But Google on Wednesday provided one way to measure its technical prowess: It revealed that Google-designed data centers use "nearly five times less energy" than conventional data centers to power and cool computers.
"We strive to offer great Internet services while taking our energy use very seriously," said Urs Hölzle, Google's senior VP of operations, in a blog post Wednesday. "That's why, nearly a decade ago, we started work to optimize the energy efficiency of our servers and later set out to build the most environmentally sustainable data centers possible. We now believe that Google-designed data centers are the most efficient in the world."
It takes more energy to do a Google search on a personal computer than it does for Google to answer a query, said Hölzle.
"What our data centers do is a very, very effective job at delivering power to the IT equipment, and not using it for cooling and backup," said Erik Teetzel, Google's energy program manager.
Teetzel explained that while all data centers use water for cooling, Google-designed data centers don't use water for chillers, which are a kind of air conditioner. Instead, Google uses cooling towers, which just let the water evaporate without using any power.
Google has long pursued a build-it-yourself strategy to get the most out of its hardware and software. That's why the company uses open source software, so it can customize the code it relies on and control its own destiny.
About eight years ago, Teetzel said, Google began building its own servers, and because the person responsible also oversaw the facilities budget, that led to a focus on data center efficiency improvement and cost reduction.
For Google, being green isn't a promotion gimmick. It's a business edge. "Efficiency is more than just being green," said Teetzel. "Efficiency is about operating a highly competitive business."
In conjunction with Hölzle's revelation, Google has launched a Web site that aims to demonstrate the company's commitment to sustainable computing and to encourage sustainable practices elsewhere. It features information about server efficiency, data center efficiency, water management, and environmentally sustainable practices.
Google claims that before the year's end, two of its data centers will run entirely on recycled water. By 2010, the company expects that 80% of the total water it consumes will be recycled. The company also claims that it recycles or reuses 100% of its servers.
Google isn't going with complete disclosure and providing data center blueprints. "I don't know if we're going to outline a specific road map for everyone," he said. "Doing what we would do wouldn't work for the standard company."
But Teetzel believes that Google is providing enough technical information that other companies can make their operations more efficient and more competitive.