alt Hacker News> But for obvious reasons I could never dispute them.
I'm sorry, I never worked in a data center nor lived near one, what's the obvious reason you couldn't dispute them? My only guess would be that Google really wanted to keep the amount of usage secret, but that'd only make sense if it was higher than expected not lower.
Google never wanted to share details about their datacenters because they thought (think?) their power efficiency was a competitive advantage. So it'd be lower than you expect.
Also, they didn't want you to be able to guesstimate how many machines / computing power they had, for similar reasons.