How much electricity does a dishwasher use? To get a suitable answer for this, it is important to have a backstory of where dishwashers started.
The first three dishwashers to ever exist were a mechanical one by Joel Houghton in the 1850s, a steam-powered one by L.A Alexander in 1865, and a rotary dishwasher by George Butters in 1866. The first electrical dishwasher only came into existence in 1886 and was invented by a woman, Josephine Cochrane.
Tired of the poor state of her expensive china while being hand washed by her house servants, Cochrane, the wife of a wealthy politician, decided to come up with an electrical appliance that could perform the task more diligently and efficiently. Above all, the machine needed to handle her delicate china with care.
In the 1950s, her device gained traction among the American household and has been growing since then. Over 68% of Americans have and use a dishwasher in their houses. Of this, 54% use it at least once a week.
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We shall attempt to answer the aforementioned question in this article. While on the same note, it is imperative to consider the benefits of using a dishwasher to hand washing.
How Much Electricity Does a Dishwasher Use?
Dishwashers typically consume electricity within the range of 1200 to 2400 watts, with an average energy usage of approximately 1800 watts per cycle. Assuming a 1200-watt model and a one-hour load time, the energy consumption would be 1.2 kilowatt-hours (kWh).
However, your dishwasher's energy consumption will depend on various factors, which shall be discussed below. Modern dishwashers come with an Energy Guide label which gives you an approximate value of your dishwasher's annual energy consumption (which can then be used to derive monthly costs).
The following steps will help you calculate your dishwasher's base electricity consumption, and help you save money on your electricity bill in the long run.
How to Calculate Your Dishwasher’s Base Electricity Usage
The best thing about technology and changing times is that these figures - absolutely impossible to obtain years ago - are now at the tips of our fingers. If you want to know how many units of electricity your dishwasher generally uses, use the following formula:
Energy Consumption = Dishwasher Wattage x Average Time Per Wash Cycle
Dishwasher wattage refers to how many watts your dishwasher uses. You can find this information on your dishwasher's manual or somewhere on the dishwasher itself (probably the back). You can keep note of this number because it is a constant. This is why you should be careful when purchasing a dishwasher; too high a dishwasher wattage may actually be energy-inefficient. In our case, we shall assume that our dishwasher uses 1200 watts.
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The next unit you should have is how long each cycle takes. If your dishwasher takes 1 hour to run all three cycles, include this figure in the formula.
For this example, then:
Energy Consumption = 1200 x 1 = 1200 watt-hours (Wh)
To convert this into kilowatt-hours (kWh), divide 1200 by 1000 = 1.2 kWh per cycle.
If your dishwasher runs once per day, then you use 1.2 x 7 = 8.4 kWh per week.
Next, to calculate your dishwasher's base electricity usage;
Base Electricity Usage = Energy Consumption per cycle (kWh) x Number of Cycles Per Day
In our case, our dishwasher uses 1.2 kWh per day or per cycle (since we use one cycle per day).
Assuming that the price of a unit of electricity (kWh) is $0.154, then for our household, we spend about $0.1848 daily on dishwasher electricity usage, which is about $1.2936 per week. This is not too bad, considering the average dishwasher consumes 1800 kWh and incurs $1.17 weekly (where each kWh is $0.13).
Factors That Affect Your Dishwasher’s Electricity Consumption
Not all dishwashers have the same power consumption. You need to make informed decisions about your dishwasher purchase to save money that would have otherwise been wasted. Moreover, knowing which modes or settings use more electricity helps you stay in the know so that you will use the ones with less actual energy consumption.
We have compiled the following factors that affect how much electricity a dishwasher uses:
1. Energy Efficiency
In 1992, the US Environmental Protection Agency (EPA) set up a voluntary program called Energy Star, which promotes energy-efficient products and practices. The aim was to enable consumers to save money and energy while at the same time being environmentally conscious. EPA published and continues to update strict energy protocols to be followed.
Household appliances such as dishwashers use a lot of electricity to run. EPA sets criteria that such appliances should meet to be termed an Energy Star dishwasher. Some of the criteria such a dishwasher has to meet include:
- Energy consumption. A dishwasher's different wash cycles should meet set minimum efficiency levels. Ideally, an Energy Star dishwasher should consume less than 270 kilowatt-hours per year (translating to 740 watts per day).
