How Many Solar Panels to Power a Refrigerator: Everything You Need to Know
Running your fridge on solar power is a smart idea, especially if you’re off-grid, trying to cut utility bills, or preparing for backup power. But before installing panels, you’ll need to know how much power your refrigerator actually uses and how many solar panels to power a refrigerator.
This guide breaks it all down. We will show you how to calculate your fridge’s power draw, how to size your solar system correctly, and what else affects performance. Plus, we’ll cover whether a battery is necessary and how long it can run your fridge when the sun isn’t shining. Keep reading to learn more!
How Much Power Does a Refrigerator Use Per Day?
Before sizing your solar setup, you’ll want to understand how much electricity your fridge uses on an average day. The daily energy use of a refrigerator depends on how much power it draws and how long it actually runs. Even though it's always plugged in, the compressor cycles on and off to maintain the set temperature. On average, it operates at full power for 8 to 12 hours a day.
Here’s how you can estimate the daily power usage:
Step 1: Find the wattage of your fridge
Most standard refrigerators use between 100 and 400 watts when running. You can usually find this on the manufacturer’s label inside the fridge or on the back. It might be listed in watts (W), or sometimes as volts and amps. If it’s the latter, use this formula to calculate watts:
Volts × Amps = Watts
For example, if your fridge uses 120 volts and 1.5 amps:
120 V × 1.5 A = 180 watts
Step 2: Estimate how many hours it runs per day
A refrigerator doesn’t run non-stop. Most run at full power for about 8 hours a day in short bursts.
Step 3: Multiply the wattage by the runtime
Using our earlier example of a 180-watt fridge running 8 hours a day:
180 W × 8 hours = 1,440 watt-hours per day
That equals 1.44 kWh per day, which is the unit most electricity bills use.
How Do You Calculate the Number of Solar Panels You Need?
Once you know how much energy your fridge uses each day, the next step is to figure out how many solar panels it’ll take to cover that demand. This involves a bit of simple math, factoring in the power output of each panel and how much usable sunlight you get.
Here’s how to work it out:
Step 1: Estimate your daily sun exposure
In the UK, solar panels don’t get full-strength sunlight all day long. On average, there are around 2.5 peak sun hours per day—the time when panels produce energy at or near their rated capacity.
Step 2: Know your panel’s output
Let’s assume you're using a 300-watt solar panel, which is fairly standard for residential systems.
Step 3: Use this formula
Divide your fridge’s energy needs by how much one panel can generate in a day:
1,440 Wh ÷ (300 W × 2.5 hours) = 1.92 panels
Since you can’t install a fraction of a panel, round up to 2 panels. That setup should fully cover your fridge’s daily usage during sunny periods. If you're planning for cloudy days or want to charge a battery for nighttime use, adding a third panel can provide that extra buffer.
Can I run a refrigerator using solar power when I go camping? Yes, you can run a portable refrigerator on solar power while camping. The EcoFlow GLACIER Classic Portable Fridge Freezer, paired with its 110W portable solar panel, offers an eco-friendly solution for keeping your food and drinks cool off-grid. With efficient cooling and multiple charging options, including solar, AC, car outlet, and USB-C, the GLACIER Classic ensures your perishables stay fresh wherever your adventures take you.
EcoFlow GLACIER Classic Portable Fridge Freezer
Do I Need a Battery to Run a Refrigerator with Solar?
In short: Yes, if you want your fridge to run when the sun isn’t out.
Solar panels only produce electricity during daylight hours. Your refrigerator, however, needs power 24/7. That’s why you need a battery. But what’s the size of your storage battery?
To figure that out, you need to calculate how much energy your fridge uses at night, and then factor in the battery's efficiency.
Let’s say your fridge consumes 1.44 kWh per day, and you want to store enough energy to keep it running during the evening and overnight hours. Since no battery is perfectly efficient, we need to account for energy loss during storage and conversion. For a lithium-ion battery with about 95% efficiency, here’s how the math works:
Battery Size = Daily Energy Need ÷ Battery Efficiency
1,440 Wh ÷ 0.95 = 1,516 Wh
So, you’d need a battery that can hold at least 1,516 watt-hours (or 1.52 kWh) to comfortably power your fridge through the night.
Going slightly larger gives you a safety net for cloudy days or future energy needs. A 1.6 kWh to 2 kWh battery would be a smart choice for reliable, round-the-clock operation.
That said, some portable fridges are far more efficient and designed to work with smaller, dedicated batteries. Take the EcoFlow GLACIER Series, for example.
What Affects the Efficiency of Your Solar Setup?
Even with good calculations, solar performance isn’t always perfect. Several things can reduce the panel’s solar power for refrigerator.
1. Panel Angle and Orientation: For UK homes, the optimal tilt is around 30–40°, facing true south. Panels not properly aligned can lose up to 20–30% of their potential output over the year.
2. Shading: Even partial shading of a panel can reduce total system output by up to 50%, depending on how panels are wired. One shaded cell can drag down the performance of the whole string.
3. Temperature Impact: Solar panels operate most efficiently around 25°C. For every 1°C rise above this, output drops by about 0.3–0.5%. In hot weather, this can result in a 10–15% loss in efficiency.
4. Dirt, Dust, and Debris: Studies show that dirty panels can lose 5–10% of energy yield. In areas with heavy dust or bird activity, losses can be even higher. Cleaning panels every few months can restore lost efficiency.
5. Inverter Efficiency: Inverters typically have an efficiency rating between 93% and 98%. Cheaper or older models may lose more energy during the DC to AC conversion process. Choose one with a high European Efficiency rating for consistent performance.
6. Battery Efficiency and Management: A good lithium battery operates at about 90–95% round-trip efficiency. If not properly managed, energy can be lost through heat, overcharging, or inefficient discharge. A smart battery with a reliable BMS (Battery Management System) helps reduce waste and extend lifespan.
Conclusion
To run a fridge on solar, you only need a few key numbers: how much power your fridge uses, how much sunlight your panels can catch, and how efficient your system is. Once that’s clear, figuring out how many solar panels to power a refrigerator is simple math. Add a battery, and you're covered day and night. If you're after something reliable and easy to set up, EcoFlow solar powered freezers and refrigerators make it easier to switch to solar without overthinking the details.
FAQs
What size solar panel do I need to run a fridge?
The size of the solar panel you need depends on your fridge’s daily energy use and how much sun you get. For example, if your fridge uses around 1.44 kWh per day and you get 2.5 peak sun hours, a 300W panel would produce 750Wh daily, so you’d need at least two panels. To stay powered consistently, especially in cloudy weather, adding a third panel or battery storage is a smart move.
Can you run a fridge directly from a solar panel?
Yes, you can run a fridge directly from a solar panel, but only while the sun is shining and the panel is producing enough power. Since solar output fluctuates with clouds and time of day, the fridge may stop running if the supply drops.
For consistent operation, especially overnight, it's best to connect the solar panel to a battery and an inverter system. This setup stores excess energy and delivers stable power when the panel isn’t generating electricity.
How long will a solar battery run a refrigerator?
How long a solar battery can run a refrigerator depends on the battery’s capacity and the fridge’s power usage. For example, a fridge using 1.44 kWh per day and a fully charged 2 kWh battery (with 95% efficiency) could run for about 1.3 days without additional charging.
Larger batteries or fridges with lower energy use will extend run time. To ensure 24/7 operation, it’s smart to size your battery slightly above your fridge’s daily energy demand.