Recently a Harvard University scientist, Alex Wissner-Gross, was quoted in TimesOnLine that each computer search of the internet could produce as much as 7 gram of CO2 (the journalists of TimesOnLine compared that to boiling a kettle of water that would produce about 15 gram of CO2). Google responded that the calculation was not right as an average search would only last about 0.2 second and that that would then equate to about 0.2 gram of CO2. Clarifications later on revealed that Google referred to a one time search hit whereas Wissner-Gross referred to a complete search that encompasses several hits. Further more Google pointed out that the company has several environmental footprint reducing initiatives underway.
But it remains of course interesting to know how much energy the ICT infrastructure needs. It has been suggested that this could be up to 2% of the world’s total greenhouse emissions (comparable to the amount produced by air transportation).
Closer to ourselves: who knows how much energy your PC at home takes up? Well I did not know the answer and I have monitored my PC for a week. I simply hooked up a kWh meter between the outlet and the PC/printer/external HD/scanner assembly. The lucky number is: 6.3 kWh per week. At night I switch the PC off and during day time I put the PC in standby after 20 minutes of idle time. I also compared this figure with my freezer/fridge combination:
- PC 6.3 kWh/week 327 kWh/year
- Freezer/Fridge 38.1 kWh/week 1981 kWh/year
Then also good to know is that the electricity need of an average Belgian family is about 3500kWh per year.
What we conclude from this that indeed PC’s and accessories do require a substantial amount of energy that is not small compared to other household appliances. A critical look at standby regimes and shutting down overnight seems to be wise.
© Copyright John Schmitz
 Recent Gartner report, see reference 1