In a house full of energy hogs like a furnace, air conditioner and hot water heater, sometimes we overlook opportunities to cut back on utility costs that are hiding right under our noses. One appliance that seldom comes to mind when seeking to reduce electricity consumption is the dishwasher. This useful piece of equipment does use a decent amount of energy, however – after all, its main by-product is heat, which takes a substantial amount of power to produce. Read on for an eye-opening exploration of the question of just how much electricity does a dishwasher use.
Dishwashers frequently conceal their true energy consumption since the machine doesn't actually use very much in the way of electricity itself. The pump and control electronics require about 1200 watts, about the same as a blow dryer. Unless the appliance has its own onboard heater, which adds quite a bit to its power demands, that's it. The reason that the dishwasher is able to get away with such a low power profile is because it piggybacks off another one of your household appliances for as much as half of its energy consumption – the hot water heater.
Dishwashers need piping-hot water to do their job effectively, and that water has to come from somewhere. The gas or electricity that the water heater needs to supply the dishwasher should, by rights, count toward the dishwasher's total energy consumption. How much energy is required depends on the amount of water the appliance needs to clean the dishes, which in turn depends primarily on when the dishwasher was manufactured:
Take the estimates above as a general guideline, not set-in-stone figures. To provide a true estimate of how much energy a dishwasher uses is tricky, since the amount of power used by your model will vary widely depending on the manufacturer's design and which cycles you choose to run. Different settings for soil level and the type of dishes in the load will affect variables such as the water pressure and amount of water. You may also have an option for heated drying, which essentially doubles the base electrical cost to produce another round of heat. So, your mileage may vary, but by using the average consumption rates we can get an idea of how money the dishwasher adds to your monthly utility bills.
A dishwasher's base electricity usage is pleasantly inexpensive. For a 1200-watt model and a load time of one hour, you use 1.2 kilowatt-hours (kWh), which is about 12 cents per load on a 10 cent per kWh electricity plan. If you run the appliance five days a week, you'll end up paying just $2.40 each month for basic electricity consumption.
Don't forget about the hot water, however. Assuming we've got an inlet temperature of 68°F and a target temperature of 120°F, the numbers work out as follows:
How to Save Money When Using Your Dishwasher
You do have opportunities to whittle down the amount of money you spend on energy for your dishwasher and other kitchen appliances. Try out the following tips to keep your power usage to a bare minimum: