What size solar generator to run refrigerator and freezer?

What size solar generator to run refrigerator and freezer?


When it comes to running a refrigerator and freezer using a solar generator, it is essential to determine the appropriate size of the generator to ensure reliable and efficient operation. In this article, we will explore the factors to consider and provide guidance on selecting the right size solar generator for your refrigerator and freezer.

Power Requirements

To determine the size of the solar generator needed, it is crucial to understand the power requirements of your refrigerator and freezer. Typically, the power consumption of these appliances is measured in watts or kilowatts. You can find this information on the manufacturer’s label or in the user manual.

The power consumption of refrigerators and freezers can vary significantly depending on factors such as size, age, energy efficiency rating, and usage patterns. As a general guideline, a small refrigerator may consume around 100-200 watts, while a larger one can use 400-600 watts. Freezers usually have similar power requirements.

Calculating Energy Consumption

To determine the energy consumption over a specific period, you need to consider the wattage and the average daily usage. For example, if your refrigerator uses 150 watts and runs for 10 hours a day, the daily energy consumption would be 150 watts x 10 hours = 1500 watt-hours or 1.5 kilowatt-hours (kWh).

It is important to note that refrigerators and freezers do not run continuously. They cycle on and off to maintain the desired temperature. The average duty cycle, which represents the percentage of time the appliance is running, is typically around 50%. Therefore, you can estimate the actual energy consumption by dividing the daily energy consumption by the duty cycle. In this case, it would be 1.5 kWh / 0.5 = 3 kWh.

Sizing the Solar Generator

Once you have determined the daily energy consumption of your refrigerator and freezer, you can calculate the size of the solar generator needed to power them. Solar generators are rated in terms of their capacity, usually in watt-hours or kilowatt-hours.

To ensure reliable operation, it is recommended to have a solar generator with a capacity at least 20-30% higher than the estimated daily energy consumption. This additional capacity accounts for factors such as inefficiencies in the system, cloudy days, and potential increases in power requirements in the future.

For example, if your estimated daily energy consumption is 3 kWh, a solar generator with a capacity of 3.6-4.5 kWh would be suitable.

Other Considerations

In addition to the size of the solar generator, there are a few other factors to consider when running a refrigerator and freezer using solar power.

Battery Capacity: Solar generators often include a built-in battery to store excess energy generated during the day. It is important to ensure that the battery capacity is sufficient to meet your needs, especially during periods of low sunlight or overnight.

Solar Panel Capacity: The solar panels connected to the generator should have enough capacity to recharge the battery fully within a reasonable timeframe. Consider the available sunlight in your location and the solar panel’s efficiency when determining the required capacity.

Inverter Size: An inverter is necessary to convert the DC power generated by the solar panels into AC power for your appliances. Ensure that the inverter can handle the peak power requirements of your refrigerator and freezer.


Selecting the right size solar generator is crucial for running a refrigerator and freezer efficiently. By calculating the energy consumption, considering additional factors, and choosing a generator with sufficient capacity, you can ensure reliable and uninterrupted operation.

Remember to consult the manufacturer’s specifications and seek professional advice if needed to ensure compatibility and optimal performance.


– Energy.gov: energy.gov
– Solar Reviews: solarreviews.com
– Consumer Reports: consumerreports.org