How Much Solar Power do I Need to Run a Refrigerator

How Much Solar Power do I Need to Run a Refrigerator

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If you are asking yourself the question – “how much solar power do I need to run a refrigerator,” you have come to the right place! In this article I will tell you exactly how much solar power you will need to run a refrigerator. I will show you specific examples based on fridge size and solar panel size. Let’s get started!

Refrigerator Watts

The first thing you need to figure out the wattage rating of your refrigerator. You can do this by finding the amps and the volts on the electrical label on the device. To find the watts you multiply amps times volts.

Amps x Volts = Watts

You need to know it’s approximate starting wattage and the wattage required to run. The equation above will give you the watts required to run. Refrigerators require more power to start than they do to run. You can estimate the starting wattage by multiplying the watts by 1.5.

Example: refrigerater rated at 6.5A 110V = 715

Maximum Starting Watts: 1,073watts

The words “surge” or “starting load” or “starting watts” is used interchangeably.

Running Watts

Another technique is to use the annual kwh usage of the refrigerator to determine the running watts. Most of the time, fridges will show their annual kwh energy consumption on the label. Or if you search for your fridge model online, you should be able to find out the annual kwh energy consumption. For example, I found a fridge that uses 404 kwh per year. Divide that by 365 to get 1.11kwh per day. Divide by 24 and multiply by 1,000 to get the watts. So this fridge runs on about 46 running watts. Below is an example of the energy guide label you can find with your annual kwh usage.

Solar Power vs Battery Power

Really, the question should be how much power do I need to power a refrigerator. Because you can’t power a fridge on solar panels alone. At night there will be no power for the fridge and it will shut off. The solar panels have to be connected to a battery and inverter to provide power to your fridge. The solar panels will charge the battery and keep it ready to supply power to your fridge.

Inverter

If you have an inverter it will need to handle about twice as much as the maximum load, so a 2,200w inverter should work for this example. (because the max starting watts is 1073 watts)

Battery

Your battery is also going to have to be able to handle the load without being depleted. For this example, you would need a battery bank of at least 300ah. You can see how this was calculated below.

66 Watts per hour * 24 hours = 1584 watts

1584 watts / 12 volts = 132 DC amps

132 DC amps * 2 = 264 ah

I multiplied the 132 DC amps by 2 because you don’t want your battery to go below 50%. I am going to make a calculator for this at some point.

Solar Panels

Lastly you will need the solar panels to keep the battery charged. For this example, if you are using 404 kwh per year, that is 1.11 kwh per day. So you are going to need a total wattage of 300 combined solar panels. How did I come up with 300? You multiply the combined wattage of the solar panels by the number of hours sunlight they will receive per day. A good rule of thumb is 4 hours. 300 times 4 is 1200 watts. 1200 watts divided by 1,000 equals 1.2 kwh produced per day.

Charge Controller

Now if you are going to set up your solar system yourself you will also need a charge controller, running from the solar panels to the battery so that the battery doesn’t get overloaded.

Solar Generator

Alternatively you can purchase a solar generator with the amount of watts you need. For this example you will need at least a 1,100 watt solar generator. Check out our solar generator guide.

Conclusion

Now, the answer to the question, “How Much Solar Power do I Need to Run a Refrigerator?” is not a simple answer because it is not a simple question. Hopefully my explanations have helped you figure out how much power you need to run a refrigerator.

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