Let’s start off with the good news… Yes, it is possible to run a refrigerator from a 100 watt solar panel.
But it is important to understand the best way to do it and the limitations of using 100 watts of solar power.
For example, if you hook up your equipment incorrectly you’re going to have inconsistent results and a warm fridge.
This article will show you how to easily set up your solar panel and fridge. Plus how to avoid disappointing results.
Can a 100 Watt Solar Panel Power a Fridge?
If you try to run a refrigerator directly from a 100 watt solar panel, it’s not going to work.
Even if you have a power inverter to run your fridge, the solar panel is not going to be powerful enough.
This is because the average domestic refrigerator uses more than 100 watts for cooling. In fact, they can use well over 300 watts!
Adding to this, a solar panel is reliant on external factors, mainly sunlight, to generate electricity. This means they rarely produce a consistent amount of power.
In order to run a fridge from a 100 watt solar panel you will need the following components:
- Solar panel (duh…)
- Charge controller – controls battery charging
- Deep cycle battery – Stores energy
- Power inverter – Draw power from the battery and convert DC to AC
How Much Power Will a 100W Solar Panel Actually Produce?
You will rarely be able to generate 100 watts from your solar panel. This is the maximum amount of power based on ideal conditions. E.g. direct sun at peak hours.
Quite often you might only be generating 80% or 90% of this total depending on where you are in the world and the time of year.
You can reasonably expect a 100 watt solar panel to generate 400Wh of electricity over the course of a sunny day.
If you don’t have any direct sunlight hitting your panel then power output will drop significantly. On a cloudy day, solar panels only produce 15% – 30% power, so you will really be struggling.
Because a refrigerator uses more than 100 watts at some points and inconsistencies with solar panels, you will need to use a battery in your setup. This allows the solar power to charge up the battery and the fridge to draw energy from the battery.
How Many Watts Does a Refrigerator Use?
The average domestic refrigerator uses around 200 – 500 watts depending on size and efficiency.
This might seem like a lot but you first need to understand how it works. A refrigerator does not always draw this much power. It will work in cycles to keep itself cool. For example, a 300 watt fridge will only use 300 watts when cycling on for cooling. You might hear its compressor kick in after you open the door and let warm air inside.
The rest of the time, power draw will be much less as they are well insulated to hold low temperatures inside.
This is good news, as you can cope with these peaks and troughs with the right solar panel and battery setup. Plus, it won’t deplete your battery energy as quickly as you think.
When spread out over the course of a day, you will find that a fridge uses between 1000 – 2000 Watt-hours (Wh) of electricity (or 1Kwh – 2Kwh.)
How to Power a Fridge with a 100 Watt Solar Panel
To run a fridge for a 100 watt solar panel you need to include a battery in your system.
Here’s a step by step guide to connecting everything:
- Start by connecting your solar charge controller to your deep cycle battery via the positive and negative terminals. Always do this first.
- Connect your solar panel to your charge controller. This will allow the solar panel to safely charge your battery.
- Hook up your power inverter directly to your battery via the positive and negative terminals.
- Once your battery is charged, plug your refrigerator into your power inverter.
- Switch on your power inverter and run your refrigerator.
By hooking up your equipment in this way you enable your solar panel to continuously charge your battery. Then your fridge draws energy from the battery via the power inverter. As long as your inverter is big enough to run your fridge, the system should cope with peaks and falls in the power draw.
Unfortunately, don’t expect this to keep your fridge running 24 hours a day. Eventually, the refrigerator will deplete your battery quicker than the 100 watt solar panel can charge it. You will quickly notice this at night when energy production stops.
If you want to keep it running continuously, you will probably need 3 or more solar panels and ensure your batteries are large enough (at least 200Ah capacity) to last during the night or cloud cover.
How Long to Charge a 12V Battery with 100 Watt Solar Panel?
So now you’ll be wondering how long it takes a 100 watt solar panel to charge a 12V battery.
Well, this depends on sunlight and battery size. You can expect your solar panel to produce 5 amps of energy in direct sun. This will deliver about 25Ah over the course of a day.
Knowing you can generate 25Ah in a day, you can compare this to the size of your battery. For example, it would take two days to charge a 50Ah battery.
Try a 12V Camping Fridge Instead!
If you’ve read this far, you should understand the difficulties in running a fridge from a 100 watt solar panel.
To be honest it’s not achievable for any prolonged period of time. In reality, you’ll need more solar panels and big batteries.
That’s why I’d recommend using a smaller 12V camping fridge which only uses between 40 – 60 watts. You could happily run this from a 100 watt portable solar panel.
Or if you just want to keep soda cans cool at the beach you could use a 12V electric cool box during day trips.
What Else Can a 100W Solar Panel Run?
100 watt solar panels are one of the most common sizes. In fact, you might already have one that you’re keen to use. Well, even though you might struggle to run a fridge, you can still power a whole range of electronics including:
- Phone chargers
- Laptops
- Digital camera
- Small TVs
- Mini-fridge
- LED lighting
- Fans
- Tablets
- Portable gadgets
- Flashlight
- Emergency lighting
- Speakers
- Headphones
Final Words on Running a Fridge Off a 100 Watt Solar Panel
The bottom line is that you will likely need more than 100 watts to run a refrigerator.
You will be able to power your fridge for a short while with the inclusion of a deep cycle battery. But even then, the appliance will start to deplete your battery quicker than the panel can charge it. Once night falls, you won’t have charged your battery enough to keep it running.
If you want to use it as a power backup for a few hours during an emergency then this would work nicely. For anything longer you will need 3 or 4 solar panels and large deep cycle batteries of 200Ah+.
For off-grid applications, I suggest you stick to lower wattage 12V fridges to reduce energy demands. And for day trips look at 12V cool boxes and a portable solar panel to get the job done.
