In general, using solar power is a great way to run an electricity-hungry appliance like your refrigerator. It will take between 2 and 4 panels to provide enough power to keep it running, depending on how often it is opened and how energy efficient your model is.
I’m still trying to decide if I want to power my entire house on solar energy, or just use it as a supplement. It’ll still save me some money and will take some strain off the electrical grid as well as our lovely little planet.
Four panels sound like a lot for one appliance, but there are some factors that go into this average that can be mitigated with some change of habits. Other factors could add or take away from the panels needed too, such as climate and model of the fridge.
Can A Solar Panel Run A Refrigerator?
On average, one solar panel, all by itself wouldn’t be enough to run a power-hungry appliance like a refrigerator. Like I mentioned above it’s going to take 2 to 4 panels to run the average household fridge.
Some of the factors that you should consider:
- Age of the refrigerator
- Style (Does it have an ice maker, in-door water, multiple freezer drawers, etc)
- How many cubic feet is your fridge
- How many family members do you have and how many times a day will it be opened and for how long will it stay open
- Do you keep your fridge moderately full or is jam-packed with groceries
- Do you keep your house at a warmer temperature, forcing the fridge to kick on more often
And there are likely other factors that may be unique to your family or lifestyle that will apply here as well, but these are the major ones that most everyone should consider.
So, how do you figure out how power-hungry your refrigerator is on a daily basis? This requires a little math…don’t worry, it’s simple math so stick with me here.
The first thing you need to do is figure out how much power your refrigerator needs. If you’re currently shopping for a fridge then it will likely be on a big yellow sticker prominently featured somewhere on a display model. If you already have a fridge then it will either be labeled in the door or available from the manufacturer’s website.
- Find the Estimated Yearly Electricity Use (let’s say it says 500 kWh)
- Divide this number by 365 to get the daily amount. 500/365 = 1.37 kWh
- Divide this number by 24 (to get the hourly need.) 1.37/24 = .057 kWh
- Multiply by 1000 to convert to Watts. .057 x 1000 = 57 Watts/Hour
For further reference, here are the numbers for three of the top-rated, mid-sized refrigerators at the time of this writing.
|Samsung French Door|
|27 Cu Ft||79 Watts/Hour|
|27 Cu Ft||73 Watts/Hour|
|25.5 Cu Ft||81 Watts/Hour|
So, we needed to get that information so that we could move on to figuring out how many solar panels you’ll need to run your fridge. To do this, we’ll use the Frigidaires stats since it had the highest yearly estimate of 709 kWh per year. We’ll also use a solar panel average production of 30kWh per month.
- Take 709 and divide it by 12 (getting the monthly average) = 59
- then divide 59 by 30 (solar panel output) to get 2 (I rounded)
That 2 means that to produce enough energy to run that Frigidaire on solar, you would need 2 panels to do so (each panel gets you to 30 kWh, so 2 gets you to 60 kWh.)
Then why did I say it would take 2-4 panels? I was accounting for older models that aren’t as energy efficient as todays models. As I was writing this I was going through the Lowes website clicking on random refrigerators, some listed as Energy Star rating and some without and I was hard pressed to find a fridge that had an average of over 750 kWh per year.
But his wasn’t the case a few years ago when this number would have been closer to 1000 to 1200 kWh per year, so I was allowing for people with older models that might be interested in using solar energy.
There is also the surge load (also called the starting load) to take into account. This is that initial power surge your fridge needs each time it starts up. The amount of power for the surge load is typically one and a half times the normal run load.
To figure this, just multiply the watts by 1.5. So a 700 watt fridge has a surge load of 1050 Watts.
But this is great news for people in the market for a new fridge that they want to run on solar power. Now it takes fewer panels to run a fridge which means you can save money by running more appliances on solar, or save money by having to buy fewer solar panels. Win-win!
What Equipment Will I Need To Run A Refrigerator On Solar Power?
In general, in order to power household appliances using solar power you will need solar panels, 160 amp hour battery, a charge controller, a power inverter, and all of the associated wires, cables, and framing.
Solar panels alone aren’t going to do much for you. You’re going to need some other gear to fill out your solar array and to get your home working on solar power.
Solar panels are only going to draw energy from the sun while it’s getting direct contacts with the suns rays. Some estimates say that you get the full brunt of solar rays for about 4 hours each day, with a ramp up in the morning and a drift off in the evening.
That’s not going to do you much good at night or when it’s very overcast out. So you’ll need some batteries to store all that solar energy. Most people use a 160 amp hour battery which means it will provide 8 amps of power per hour for 20 hours.
But there are 24 hours in a day…what happens during those 4 hours? Well, remember, your battery is charging up during the daylight hours and still pushing energy to your fridge, so there is plenty of overlap to keep your appliances going.
The batteries are going to be pushing DC (direct current) and your fridge will need AC (alternating current) to run. This is where the inverter comes in.
Between the solar panels and the battery, most people hook up a solar charge controller. This is going to help optimize the charging of your battery and prevent power from going out of your battery and back up to the solar panel once the sun goes down. In simple terms, it controls the flow of power.
An inverter will take DC power and turn it into AC power. An inverter unit will come in several wattage levels, so this is where some of that math we did earlier comes in handy.
The inverter box will have a display that will let you tab through several readings like wattage, amps, kilowatts, and more. The box itself will also have several three-prong plugs. This is where you’ll plug your fridge in and start enjoying all that sweet (and free) solar energy.
And finally, you’ll need some wires and cables to move the solar power from the panels to the battery, and from the battery to the inverter. You’ll need tray cables (cables with rings that will go on the positive and negative nodes of the battery) that lead from the controller to the battery, and from the battery to the inverter.
Many home improvement stores will sell all of this equipment separately in case you have different preferred brands for solar panels, batteries, and inverters. But you can also buy full kits that will have everything bundled together, including the wiring you’ll need to hook it all together.
Is Using Solar Power To Run A Refrigerator Cost-Effective?
Typically, if you are just planning to power a refrigerator using solar then the cost to purchase and set up your array likely isn’t worth the trouble or the cost. However, if you plan to run several appliances off this array, then the savings will add up over time and be worth your time and investment.
It’s true that setting up solar power has a significant upfront cost. Even if your state or county offers solar energy rebates and tax incentives, you still have to fork over the cash up front.
Going back to the three major brands of refrigerators, you can see what the estimated yearly kilowatt usage is, but that yellow tag also tell you what your estimated yearly cost to power the fridge is. Now, this is an average (and probably skewed low) and many things can affect this. The big one that pops to mind is energy costs in your area.
If you are purchasing a new fridge that is highly energy-efficient, which most are nowadays, and you moderate your visits to get a chilled snack, then the price of the solar setup to run the fridge will be paid for in a few years. If you plan to run the fridge until it’s an antique and live in your home for many decades, then the money saved will be compounded each year!