What Can a 400 Watt Solar Panel Run?

  • By: Preetam
  • Date: August 21, 2022
  • Time to read: 8 min.

Are you using solar energy to cut back on your utility bills? Then you may wonder, what can a 400 watt solar panel run?

A 400 watt solar panel can run the following appliances: a TV, a laptop, a crockpot, lights, fans, a sound system, an electric blanket, a blender, paper shredders, and similar items. 

Of course, that is not a complete list of appliances that your solar panels can run. 

Are you ready to find out just what yours are capable of? Then make sure you check out the rest of this article.

How Much Can a 400W Solar Panel Power?

Do you have a 400W solar panel on your property? Then you’ll want to put it to good use and make the most of this energy-saving equipment. 

But how much can a 400W solar panel power? You can use 400W solar panels to power the following: a TV, a laptop, a crockpot, lights, fans, a sound system, an electric blanket, a blender, and paper shredders.

There is a long list of appliances that you can power with a 400W solar panel. But it’s important to also mention that you will not be able to run any large appliance with it. 

By large, we don’t mean in size but rather in consumption. Here are a couple of things that you cannot run: a toaster, a microwave, a kettle, a washing machine, an electric oven, an electric fireplace, and the like. 

How many appliances your 400W solar panel can run is also dependent on more features. What are they? 

Here are just a few of them:

  • Your charge controller. A PMW charge controller will not run your solar panels as well as an MPPT controller
  • The weather. If the skies are cloudy, even if there is no rain, the solar panels will be affected. You will see a drop in your Amps when the weather is overcast.
  • Shading. You need to keep the solar panels clean in order for them to work properly. They shouldn’t be covered in dirt, dust, leaves, or any other debris. 

Can a 400 Watt Solar Panel Run a Refrigerator?

If you have a 400 watt solar panel at home, you are no doubt wondering which appliances you can run off of it. 

What about some of the large appliances you have such as a refrigerator? Can a 400 watt solar panel run a refrigerator? The short answer is yes, it can. 

But allow us to go into some more detail that will make sure this works for you. 

For your 400 watt solar panel to run a refrigerator, it needs to be small. That means it shouldn’t have a capacity of more than 20 to 30 liters. 

You will not be able to run a fridge larger than this off of your solar panels. It also depends on how many hours the fridge is on per day and how many amps it pulls while it runs. 

Your refrigerator will only be able to run on solar panels if you have the right equipment. This includes a battery bank. 

The bank will store sunlight energy that is gathered throughout the day. The energy is then used at night while there isn’t any sunlight.

 You will also need a solar charge controller. The controller will boost your power production and protect the solar panels. 

In summary, for your refrigerator to run off of 400 watt solar panels, it should meet the following criteria: 

  • It should be small and have no more than a 30-liter capacity
  • It should have a 20-40AH average power usage
  • It should only consume between 1500 and 2000WH of energy each day
How Many Batteries Do I Need for 400 Watts of Solar?

How Many Batteries Do I Need for 400 Watts of Solar?

You can save a massive amount of energy when using a 400 watt solar panel. But what if you’re out all day and are only home in the evenings after the sun goes down? Then all of the energy you could have been saving in the day will be lost. 

That is why you need a battery to hold onto the energy you save. But what battery size is right for 400 watt solar panels?

How much battery storage you need depends on how many hours of sunlight are available. It will also depend on how many watts your solar panels can produce in a day.

 If your solar panels produce 1200 to 2400 watts per day you will need a 200 AH AGM or lithium battery to store the power. Your battery power should match your voltage.

Solar panel outputSun hours per dayWatts/battery size
400 (Optimal conditions)
400 (Optimal conditions)
360 (Good conditions)
360 (Good conditions)
5
7
5
7
2000
2800
1800
2500

Now you’ll notice here that we have different outputs mentioned depending on the conditions. That is because although your solar panels may be 400 watt, they will not always be able to work to their maximum potential. 

This could be for many reasons such as passing clouds, an overcast day, or even a system failure.

Is 400 Watts of Solar Enough?

Are you trying to decide what capacity of solar panel to install on your property? Perhaps you have considered a couple of options and have settled for 400 watts. 

But you may still wonder, is 400 watts of solar enough? Yes, it is! There is so much you can do with 400 watts of solar energy. 

