Off-the-Grid: How Many Watts Does a Refrigerator Use?
Refrigerators and freezers are used for preserving the food, cooling down beverages, and for other similar tasks. When the mains power is gone, refrigerators and freezers stop, with all the stored food and drinks being in jeopardy.
Regardless if You have a fridge that you want to keep operational during a power outage or you want to have a fridge or freezer running when camping, it is vital to know the power and energy requirements of your unit.
Refrigerator/Freezer Power: Starting vs Running Watts
Refrigerators and freezers are powered by electric motors that require more power when starting (hence 'starting watts').
Actual power requirements differ greatly depending on the refrigerator/freezer size, energy class, temperature difference, and similar.
Older larger units required up to 700-1000 running watts and 2000-3000 watts when starting.
If You have a large home refrigerator/freezer that requires 500+ watts, check its energy star rating - buying a new, energy more efficient unit may lead to great energy (and money) saving over a certain period of time. We say 'certain period of time' since this period depends on local electric energy prices, power difference between units, etc.
Modern refrigerator/freezer typically require:
- large home refrigerator: 200-400 running watts, 1000-1200 starting watts,
- average home refrigerator: 100-250 running watts, 700-1000 starting watts,
- small home refrigerator: 75-150 running watts, 400-600 starting watts,
- compact home/RV refrigerators: 40-50 running watts, 80-120 starting watts.
Note: the best method of finding out the actual power requirements of your unit is to locate and check a small plate on the back of the unit with its power requirements.
Off-the-Grid: How to Power Refrigerator/Freezer
The simplest way of powering a refrigerator during a power outage is to connect it to a strong enough portable power station.
Portable power stations feature builtin lithium batteries and power inverters and often come with 1-2 110V AC ports, combined with USB charging ports.
Depending on the size and energy class of the refrigerator, a 500W portable power station that stores at least 500Wh of energy is enough to power a 250W home fridge (or any similar device) up to ~1h and 35 minutes, while a 1000W portable power station with 1000Wh of stored energy can power 250W appliance up to 3 hours easily.
Note: Power stations usually feature an efficiency of ~80%, but are practically always advertised using 'raw' energy stored in the built-in battery. Also, depending on the fridge use and temperature difference, its electric motor may operate constantly, but also On/Off with Off period being often much longer than the On period - in that case, such portable power stations may power such appliances for much longer periods of time.
A great feature of power stations is that they don't release dangerous fumes and can operate indoors.
Another similar solution is the use of large deep-cycle batteries (AGM, Gel-Cell, wet/flooded, lithium-ion, etc.) and the power inverter.
Depending on the size of the battery (or battery pack) and the output power of the power inverter, such combinations may be used to power several home appliances for longer.
For example, 2x 200Ah 12V batteries connected in series (24 volts), with 1000W pure sine wave power inverter, are able to power 250W refrigerator for 14-15 hours constantly - again, it depends on the battery chemistry and the efficiency of the power inverter.
Another solution that stores energy in the form of fossil fuel are portable power generators.
Note: Portable power generators MUST NOT be used indoors, since they emit dangerous and toxic fumes.
The most popular class of portable power generators are 2000W power generators. Most of these units can operate at 25% power (400-500 watts) up to 10-12 hours.
During this period, the 2000W power generator operating at 25% (500W) can power 250 watts refrigerator constantly and charge 12V battery (or battery pack) with ~15-17 Amps.
Again, portable power generators release carbon-monoxide and other fumes that can kill humans and animals easily. This is a serious warning - never operate a power generator indoors!
Long Story Short: If You wonder how much watts does your refrigerator uses, check its label on the back or perhaps the manual. Modern, high efficient units often require just a fraction of power and energy that was required by the units 10-15 years ago.
When the mains power is not present, having a working refrigerator is very important for several reasons, especially if the refrigerator or the freezer is full of food that must be preserved for a longer period of time.
In such situations, a working fridge, combined with a TV and microwave oven, can be a real morale booster and a life saver.