A while ago the 'news' went around that Google could supposedly cut the energy consumption of millions of monitors by changing their website background to black. It turned out only to be true for old CRT monitors, and a bit silly all in all. But I sometimes do a couple of hundred Google searches a day, nevermind the other web-based services I use that are off consuming power on my behalf, and Rolf's post reminded me about an idea I had that I think could really work.
What if Google replaced the "I'm Feeling Lucky" button with one that said "I'm Feeling Patient" instead, and then waited for a convenient moment to perform my search instead of performing it instantly? Would they (could they) reduce the number of servers needed for search if they did that? And will there ever be a point where increased efficiency doesn't get used up by doing more instead of being used as an opportunity to cut back?
I know Gavin Bell has been thinking about these ideas too, wondering how to measure the energy consumption of web services in general, including the effects of mod_gzip on the power consumption of nosy routers that inspect packets at every hop. I wonder about the environmental cost of indexing all those mailing lists I leave archived and unread in my GMail.
Clearly some of these things pale into insignificance when compared with the environmental impact of air travel, long commutes, badly insulated homes, old power grids, etc. but I wonder if they start to be worth thinking about at a company operating on Google's scale.