In an afternoon chat today at Green:Net, Google Green Energy Czar Bill Weihl explained that the future of data center efficiency will not come from improved data center designs themselves, but from more-efficient hardware and cleaner sources of energy.
The reason is pretty simple: data centers like those Google is building are so much more efficient than previous generations’ data centers, that it’s difficult to improve much. It used to be, he explained, that every watt of computing within a data center correlated with a watt of energy used for cooling and other purposes, meaning that the overhead costs of computing were 100 percent of the cost of computing. Now, good data centers like Google’s and Yahoo’s are down to 20 percent overhead, and it doesn’t appear they can go much further, at least not in the near future.
That’s way, Weihl explained, it’s time to look at more-efficient hardware — a trend that has going on for years and where improvements are happening on more of Moore’s Law type of pace — as well as to green energy sources. Google, for example, just bought 100 megawatts of wind power from a location about 180 miles from an Oklahoma data center it operates. It did the same thing last year in Iowa. As long as the energy is on the same grid, it can be used, he explained, so data center operators don’t need to look for clean energy right next door. Going forward, Weihl thinks it will be up to large data center operators to do their part to stem clean energy by helping get more of it on the grid.
However, as Yahoo’s Director of Climate and Energy Christine Page pointed out, many organizations building data centers still can benefit from taking advantage of the new efficient designs pioneered by companies like Yahoo and Google. She points to Yahoo’s “chicken coop” data center near Buffalo, N.Y., as en example. Not only was the modular design cheap to build, but it was completed in less than six months and uses 40 percent less energy than standard data centers and 90 percent less water because it’s cooled using outside air 99 percent of the time. Data centers might not get much more efficient in design than this, but adoption of these designs can pick up.
Both panelists agreed on one thing for certain: efficient data centers are important because they will be asked to take on more responsibility as we rely more on cloud computing. Page said that data centers account for approximately 2.5 percent of energy consumption, but they help reduce far greater amounts of greenhouse gases than they emit because data centers enable smart grids and other energy-efficiency efforts. Or, as Weihl put it, it takes a lot less energy to do a video conference than it does for a handful of people to hop on a plane and fly to a meeting.
Weihl and Page also shared their thoughts on the limited effectiveness of Power Usage Effectiveness (PUE), a popular method of gauging data center efficiency. Both noted that while it’s a decent jumping off point, other considerations such as carbon emissions, water usage effectiveness and energy sources need to be considered when determining how green a data center really is.