Here are just some of the reasons why this is a great option for the average family:

  • 400 watts is enough energy to power lots of small appliances. This includes your TV, laptop, blender, printer, shredder, and a bunch of other small appliances. 
  • 400 watts of solar panels can fit on your average family roof. Most homeowners are reluctant to go for a higher wattage because they will not be able to fit the solar panels on one roof. 400 watts is ideal for the average family home. What if you don’t want your solar panels on your roof? If you have a large yard, you may also be able to consider a ground-mounted solar panel space.
  • 400 watts of solar panels is enough to decrease your electric bill. Every day, you will be able to charge some of your electrical appliances using your solar panels. This will save you money on your electric bill at the end of the month. 
  • 400 watts of solar panels are great for an RV or a boat. Most homeowners go with 300 watts of solar panels to reduce the cost of their utility bills. But if you plan on powering an RV or a boat, having the extra 100 watts is key to keeping the cost down for powering your favorite getaway transport.

What do 400 watts of solar panels produce? You are looking to produce between 1 and 3 kilowatt hours each day. 

This makes them the ideal choice for both residential and commercial buildings. 

Is 400 Watts of Solar Enough?

How Many Solar Panels Do I Need to Run a Refrigerator?

Installing solar panels is a great way of saving money on your utility costs. One of the appliances we have at home that is constantly draining on our electrics is the refrigerator. 

Are you looking for a way to take a little bit of the strain off of your bills by running the fridge on solar panels? Then how many solar panels will you need to run it?

How many solar panels you will need to run a refrigerator depends on the amount of solar energy the panel can produce in one day. 

The higher its production, the fewer solar panels you will need. But this is not the only factor at play, here are some other variables you will have to contend with:

  • The size of the refrigerator. The larger the appliance, the more solar panels you will need to run it.
  • How often the refrigerator is running. Older refrigerators are less energy efficient. They often have longer running times and will therefore need more solar panels to keep them going.
  • How many amps the refrigerator uses when it is on. The more energy your refrigerator uses, the more solar panels you will need. 
  • The equipment you use. A battery pack is ideal for storing sunlight energy after the sun goes down. You will need this to continue operating the fridge throughout the night.

If you run a small refrigerator that holds less than 30 liters, with 20-40AH average power usage, you can power it using 400 watt solar panels. 

How many solar panels you will need depends on their capacity. If one solar panel produces 1 KW of solar energy per day then you will need 4 solar panels to power your refrigerator. 

What Size Solar Panel Do I Need to Charge a 12V Battery?

Charging your battery is very important as it is the only way to guarantee you will have electrical power when the sun goes down or during an overcast day. 

But how long will it take for a solar panel to charge your battery? Well, there isn’t a straightforward answer to this question as there are many things that can alter the battery’s charge time. 

Here are some of them:

  • The weather and the position of the sun in the sky
  • How empty the battery is
  • The type of battery

Let’s look at these one at a time starting with the weather and the position of the sun in the sky. When the weather is overcast, the solar panels will need longer to charge a battery. 

If the sun is high in the sky in the summer, the battery will charge faster. Low sun in the winter will cause the battery to charge slower. 

A completely drained battery will take longer to charge than one that is only partially drained. It could take a solar panel 5 to 8 hours to energize the cells of an empty battery. 

The type of battery you are trying to charge is also important. Lithium iron phosphate batteries charge faster than lead-acid batteries. 

This is especially true as the lead-acid battery reaches full charge.

How Many Amps Is 400W at 12V?

Converting watts to amps is important when running any electrical appliance. 

This will help you to calculate how much energy the appliance will use and at the end of the day estimate your electric bill. 

Converting watts to amps is easiest though when we know the formula. Here’s the formula you will need.

  • P = I x V
  • (P) Power = (I) Current x (V) Potential Voltage
  • Power is measured in Watts (W). Current is measured in Amps (A). Potential voltage is measured in Volts (V).

So how can we use this formula to calculate how many amps 400W is at 12V? Take a look at the following breakdown of the steps that will lead us to the answer.

  • P = I x V
  • (P) Power = (I) Amps x (V) Potential Voltage
  • 400 Watts = (Amps) x 12 Volts 
  • To work out the Amps we must invert the formula and divide the Power by the Potential Voltage. (Divide the Watts by the Volts).
  • 400 divided by 12 = 33.3
  • 400 Watts = 33.3 Amps x 12 Volts
WattsVoltsAmps
11283 (milliamps)
1012830 (milliamps)
100128.33
2001216.67
4001233.3
5001241.7
10001283.3

Final Thoughts

Do you have a solar panel system at home? Then you might be wondering what can a 400 watt solar panel run?

In this article, we have seen that you can run a number of small appliances off of a 400 watt solar panel. 

These appliances are low wattage but still add up if you were to run them all day. These include appliances like blenders, shredders, TVs, laptops, crockpots, electric blankets, lights, sound systems, and similar items. 

Every time you connect one of them to your solar panels, you’re putting money back in your pocket. 

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