Every power outage I have lived through, regardless of the length of time, triggers an immediate question: Is my fridge going to stay cold enough? Though most power outages are short, lasting only a few minutes to a few hours, losing hundreds of dollars of food to a long-term blackout is unacceptable.
So, how can you keep your fridge cold without power? The most basic advice to keep your fridge cold is to keep the doors closed as much as possible. A fridge will stay cold for a few hours, and a freezer will stay cold for a few days without any prep. Placing duct tape over the door will keep your family from mindlessly opening the fridge and letting cool air out. For most blackouts, this is enough.
To survive a power outage that lasts for days or even weeks, you must plan for it. You might already have an emergency preparedness plan in place that had you stock up on lots of shelf-stable foods. Even so, letting a fridge and freezer full of food spoil is expensive, and in some cases, dangerous.
Some of the following ways to keep your fridge cold in the absence of power are doable on the fly, but most are certainly not. There are a few ways to keep your fridge cold during a power outage that won’t cost much to put in place. Plan if you need your solution to be cheap. Plan to spend money if you want your solution to be dependable.
Table of Contents
1. Insulate the Exterior of your Fridge
Collect any blankets, sleeping bags, or other insulating materials you have on hand and cover all sides of your fridge with them. Use towels to tightly pack the space between the bottom of the fridge and floor. Doing this will trap the cold air in your fridge and freezer, but only if you don’t need to go into it more than once a day.
Safety note: Make sure your fridge is unplugged if the power comes back on when you’re not home or sleeping.
This method works best on a combination fridge and freezer, as it allows the freezer to keep the fridge cool longer.
It can be done for no extra money and no real planning, assuming you have everything on hand. It works well short-term, but don’t expect your fridge to stay cold for more than a couple of days.
2. Use Frozen Ice Jugs or Bricks
This method can be done in several ways, but it can only really work if you have a chest freezer and extra space. It takes a little extra planning but has the added benefit of being a drinking water source.
Take several clean soda bottles, water jugs, or specialized water bricks and fill them about 90% full of drinking water. Tap water will work, but you can use filtered or other treated water if you like. Make sure to leave enough headspace for the water to expand as it freezes.
Place the jugs in layers at the bottom of your chest freezer, and then place your frozen foods on top.
When your power goes out, take a bottle from your freezer and place it on the top shelf of your fridge. Why keep your ice on the top shelf? Just as warm air rises in your house, keeping your basement cold, warm air rises to the top of your fridge.
This method takes some planning. It can be done on the cheap, depending on the container you choose to use. You can keep your fridge cold as long as you have frozen water bottles to put in your fridge.
3. Use Frozen Saltwater Bricks or Jugs
The saltwater ice method works better for keeping a fridge colder than with regular ice, although the water is not suitable for drinking after it thaws. If you have a stable water supply or have another water storage plan, freezing saltwater would be an excellent way to go.
When ice melts, it takes a lot of heat out of the air to transition from solid to liquid. While ice is still frozen, the heat in your fridge works toward melting the ice. This stops the air temperature from warming, at least until all of the ice has melted. That’s why a block of ice is so good at keeping the surrounding air cool.
Ice made of saltwater melts below freezing, which means that the freezer will stay at a cooler temperature as the ice melts.
As with regular water bottles or bricks, make sure to leave about 10% headspace in the bottle to allow for expansion.
4. Dry Ice
While dry ice can keep your fridge cold during a power outage, it comes with risks. Finding it in a blackout may be the number one issue. I worry more about the carbon dioxide vapors collecting in small spaces without proper ventilation. Other options are safer. Use this method at your own risk.
If you are aware of the risks and safe handling techniques, it may be an option. According to Continental Carbonic, you would need about 3 lbs per square foot of fridge space. Freezers would require much more.
To use, place your dry ice on a tray on the top shelf of your fridge so the cold gases can travel down over your food and keep it cool. Plan to replenish it daily from your supplier. Dry ice is tough to store in your home as it needs to be held at sub-zero temperatures to stay stable.
When opening your fridge, make sure you have lots of windows open for ventilation. Also, keep an eye on small children and pets, as they are a lot closer to the floor where CO2 will collect and displace oxygen.
5. An Inverter, Extension cords, and Your vehicle
This one can be tricky because your vehicle has to be running to power your fridge. This might be an issue for two reasons.
First, you need to be concerned about proper ventilation. If your car is in a garage, you will need to open the garage door a bit.
Second, there are concerns that it could harm your alternator. With that said, it’s pretty normal to see building contractors do this in the wild. I’ve seen this method used with portable table saws and other heavy-duty power tools. I’ve personally had to resort to this a few times to power my fish tank, and though I’ve never run a fridge, it’s never been a problem. Use this method at your own risk.
Third, your inverter must have a large capacity. Just how large? Capacity needs to exceed the electrical draw your fridge needs to start the compressor. Using too small an inverter might blow its fuses when the electrical demand is too much.
Essentially, you attach an inverter directly to your car’s battery and run an extension cord to your fridge. Your vehicle needs to be running, or else the battery will run out of juice quickly.
The upside? You only need to run your car and inverter until your fridge cools, and then only a few times a day to keep your food cold. That’s assuming you open the fridge door only when necessary.
6. An Inverter and a Deep Cycle Battery Bank
This method has some advantages and disadvantages over using your car and gasoline as a power source. Using deep cycle batteries will be more expensive than using an inverter with your vehicle. You will need enough battery power to run your fridge for an extended period. You will also need a power source to recharge the battery if it runs down, such as a generator. Theoretically, you could chain together enough batteries to run your fridge for months before needing a charge. The cost and the space to set them up, however, would be ridiculous.
