A power guzzler is not a device with a fixed name. It is any appliance that needs a lot of power or runs for a long time. If you want to know where electricity is really used at home, look less at the impression a device makes and more at its power draw, its running time and its efficiency class. This guide shows which appliances stand out in the sources and where the figures are outdated or incomplete.
Short answer: The largest consumption usually comes from appliances with high power draw, such as an instantaneous water heater (Durchlauferhitzer), which a brochure by the Verbraucherzentrale NRW gives as around 1,300 kWh per year. For fridge-freezer combinations, a lower efficiency class can cost more than 50 euro a year according to the same 2018 source. The figures come from a brochure dated May 2018 and are example values from that year, not current measurements. Last updated: November 2026.
The most important points in brief
- A device’s consumption results from its power draw and its operating time, not from the impression it makes.
- According to the brochure (2018), an instantaneous water heater reaches around 1,300 kWh per year at ten minutes of operation a day, the highest annual value in this overview.
- The 2018 brochure names a difference of more than 50 euro a year between class A+ and class A+++ fridge-freezers, based on the electricity price of that time.
- Standby consumption is small but adds up over the year, because the device draws power continuously.
- For many appliances the brochure names only notes rather than annual values, which matters when you compare.
- For your own calculation, the formula in the guide on electricity costs helps (in German).
What makes a device a power guzzler?
A device uses electricity for two reasons: it has a high power draw, or it runs for a long time. A kettle draws a lot of power but is only in use briefly. A router draws little power but runs around the clock. Both cases can weigh differently on the annual bill, which is why it pays to look at both quantities.
In its brochure, the Verbraucherzentrale NRW describes saving electricity in the household with power values and notes on use. Some individual appliances receive concrete annual values there, others only general statements. These differences determine how reliable a list can be.
Which appliances stand out?
The table below summarises the information in the brochure. The values date from May 2018 and have not been updated. The efficiency classes named refer to the energy label of that time and do not have to match the label of today’s appliances. For a specific appliance, the information on its own label and the manufacturer’s data sheet count. Cost figures rest on the electricity price of 0.29 euro per kWh that the brochure uses for its calculation.
| Appliance | Figure in the brochure | Note |
|---|---|---|
| Instantaneous water heater | around 1,300 kWh per year, almost 380 euro at 10 minutes of operation per day | Highest annual value in this overview |
| TV, PC, printer, router | 590 kWh per year, 170 euro in a four-person household | Group value, no split per device |
| Fridge-freezer | class A+ can cost more than 50 euro a year above class A+++ | No total consumption named |
| Dishwasher | class A+++ uses around 30 percent less power than class A | Percentage without annual value |
| Kettle | power draw of around 2 kW | Consumption depends on how long it runs |
| Standby | 0.5 to 3 W, older models up to 10 W or more | No annual values named |
The table shows how differently the figures are given. Concrete orders of magnitude exist for the instantaneous water heater and for fridge-freezer combinations. For fridges, washing machines and dryers the brochure mainly offers notes on use without annual values. The list is therefore an orientation, not a complete ranking.
Why standby consumption is underestimated
According to the brochure, standby devices usually draw only 0.5 to 3 watts, and older models up to 10 watts or more. That sounds little, but because it applies for 24 hours a day and 365 days a year, it adds up. The source gives no annual values for standby, so you should calculate the amount yourself rather than adopt a number.
Typical standby devices include televisions, chargers, printers and routers. A switchable power strip makes it easier to cut these devices off the mains when they are not in use. Many households do this as a matter of habit.
How do you find out what your device consumes?
The first place to look is the rating plate, which usually states the power in watts. The EU energy label shows the efficiency class and often an annual consumption. Neither replaces a measurement, but both provide a reliable basis when you compare appliances.
If you want more precision, a plug-in power meter can show the actual power draw over several days. This is particularly useful for appliances whose use varies strongly, such as washing machines or dryers.
Why use can matter more than the appliance
An efficient appliance that runs constantly can use more electricity over a year than a less efficient one that is rarely in operation. For this reason, the efficiency class alone is not enough. Settings and use also influence consumption. The brochure gives mainly general notes on these points, for example on the temperature of cooling appliances.
For washing machines and dryers, the source mainly offers percentage notes on use and no annual values. If you keep an eye on the number of wash cycles or the drying time, you can judge your own consumption better than with a general list.
What to check when comparing new appliances
Compare appliances with similar equipment and capacity, so that the annual consumption is meaningful. The energy label shows the efficiency class and, depending on the appliance, an annual consumption. It is also important to estimate how long the appliance will run and how often you use it, because that determines the actual amount on your bill.
A purchase should also follow your needs. A larger appliance does not automatically consume more if you use it sensibly, but it can draw unnecessary power if you rarely fill it. Weigh this against your daily routine.
Frequently asked questions
Which appliance uses the most electricity in the household?
According to the brochure, the instantaneous water heater has the highest annual value named, at around 1,300 kWh per year. The figure applies to operation of 10 minutes per day and dates from May 2018. Whether it still holds for today’s appliances cannot be derived from the source alone.
Is it worth replacing an old fridge?
The brochure names a difference of more than 50 euro a year between a class A+ and a class A+++ fridge-freezer combination. The figure dates from 2018 and applies to the classes and electricity prices of that time. Whether a replacement pays off depends on price, use and remaining service life. This guide does not give a blanket recommendation.
How do I calculate an appliance’s consumption?
With the formula from the guide on electricity costs, you multiply the power by the operating hours and divide by 1,000 to get kilowatt hours. You then apply the price per kilowatt hour separately, for example the value from your electricity contract.
Is standby really relevant?
For a single device the amount is small. Several standby devices together can become noticeable. The brochure names no annual values for standby, so your own calculation is the more reliable route.
How to proceed now
- Note the power of your largest appliances from the rating plate or the energy label.
- Estimate the daily operating time and check it against a typical day.
- Calculate the consumption per month and apply your electricity price.
- Check standby devices and decide which ones you cut off the mains when not in use.
Related guides
- Climate, energy and costs 2027: The overview for tenants and students
- Calculating electricity costs: From appliance to monthly amount
- Saving Electricity as a Student: Energy and Utility Costs
- Grid fees 2027: What the reduced subsidy means for electricity
Sources: Verbraucherzentrale NRW: Strom sparen, Spartipps, brochure, status 05/2018 (in German).
Last updated: November 2026. This guide is general information, not individual advice.
