Digital power meter

Power consumption @home

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At my employer, an IT business, we are quite aware of energy consumption. Now, I wanted to know how much energy my home office, and other home appliances, do use. Here’s some of the results.

Beforehand, I need to note that electrical power is measured in watts [w], and electrical energy (or work) is measured in watt-seconds [ws] (or more often kilo watt-hours [kWh]). Thus, energy is the amount of power consumed for a certain period of time. That is what you actually pay for, the amount of energy.

Currently, where I live, the price for one kWh is about 30 Swiss cents. For perspective, when drawing one watt continuously over the course of one year, this costs about 2 Swiss francs.

Home office

I use a quite simple setup with an older Lenovo ThinkPad X1 Yoga (1st gen) laptop (with Ubuntu Linux), and 2 external monitors, connected via a docking station.

home office setupMy home office setup.

This home office setup uses around 63 watts, continuously, when using the internet with a video or remote desktop stream. Interestingly having the screens with bright content, as opposed to dark content, makes a difference of a few watts. So an 8-hour day in the home office costs about 15 Swiss cents.

To connect to the internet, I use, a FRITZ!Box 6842 LTE mobile router. This router consumes around 4 watts, continuously. This is remarkably low.

Household devices

  • The freezer, at -18°C, uses 42 watts, on average. That’s about CHF 5.- per month.
  • My quite old USB charger, on standy (no device connected), actually uses 0 watts. I can keep it connected all the time to the socket outlet.
  • The cheap 10 meter LED strip uses about 17.4 watts, having fully red light. Interestingly, having a green or blue color only uses about 9.5 watts. When turned off (actually in standby with the remote contol unit), it uses virtually no energy.
  • During brewing, the coffee machine uses around 1400 watts, however, actually pouring a single coffee uses about 0.014 kWh. That’s a less than half a cent per coffee.
  • The dishwasher, when not in use, does not use any power. During heat-up, up to 2030 Watt is consumed. For the whole “eco” program, the dishwasher uses about 0.598 kWh, which costs about 20 cents. This is above, but reasonably close to, the officially claimed value by the manufacturer of 0.534 kWh for this mode.