The dishwasher is one of the most time-saving appliances in any modern kitchen. Most dishwashers can make two sink loads of dishes sparkle in an hour or less, all at the push of a button. But it can’t get the job done without a steady flow of electricity — so how much time would it save you if you had to generate all that electricity yourself?
How Many Watts Does a Dishwasher Draw?
Dishwashers definitely save you time and they usually save a good deal of water when compared to hand washing. But since the dishwasher has to power its processes as well as get a little extra work out of the hot water heater, it does use a little more energy than doing it the old-fashioned way.
Dishwashers come in all shapes and sizes, but most residential dishwashers that are designed to fit under the counter draw between 1,100 and 1,500 watts of electricity. For our example, we chose the Bosch SHP65T55UC 500 series, the best fully-integrated model of 2018 according to dishwashersguide.com.
The Bosch model draws 1,300 watts, putting it right in the middle of the typical range, and it has one merciful feature for whoever has to exercise to power it: a 30-minute express cycle.
How Many Calories Power a Dishwasher?
While it would be nice to harness the energy output of our exercise and save it for later, that technology hasn’t arrived quite yet. But we can at least look at our human-power in terms of calorie consumption, which we can then convert to watts.
The energy required to metabolize a single calorie is equivalent to 4.1868 watt-seconds, and a watt-second is the amount of energy required to sustain one watt of electricity for one second. So, let’s find out how many calories it would take to power our 1,300-watt dishwasher for one second:
1,300 watts ÷ 4.1868 watt-seconds = 310.5 calories
How Much Skipping Rope Does It Take to Power the Dishwasher?
To complete our calculations, we have to pick a workout and find out how many METs it produces. The MET, or metabolic equivalent, is a unit of measurement used in calorie calculations. According to the Compendium of Physical Activities, rope skipping comes in at an impressive 12.3 METs, so hopefully our athletes will be able to hop long enough to get those dishes clean.
We’ll also need the weight of the person generating the energy, so we’ll use the Centers for Disease Control and Prevention‘s averages: 88.76 kg for men and 76.43 kg for women.
Let’s start by figuring out how many calories a man and the woman can burn during one hour of rope skipping:
12.3 METs x 88.76 kg = 1,091.75 calories per hour for men
12.3 METs x 76.43 kg = 940.09 calories per hour for women
Next, let’s find out how many calories we need to burn to get through the dishwasher’s express cycle. There are 1,800 seconds in 30 minutes, and our dishwasher needs 310.5 calories per second to run.
1,800 seconds x 310.5 calories = 558,900 calories per express cycle
At 1,091.75 calories per hour, the man would need to skip rope for 21 days, 7 hours, 55 minutes and 48 seconds to burn all 558,900 calories to wash a load of dishes. The average woman would need to keep at it for 24 days, 18 hours, 31 minutes and 12 seconds to do the same.
So the next time you have to hand wash the dishes, remember, it could be worse.
Find out how much you’d have to exercise to power other appliances!