Google has long been conscientious about its energy use and carbon footprint. With the launch of Google Instant — the super fast, interactive new search feature — I couldn’t help but wonder if the search engine giant didn’t just crank up their energy use considerably. A Google spokesperson tells me the company doesn’t know yet whether Google Instant will consume more, less or the same amount of energy as the old search function.
Well, first off, no doubt someone at Google knows the energy consumption difference between Google Instant and the previous search, because the company has to budget its energy bill. Energy usage isn’t something that’s hidden and emerges over time; it’s usually pretty clear what the addition of hardware and software will mean in terms of energy costs. According to last year’s research report from MIT, Carnegie Mellon and Akamai, Google spends over $38 million per year for electricity to power its infrastructure.
I’d speculate that Google Instant does consume more energy than the previous search, but it’s also clear that Google has gone out of its way to try to raise the function of its search in an energy-efficient, and low-capital-intensive way. According to Google’s blog post, Google Instant serves “five to seven times as many results pages for each query performed,” but doesn’t have five to seven times the amount of server capacity.
Google’s new feature computes a search every time a user types a character, and the average query length is about 20 characters, according to Google engineer Ben Gomes. Using AJAX, those new results are being delivered to the page with constant communication between the web client and the server, so the user doesn’t have to refresh. These things take energy to deliver.
So what did Google do to prepare for Instant? Google says it did increase its back-end capacity, so that likely means more hardware that’s consuming more energy. How much more? Google doesn’t say, but the company also did other non-hardware based tweaks, like revising its caching system to handle the new requests and optimizing page rendering. In this Register report, Google talks more about some of the data base upgrades.
There’s been a lot of talk about how much energy a Google search query consumes. Google itself reported that, roughly speaking, a Google search query consumes about 0.0003 kWh, or 1 kJ of energy per search. That’s tiny, but given Google performs more than a billion search queries a day, it adds up to a lot of energy consumption. If that per-search energy consumption is jacked up just a bit, it would have an impact on the company’s overall energy consumption. I’m not sure how much, but I’d love to see Google do this calculation.
This isn’t to say that Google hasn’t been a leader in data center energy efficiency, carbon footprinting and, most recently, clean power. In addition, as Google has previously said, having instant access to information often replaces the need to expend energy to find that information in other less energy-efficient ways — like driving to the library — and many think that the Internet’s efficiency gains displace its overall energy use. Still, it would be interesting to see how much more energy Google is willing to consume to make search speedier and more interactive.
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