Knowing the energy consumption of an appliance gives you a great insight into how much it would cost to operate. Here will specifically look at what is the power consumption of a microwave oven.
A home microwave oven typically consumer anywhere between 1100 Watts to 1850 Watts per hours. In other words microwave ovens have a 1.1 kWh – 1.85 kWh rating. An average microwave oven has about a 1.4 kWh rating.
Generally speaking, a microwave oven is pretty cheap to operate. Since it is only used for minutes at a time, it does not consume constant energy unlike lighting and air conditioning.
With that, let us delve a bit deeper into this topic. If you are unaware, the first thing you need to do is familiarize yourself with the different between power rating and power consumption of an appliance.
Power Rating vs Power Consumption
Power rating and power consumption are two different yet related aspects of any electrical device.
Power rating defines the peak power that the appliance would draw from the wall socket in order to operate. Basically, if this rated power is not supplied, then the microwave oven may malfunction. Power rating is specified using the unit Watts (W) or Kilowatts (kW)
Power consumption is defined as the energy consumed by an appliance in an hour. You are billed based on the energy consumption and NOT on the rated power. Power consumption is defined using the unit Kilo-Watt-Hour (kWh).
Let Us Simplify This With an Example:
If a microwave oven has a rated power of 1400 Watts (1.4 kW), then its consumption would be about 1.4 kWh IF it were continuously on for an hour.
If the same microwave oven was only on for half an our, its consumption would be half as that or 0.7 kWh.
Furthermore, if the same microwave oven is only on for a minute its consumption would be 0.023 kWh (i.e 1.4 kWh / 60 minutes).
What is the Power Consumption of a Microwave Oven?
As mentioned earlier, the input power rating of a microwave oven ranges from 1100 – 1850 Watts (1.1 to 1.85 kW) for a home-based microwave.
It is important to note here that you have to take the INPUT POWER into consideration when calculating the consumption and NOT the OUTPUT POWER.
You may be familiar with the common output powers for microwave ovens that range from 700W to 1250W for typical home use. However, these do not reflect the power drawn from the wall instead they define the power that is converted to microwave radiation.
Also Read: Microwave Input vs Output Power
A typical microwave oven has an efficiency of 65%. Meaning 65% of the INPUT POWER is converted to the OUTPUT microwave radiation.
The following are the typical OUTPUT wattage ratings for home microwaves.
- Low-Powered: 700W – 900W
- Medium-Powered: 1000W – 1100W
- High-Powered: 1200W and beyond
Taking a typical efficiency of 65% we get following Input Power for the corresponding Output Power as well as the corresponding consumption.
- 1100 W Input – 700 W Output – 1.1 kWh Consumption
- 1350 W Input – 900 W Output – 1.35 kWh Consumption
- 1700 W Input – 1100 W Output – 1.7 kWh Consumption
- 1850 W Input – 1200 W Output – 1.85 kWh Consumption
In other words a 700 Watt Microwave oven would consume 1.1 kWh of energy if it is operated continuously for an hour. On the other hand, a 1200 Watt microwave would consume 1.85 kWh of energy if it operated continuously for an hour.
How to Reduce Consumption?
There are plenty of ways you can reduce consumption on a microwave oven, let us review a few.
Power Level Selection
The first and for most important is the Power Level selection.
Power Level selection is offered in almost all microwave ovens. It allows you to set the percentage of the total output power that the microwave should operate at.
Different food or tasks require different Power Level selection.
The thing to note here is that if you set a power level of 100%, the microwave would operate at peak consumption. However, the same microwave would half its consumption for the same cooking cycle IF its power level is set to 50%.
Most microwave ovens have a total of 10 power level settings ranging from 1-10 with each setting representing a 10% increment or decrement.
Take defrosting, for instance. This task can be done fairly well even at 400 W output power. So if you have 1000 W microwave oven, you can set it to Power Level 4. Here it would not only defrost your food, but also consume mere 40% of the max power consumption.
Similarly, when keeping food warm, you can set the microwave to just 10% consumption or Power Level 1.
Set Accurate Cooking Cycles
Each food has a typical time cycle settings. Operating beyond that would results in only dehydrating your food of water but also result in needless energy consumption.
When reheating food, a microwave oven generally tends to reach a max of 212 degrees Fahrenheit or 100 degrees Celsius which is the boiling point of water.
When food reaches this temperature, the goal of the microwave is achieved. To save energy, you should therefore, not operate any longer.
Take water for instance. In a 1200 Watt microwave oven, it takes about 45 seconds for a glass of water to reach the boiling point. Operating the microwave oven beyond this would be futile since that would only convert the water into steam.
The same glass of water would take about 2 minutes in a 700 Watt microwave oven.
Hence, it is important that you know the power of your microwave as well as the PRECISE cooking time for various type of foods in your microwave.
Stir the Food / Use Small Portion
If you have a habit of loading up your microwave with food for reheating or defrosting, the you are doing it completely wrong.
Densely packed food or large portions of food are hard for microwaves to heat up. This is especially true if you have low powered model
Hence, instead of increasing the time cycle for reheating the large meal, it is rather advisable to stir it from time to time.
Better yet, you can use smaller portion. The more spread out the food, the better and quicker the microwave oven will reheat.
Unplug the Microwave
This tip is for the most energy savvy consumers.
As you may know, almost all microwave ovens have standby mode when plugged. The standby mode consumes very little electricity.
If you want to reduce even that, you can unplug the microwave oven after use.
This would not result in drastic energy bill savings, but it can give you a little piece of mind.
Microwave Energy Billing Example
As mentioned earlier, you are billed based on the energy consumption of a device. The energy consumption takes both the rated power as well as the cooking time into consideration
Also recall from earlier that all microwave ovens have Power Level settings whereby you can select the percentage of the total output power for your cooking.
At 100% Power Level
The mentioned microwave would have an energy consumption of 1.7 kWh IF it operated continuously for an hour at full 100% Power Level. In other words it would cost you about 22.42 cents to operate it continuously for an hour (1.7 kWh x 13.19 Cents) at the full 100% Power Level setting.
Alternatively, if you used the same oven for 1 minute at 100% power level, then you would be billed about about 0.37 cents (1.7 kWh / 60 minutes X 13.19 Cents).
At 50% Power Level
If you selected 50% power level, the consumption would be reduced by half in theory. In turn, this would cost you half as much for the same time span.
Hence at 50% power level a microwave oven with 1700 W input power would consume 0.85 kWh (1.7 kWh x 0.5) if operated continuously for an hour.
In other words, instead of being charged 22.42 cents, you would be charged 11.21 cents per hour if you reduce the power level to 50%. This translates to 0.186 cents per minute.
So what is the power consumption of a microwave oven? At an average, the power consumption of a microwave oven is about 1.4 kWh.
It is important to note that you take the input power and not the output power of a microwave when calculating the energy consumption.
In this article we talked extensively about microwave energy consumption, how much it costs to operate, and how you can reduce it.