One Google-search or one hour of light?

Last saturday I had a chat with one of the McKinsey Risk Managers. We were talking about our weekly travel schedules, waste of time and energy and about were we would expect first real impacts of the financial crisis, when he mentioned very interesting thoughts Mc Kinsey uses in their risk assessments: what’s the environmental cost of using online applications? We don’t have to pay directly for a search in Google, but somebody has to pay for it, so somehow the costs will come back to us…
The average energy consumption for a search is said to be the same amount a low energy lightbulb needs in an hour. And the white screen uses much more power then a black or darker screen would need.
And a Second Life-Avatar (I did not think of Second Life for almost a year now…) is said to consume more energy per day then an average real life human.

I’m not quite sure what to do with these figures, but they definitely make me think.