Google’s recent decision to reveal how much energy its data centres use—220 million watts, or about one-quarter the output of a nuclear reactor, according to a New York Times calculation—is being billed by the Mountain View, Calif.-based company as a small price to pay for the convenience of having billions of Web pages at your fingertips, not to mention funny YouTube videos. And it probably is. But the rare disclosure (Google had previously feared giving rivals clues about its internal operations) has also highlighted the degree to which the Internet is not necessarily the “free” service most people think it is. All that information comes with a cost. While the numbers sound big, Google claims the actual cost per user is actually tiny. It says the environmental impact of 100 searches is the same as running a laptop for an hour or turning on a light bulb for 28 minutes. Three days of watching YouTube? That’s the same as manufacturing, packaging and delivering a DVD. However, Google’s accounting of the cost of using Gmail for a year appears a touch self-serving: “less than the energy required to drink a bottle of wine, stuff a message in the bottle and toss it in the ocean.” Is that how we’re supposed to imagine a Google-less world?