Whether you’re preparing for storm season, trying to lower your power bills, or working toward full energy independence, powering your fridge with solar is one of the most important steps you can take. Your refrigerator runs 24/7, and with rising grocery costs, keeping it cold during a power outage or emergency isn’t optional, it’s essential.
But how many solar panels does it take to run a fridge? And how much battery backup do you need to keep it going when the sun isn’t shining? We’re going to cut through the confusion with some real-world testing, a little bit of (simple) math, and a few practical examples you can use if you want to get started right away.
We’ll also provide a few useful resources that you can use when calculating the power requirements for any solar power system. Let’s get started.
There are plenty of exaggerated claims online about refrigerator energy consumption, but the truth is much simpler. We even published an entire article about it, which you can read here: How Much Power Does a Fridge Use?
If you don’t feel like reading the article or watching the video, the main takeaway is that we tested three average fridges in three different homes. Over a 24-hour period, they all consumed right around 1,300 watt-hours (Wh) of power.
While power requirements for any fridge will vary a little bit depending on its size, model, age, and the ambient room temperature, it’s a useful average, so that’s the number we’ll work with here: 1,300Wh per day for a standard fridge.
If you want the most accurate number for your own fridge, the best tool is a simple plug-in power meter (you can grab one on Amazon for cheap). Just plug the device into a wall outlet, then plug your fridge into the power meter. Run the test for 24 hours, then you’ll have the exact daily power consumption for your exact fridge.
It’s super easy to do, and it can be replicated to find power requirements for pretty much any appliance or device in your home.
Once you have your power requirements, you’ll need to decide how many days you want to be able to run your fridge and other appliances with solar. The average power outage is only 5.5 hours in the USA, so most of the time you can just keep your fridge closed and it will stay cold.
However, we’re more concerned with major outages, like those caused by storms, hurricanes, wildfires, and other serious events. In the next section, we’ll use three days of no grid power as an example.
Again, the actual number of days you'll need to calculate for will vary from person-to-person, so we recommend coming up with a number that you want to be able to run your appliances off-grid. If you rarely get outages that last more than a day, you won't need to generate or store as much power as someone living in a location where multi-day outages are common.
Once you know your daily consumption, the next step is to calculate how many solar panels you need to run your fridge. Basically, it’s time to find out how much solar power you will need to generate and store to keep your fridge running when the grid is down.
The math looks like this:
In our scenario, to run a fridge off-grid for three days, we would need a solar panel array that can produce 3,900Wh in 3.5 hours of peak sunlight.
When you divide that out, you get around 1,114 watts of solar capacity. To stay safe, we’ll round that up to a 1,200-watt solar panel array.
That could look like any of the following setups:
The exact solar panel configuration doesn’t matter. What does matter is hitting that 1,200W mark so you can charge your solar batteries or power station with enough solar energy during your available peak sun hours to keep your fridge running for three full 24-hour periods without sun.
Now, you might have sun available during a three-day outage, in which case you’d be able to recharge your batteries each day. But we always prefer to be safe rather than sorry when it comes to lengthy power outages and emergency situations.
So, we’re going to act as if there is no sun available during the outage itself, only before it hits.
The most important factor in this equation is your number of peak sun hours, which vary by location. Peak sun hours, or peak solar hours, are the hours during the day when the sun is at its strongest and panels generate their maximum rated power. For example, during peak sun hours, a 100W panel will generate close to 100W of power. Durning non-peak solar hours, that same 100W panel will generate less than 100W.
For example:
We recommend just using Google to find the average peak sun hours in your city. This is usually shown as a range, as the number of hours vary throughout the year, so we always use the lower number of peak sunlight hours to stay safe.
The U.S. Department of Energy has a handy PV Watts Calculator that estimates energy production for solar panels according to where they are located.
Solar panels generate the power your fridge needs, but without a battery to store that power, you won’t make it through the night or even a temporary cloudy stretch. That’s why battery sizing is just as important as solar array sizing.
Here’s how it would break down in our 3-day fridge backup example:
Why go bigger than the math suggests? Because of idle consumption caused by your solar inverter. This is the component that converts the DC power your solar panels generate into the AC power your fridge and other appliances run on.
Even when your fridge isn’t actively cooling, your solar power system inverter, or the inverter inside your power station, draws small amounts of energy just to stay on. We usually call this idle power consumptioin.
Over several days, that idle power adds up. Having a buffer ensures you don’t run out of power and have to worry about your fridge unexpectedly shutting down. Oversizing your battery also gives you wiggle room to run other loads during your outage, like extra appliances or even just charging portable devices, like phones and a laptop.
If you’re still feeling a bit confused, we put together a guide that could be helpful: Sizing Battery Capacity for Your Solar Power System
Whether you choose a traditional grid-tied or off-grid solar power system (panels + batteries + inverter) or a portable power station with a built-in inverter, you’ll need an inverter that is capable of handling your fridge’s power requirements.
Most fridges are rated for 300 to 600 watts, meaning they pull that amount of power at their peak. They don’t constantly use that much, but when they kick on after defrosting or cooling down, they can spike up to their rated max. Your inverter just needs to be sized above that number.
Portable power stations make the entire setup simple because they combine the inverter, battery, and solar input into one unit. They’ll also advertise the unit’s inverter capabilities very plainly. It's usually listed as the unit's output power or continuous power rating.
For example, something like a Pecron F3000 Power Station has a 3,600W inverter output, so it could easily handle a fridge.
If you’re unsure which to get, check out our How to Pick the Right Power Station Guide or take our quick Power Station Quiz, which will match you with a power station we recommend based on your needs and budget.
If you’re purchasing a standalone inverter for a traditional solar power system, it’s the same thing. Just check that the continuous output rating is higher than the maximum wattage required to run your fridge.
In a lot of cases, the output is listed right in the name of the unit, so you don't even have to check the specifications. Take the EG4 3kW Off-Grid Inverter, which unsurprisingly, has a 3,000W (3kW) output. Again, more than enough to run a standard household fridge.
Powering a fridge with solar isn’t as complicated as it seems. Once you know your fridge’s daily energy use and your local peak sun hours, you can quickly calculate how many solar panels and how much battery capacity you’ll need. From there, you just need an inverter or power station that can match the maximum wattage requirements for your specific fridge.
In most real-world cases, a 1,200W solar array paired with a 4,500Wh to 5,000Wh battery will keep your fridge running for days at a time, even through cloudy weather. And if you live in a sunnier region with more peak sun hours, you could probably get away with half that.
If you want to dive deeper, check out these videos:
At the end of the day, your fridge doesn’t use nearly as much power as you probably think. Most people just assume that because fridges are big and always in use, they need a lot of power to stay running. In reality, even with a basic power station or permanent solar setup, you’ll never have to worry about your food spoiling during an outage again.
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