Don’t look to car batteries for this solution. According to MK Battery, deep cycle batteries, such as marine or RV batteries, are designed to deliver a steady source of power for more than 50% of its full charge. Car batteries are different. They are designed to take a big power draw for a few seconds to start your car and then be charged back up immediately by your alternator.
Using a battery bank in tandem with a generator is a more efficient way to protect your fridge contents than using your car as your power source. You will only need to run your generator to charge the batteries while your fridge will run continuously.
After researching my fridge, I found that a single 200ah deep cycle battery should run my Samsung side-by-side refrigerator for about 15 hours before charging is required. Theoretically.
To see an example of a real-world DIY battery bank and inverter setup, see this detailed set of instructions at instructables.com.
7. Portable Gas-Powered Generators
As long as you have a safe outdoor space to run a gasoline generator, it will power your fridge during a power outage. If you live in an apartment with a balcony, this is an excellent method, as long as you don’t have to haul your fuel up 20 flights of stairs. (I speak from experience on this one.)
Portable gas-powered generators cost money, but maybe not as much as you might think. A generator that can handle a surge of 2200 watts will supply the big energy draw required by domestic fridges when the compressor kicks in. Most modern fridges won’t need that big generator to run them, especially if your fridge has an energy saver setting and was recently running.
I like having a portable generator because I can use it at my unserviced property to power tools and battery chargers. My father-in-law loves his generator for camping. Once you have a generator, you see the value.
A 2000w portable gas generator ranges from $350 to over $1000, depending on the features you want.
8. Portable Battery Generators
Don’t confuse these with UPS backup systems or battery banks that will charge your phone and cordless batteries. These are specialized power stations designed to handle AC appliances and professional tools that require a large amount of power.
Though they are relatively new to the scene, energy storage has come a long way in a short time.
Some all-in-one battery solutions can easily handle the high energy required to start a fridge’s compressor. While they tend to be much more expensive, people like them because they can be recharged in several ways, including solar panels. They also don’t give off any fumes, like gas generators or deep cell batteries.
I looked into the Goal Zero Yeti 1500X and crunched the numbers for my fridge. Using just a fully-charged Yeti 1500X, my fridge (rated at 6.2 amps) would run for about 25 hours before the battery would run out. If I were to charge the Yeti with three of their 100w solar panels every day, I should be able to run my fridge indefinitely.
But how much does a setup like that cost? A Yeti 1500X plus 3x100w solar panels will run about $2600. On the other hand, buying an all-in-one battery solution saves you from buying additional components like solar controllers. They also store very well.
Other options exist, but most of them just as expensive. I expect that to change because this is a market that’s growing incredibly fast. Using batteries for energy storage is in its infancy. Battery generators will become less expensive as alternative energy becomes the norm.
9. Buy a Propane-Powered Fridge
Propane-powered fridges are used for multiple reasons, and most revolve around the availability of power. Using a propane-powered fridge is usually reserved for those in rural areas where power isn’t as reliable as it is closer to cities and suburbs. They are also common for off-grid use and for cabins used at certain times of the year.
I’m not talking about the tiny fridges found in RVs and campers. Though these types of fridges have come a long way in the last couple of decades and would work in a pinch, they are smaller than most of us like to have in hour homes.
A handful of American manufacturers produce full-sized fridges and fridge/freezers that run on propane. Some are propane only, while others use propane as a primary power source but include a 110v electric backup system.
Don’t mistake the dual power fridges as something that can be run primarily on electricity. The electrical components are meant for use only as a safeguard for when propane runs out. Many manufacturers state that the electric backup systems are only rated for less than a year of service.
This is probably not the best use of your money or energy to keep a cold fridge with no power. If you are like me, the thought of using propane tanks indoors doesn’t make me very comfortable. Neither does switching tanks out every week. A better solution might be to have a propane fridge converted to natural gas. That still isn’t the best solution for those of us looking to keep our food from spoiling during a potential power outage.
10. Whole House Generator with Automatic Transfer
A whole-house generator works by using your natural gas supply to power your house. It has an automatic transfer switch right at your electrical panel. When it senses a power outage, the generator kicks in, feeding power to circuits predetermined to be essential. You can hook up anything you like, such as your fridge, freezer, lights, HVAC, sump pump, hot water tank, or anything you want to power.
Prices vary widely and can get out of hand quickly. Quotes from professional installers run from a few thousand dollars to way beyond, depending on the size of the generator you want.
Clearly, this is overkill for the average person looking to prepare for a rare blackout. However, suppose you have medical devices that need a constant power source or experience brownouts. In that case, this could be a real solution.
I’ve laid out several methods that you could use separately or together, depending on your needs and budget. Most of these come from personal experience, and others come from a lot of necessary research. I hope the information I’ve collected here helps you through your own preparedness journey.
In 2015, I experienced a 5-day blackout when a fire tore through an underground electrical locker near my apartment building. At the time, I had only lived through rare power outages that lasted a few hours at most.
I was lucky. This blackout only affected a few buildings in our neighborhood, and of those, most were office buildings. I wasn’t competing for resources like I would if the power outage had been city-wide. I was able to test my own methods on my own time. I didn’t have issues with price gouging or scarcity.
Over the 5 days, I tested a few different ways to keep my fridge cold, some of which I included in this article. I settled on a portable gas generator because it was the best way to keep my fridge cold as crews worked day and night to rebuild that entire locker. It made the most sense because no one knew when the work would be done. I ran it on my balcony, with an electrical cord running through a crack in my patio door.
That event is also what started my wife and me on this journey of self-reliance and emergency preparedness.