Referring again to the power consumption of “stand-by” appliances discussed earlier, I recently stoborrowed a WSE Wattmeter, made by Messtechnik Schaffhausen GmbH, from our laboratory, and measured the power consumption of the few appliances we have at our place after our recent move.

• Sony stereo player: 6 W.
• Aquarium, 60 L: 100 W with lighting turned on, 20 W with only filter, air pump and heater.
• Philips TV: 8 W on standby, 130 W when turned on.
• Philips DVD: not measurable on standby(!), 17 W when playing.

We have now decided to turn the TV completely off when not in use, which saves us 17.5 swiss francs per year. The Sony stereo can unfortunately not be turned off unless I install a mechanical switch.

I was rather surprised to learn that the lighting on our aquarium required about 80 W, when the fluorescent lamp was only rated at 15 W. I even went to a hardware store to buy a new one, only to discover that the power consumption did not improve. Then I realized that the 10+ years old ballast was almost certainly the culprit, accounting for the missing 65 W. That will be for the next visit to the hardware store…

The BBC carries a story on the energy waste represented by household appliances kept on standby mode instead of being switched off. The UK alone wastes enough energy to send the population of Glasgow on a return flight to New York. The problem is that contrary to what most people (including me) believed, keeping an appliance on standby mode doesn’t save that much energy. From the article, some television sets run at about two-thirds consumption when on standby mode, rather than at just a fraction.

We’ve seen a similar problem in our lab. One of our printers, a Xerox Phaser 8200, used to be left on standby over the evenings and the weekends. Out of curiosity we once measured the printer’s consumption when under standby and found about 150 W, about the same amount of energy needed to keep two lightbulbs glowing. Let’s say nobody uses the printer between 6 pm and 8 am (14 hours), and you are left with a daily bill for about 2 kWh wasted. Under very optimistic assumptions, this is about the energy produced by two square meters of solar panels in Lausanne on a sunny day. Or to put it another way, at 11 swiss centimes per kWh during non-peak hours (roughly what we pay at our place in Geneva), it translates to 73 swiss francs per year.

Sure it irritates me to have to wait for warm-up when I send a print job to the printer in the morning. But if it were “my” money, would I pay that amount per year because I cannot wait for five minutes? Or because I cannot bring myself to remember to switch on the printer on when I arrive in the office? (The printer sits precisely on the way to my office.)

Update: I learned from some educational flyers in our institute that Europe requires the equivalent of six nuclear reactors just to keep devices on standby, or even switched off because of the inefficiency of some transformers.