Electric or Gas Refrigerator?

When you are setting up a house to run off the grid (no mains power available) we are often told to buy a gas refrigerator as that will save on power.

But is it cost effective?

Our experience has been that it is not.

Doing what we thought was the "right thing" we started off with a second hand gas (propane) frig.

It sprang a leak, and we were told that it was unfixable, so we bought a new one of a brand that they said they could "fix". Within three years or so, it too sprang a leak. So we inquired about getting it "fixed", and was told it was about the same cost as buying a new one - which are not cheap, at least in this part of the world.

We had to do something in a hurry.

It came down to this "we can not make propane, but we can make electricity". The other factor was that we could buy three new electric refrigerators for the price of one new gas one.

So we bought a new electric refrigerator - and haven't looked back since.

Some of the factors.

I can understand why some of the books from years ago suggest buying a gas or kerosene refrigerator, as a refrigerator pulls a lot of electricity, and may need a factor of 10 for a few seconds to get it started. This means that you need an inverter that can handle an overload situation for a few seconds. In rough terms, if the frig is rated at 100 watts, then the inverter has to be able to handle a 1000 watts overload on startup. Once started it will drop back to near its rated capacity.

Most modern inverters that say they are suitable for refrigerators will have this "peak power" built in. Some old or small inverters can't handle the extra load.

So an absolute - you need the right type of inverter. Ours is a 3500 watt OutBack, and barely blinks when the frig starts up. To start, it pulls 40 amps for a second, and then runs on about 8 amps (at 24 volts).

Over the six months of Summer, if the sun is out, the solar panels will supply all the power we need, so there are going to be many days when the frig runs for free. However, during Winter, the frig does add an extra load to the generator - which is used to pick up the slack between the panels and wind generators and the batteries.

But do the sums.

In Australia, as petrol prices went up, so did the cost for propane. A 45 KG bottle now cost more than A$100, and running the gas stove and a gas refrigerator,a bottle will only last about 7 weeks. Just running the stove, a bottle lasts about 5 months. So every 7 weeks we were up for $100 - Summer and Winter. Now we are only up for more petrol for the generator when the wind doesn't blow and the sun doesn't shine.

In rough terms, running a gas frig we had to buy 7 bottles of propane a year. Just running the gas stove, we have to buy 2 bottles a year. Our savings on 5 bottles of gas (in the order of $500) more than off-sets the extra fuel to run the electric refrigerator.

The big plus.

We bought a LG  model GN-346FW (4.5 star rating). Remember, we had to buy in a hurry, so there may be better available, but we are very happy with it. It is frost free and fan circulated. You might think that running two fans is using extra power (and it probably is) but the fans pull the temperature down quickly so the frig does not run as long. And everything is beautifully cold. Plus, the freezer is bigger than a gas frig.

With a gas frig you have to manually defrost it.

Electric wins.

We are now glad that we were forced into making a quick decision.

Yes, gas refrigerators do work, and much better than nothing. However, their fuel needs to be cheap, and you have to be prepared to "fuss" with them, and have a spare bottle of gas on standby. We had to install an automatic change over unit. Otherwise, if you have to go away for a day, and the gas runs out as you leave, you come home to defrosted food.

If you are thinking of going electric, invest in a suitable inverter, and consider two generators. A beefy one (5000 watts plus) to bulk up the batteries, and a smaller one to top them up. In our case the smaller one is a 5hp engine running a 12 volt alternator modified to charge 24 volts.

There are a lot of factors to consider, but do not take it for granted that gas refrigerators will save you money. In our case they didn't.

Bob Orchard  Oct 2012.