 and $2,198.97.

See them all in our solar refrigerators and freezers collection.

Power it

For a chest unit or a small fridge: Rich Solar RS-CK400 400W 12V Complete Solar Kit. Two 200W panels, a 40A MPPT charge controller, a 12V 100Ah lithium battery, and a 2,000W pure sine inverter. $1,679.99.

For a standard full-size fridge: Rich Solar RS-CK800 800W 12V Complete Solar Kit. Four 200W panels, a 60A MPPT charge controller, 200Ah of 12V lithium battery, and a 2,000W pure sine inverter. $2,869.99.

Building your own: MEGA 200 12V solar panels ($239.99 each), a BRAVO 40 MPPT charge controller ($159.99), and ALPHA 1 12V 100Ah LiFePO4 batteries ($499.99 each).

Frequently asked questions

Is there a refrigerator that doesn't need electricity? Yes. A propane absorption refrigerator cools with a gas flame and needs no electricity for cooling, though some models use a small amount of power for igniters or controls. Check the specific model.

What is the most efficient off-grid refrigerator? A chest unit built for solar and set as a refrigerator. SunStar rates its 8 cu ft DC chest unit at about 145 Wh a day as a refrigerator, far below a typical upright fridge.

Is propane or solar cheaper for an off-grid fridge? Propane is cheaper to start, since you do not need panels or batteries, but you pay for fuel every month. Solar costs more up front and almost nothing to run afterward. Over many years, solar usually comes out ahead if you have decent sun.

How long will a 100Ah battery run a 12V refrigerator? A 12V 100Ah LiFePO4 battery has about 1,150 usable watt-hours. A DC chest unit set as a refrigerator at about 145 Wh a day can run for roughly a week on it with no sun. A larger or less efficient fridge will run far less, so divide the usable watt-hours by your fridge's daily use.

Will a 400W solar panel run a fridge? In about 4 sun hours, 400 watts of panels make roughly 1,200 Wh a day after losses, enough for an efficient full-size fridge with a battery, or a chest unit with plenty to spare. See how many solar panels to run a refrigerator for the full sizing table.

Can I use an RV 3-way fridge in an off-grid cabin? Some people do. A 3-way fridge runs on propane, 120V AC, or 12V DC, but it is an absorption fridge on every mode, and the electric modes use a heating element that can draw a lot of power. On solar, it is usually best run on propane.

Not sure which way to go? Call our team at 888-855-7286 with how much solar and battery you have and how much cold storage you need, and we will help you choose and size it. For more, see our solar freezer guide.

Energy and fuel figures are manufacturer ratings and estimates. Actual use varies with model, room temperature, settings, and how often the fridge is opened. This guide is general information, not electrical or gas installation advice. Have electrical and gas work done by qualified installers per local code.

Reviewed by the Krato Power team. Questions? Reach us at 888-855-7286.