- Performance standards. Energy Star-certified dishwashers should produce cleaner (faster or better) than older, non-efficient dishwashers.
- Water consumption. Typically, Energy Star-rated dishwashers must use at least 5 gallons of water per cycle (less is preferred).
- Noise. Yes, EPA requires that Energy Star dishwashers should function under minimum noise levels.
2. Dishwasher Model or Brand
Truth be told, some brands are more energy-conscious than others. Whether it is their Corporate Social Responsibility attempts or their passion for reducing the carbon footprint, you will know an energy-conscious organization from a mile away.
Some of the most trusted energy-efficient dishwasher brands include BOSCH, LG, Miele, Whirlpool, and KitchenAid. For instance, BOSCH dishwashers have an AquaStop Leak Protection feature that reduces water wastage through leaks. Miele engineered a 3D+ cutlery tray that maximizes the reach of all utensils placed on the tray, thereby reducing the wastage of water and energy.
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Before you make the big purchase, research avidly about the pros and cons of each brand, and weigh them against your requirements. Shop for reputable brands with a clear energy plan that puts the planet first.
3. Load Size
Waiting for dishes to pile up before washing them is not entirely bad. If you think about it, you'll be pushing your dishwashing needs for a select time, say after dinner, which effectively saves you time and resources that could have been spent washing dishes after every meal.
A very important point to note is that regardless of the load size, whether partial or full load, the dishwasher will expend the same amount of energy. It is, therefore, prudent to only turn on your dishwasher when it is on full load.
4. Dishwasher Size
Naturally, the size of your dishwasher affects your load size. A larger dishwasher will accommodate more dishes and will often fit full loads as compared to smaller ones.
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On the other hand, larger dishwashers will use more water than smaller ones, thereby taking up more resources. Using a water heater to heat all this water uses up high amounts of electricity, which may run up your electric bill. Also, bigger dishwashers have bigger motors, which means more power consumption.
In general, larger dishwashers are less efficient than smaller ones, as they utilize larger amounts of energy and high water usage to clean dishes. If you really need a large dishwasher based on your needs, do your research to ensure you are getting the most efficient dishwashers out there. A countertop dishwasher is compact, space-efficient, and convenient, making it a good place to start.
Before you purchase a dishwasher, consider:
- The size of your household
- The number of dishes you use
- How often do you cook and eat from home
- The size of your pots
5. Wash Cycle
The different wash cycles that your dishwasher has affects exactly how much energy it uses. Most modern dishwashers have three wash cycles: pre-wash, main wash, and rinse. The first stage, pre-wash, gets your dishes ready for the main cleanse by spraying warm water to remove loose stains.
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The next step is a more intense cleaning process and involves the actual washing of dishes with soap and hot water. The last step is where the dishes are rinsed with warm water to remove detergent.
Inasmuch as modern dishwashers are more energy-efficient than the average dishwasher, this comes at a compromise. Sometimes, the wash cycles may be prolonged. For instance, the main wash may take from 20 minutes to an hour and may be repeated severally during the cleaning process. So, in this case, the main wash generally may run up your electric bill more than the pre-wash or final rinse cycles.
Pro Tips to Minimizing Your Dishwasher’s Energy Usage
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The following tips help in conserving energy in your dishwasher:
- Open your dishwasher door after washing to allow the dishes to air dry.
- Avoid overcrowding your dishwasher while at the same time minimizing partial loads.
- Use the most appropriate cycle or mode depending on how dirty your dishes are.
- Pre-wash (this involves scrapping loose dirt and food particles) your dishes in the sink before loading them into the dishwasher.
- Schedule your dishwasher to start during off-peak hours, when energy rates are lower if your dishwasher has the delay start option.
- Regularly clean and maintain your dishwasher to optimize energy efficiency.
- Preferably, go for an energy-efficient model such as an Energy-star certified dishwasher that uses less electricity and therefore incurs less utility costs.
Using a dishwasher helps to ultimately save energy, water, and energy, as compared to hand washing dirty dishes Furthermore, it is very convenient, especially if you lead a busy lifestyle.
Ultimately, the answer to the original question, "How much electricity does a dishwasher use?" the answer is relative. The amount of electricity your dishwasher uses is objective and depends on the dishwasher model you use, its power rating, and if it's ENERGY STAR-certified. Your monthly cost of dishwasher electricity usage will greatly reduce if you pick the right model.