Let’s talk about data centers. As you may or may not know, data centers have begun to account for a greater percentage of national energy usage—due in large part to our increasing dependence on their services in our private and public lives. According to a 2007 report by the USEPA on server and data center efficiency [read article...], “During the past five years, increasing demand for computer resources has led to significant growth in the number of data center servers, along with an estimated doubling in the energy used by these servers and the power and cooling infrastructure that supports them.”
Here are some facts about the current state of data center energy demand, courtesy of the EPA’s report:
* It is estimated that this sector consumed about 61 billion kilowatt-hours (kWh) in 2006 (1.5% of total US electricity consumption) for a total electricity cost of about $4.5 billion.
* This estimated level of electricity consumption is more than the electricity consumed by the nation’s color televisions and similar to the amount of electricity consumed by approximately 5.8 million average US households (or about 5% of the total US housing stock).
* Federal servers and data centers alone account for approximately 6 billion kWh (10%) of this electricity use, for a total electricity cost of about $450 million annually.
* The energy use of the nation’s servers and data centers in 2006 is estimated to be more than double the electricity that was consumed for this purpose in 2000.
* One type of server, the volume server, was responsible for the majority (68%) of the electricity consumed by information technology (IT) equipment in data centers in 2006. The energy used by this type of server more than doubled from 2000 to 2006, which was the largest increase among different types of servers.
* The power and cooling infrastructure that supports IT equipment in data centers also uses significant energy, accounting for 50% of the total consumption of data centers.
* Among the different types of data centers, more than one-third (38%) of electricity use is attributable to the nation’s largest (i.e., enterprise-class) and most rapidly growing data centers.
As the EPA’s report points out, the effects of data center energy usage are significant and far-reaching, including: “increased energy costs for business and government, increased emissions, including greenhouse gases, from electricity generation increased strain on the existing power grid to meet the increased electricity demand, and increased capital costs for expansion of data center capacity and construction of new data centers.”
So what does any of this mean for the average citizen? Plenty when you take into account the fact that a lot of those data centers are devoted to one particular type of activity: social networking.
With those EPA statistics in mind, two of the biggest social networking sites—Facebook and eBay—have both begun to actively pursue data center energy efficiency.
For Facebook, greater energy efficiency has been achieved primarily by fine tuning airflow at their 56,000 square-foot data center in Santa Clara, CA. A mix of cold and warm air circulation was ultimately controlled using cold aisle containment to keep cooled air inside the server aisles. By preventing the escape of cold air, the company was able to scale down its computer room air handlers (CRAHs) by 15 units while simultaneously increasing the average temperature of the CRAH inlets to 81 degrees—reducing the total energy draw of the facility by 114 kW. With its current data center drawing a smaller amount of electricity for its needs, Facebook’s next step involves the completion of its latest data center in Prineville, OR, which the company touts will be “one of the most energy-efficient data centers” in the country.
Over at eBay, a similar energy usage analysis also revealed that cool air lost through poor air circulation and insulation was adding to the company’s data center energy usage. The company was able to reduce total power consumption by installing blanking panels to prevent cold air seepage and worked with the supplier of its universal power supply systems to reduce the excess capacity of those systems. Overall, eBay’s efforts resulted in a reduction of power consumption and carbon emissions by 16% and a total IT power load increase of 50% (achieved in part by the additional of servers made possible by the decreased power load).
Like Facebook, eBay is not resting on its laurels and has instead announced the opening of a new—and even more energy-efficient—data center. The company’s Topaz data center opened in May of this year in Utah. According to eBay, this new data center includes so many energy-efficient features that it costs less to operate (about 50% cheaper than other, similar data centers) and has achieved a power usage effectiveness (PUE) rating of 1.4.
Facebook and eBay are not alone when it comes to improving data center efficiency. In fact, as we’ve highlighted in the pages of our magazine, data centers all over the country have reduce consumption and increased efficiency by implementing a variety of onsite power and energy management systems, including HVAC optimization, onsite.
So what do you think? Does the latest effort by the Green Grid and the EPA (along with other government and industry organizations) promote “global data center energy-efficiency metrics” based on the PUE rating make sense? Is the PUE rating broad enough in scale to account not only for all the different types of energy use at a data center facility, but for all the incremental—but important—efficiency upgrades that can make a relatively big difference? And what about the big picture? After all, shouldn’t the overall “energy footprint” of data centers take into account the many ways in which their increased capacity has led to reduction in the need for other resources: With cloud computing and the a handful of “virtual” resources it makes possible (e-mail, online banking, webinars, etc.), the cost of personal, business, and social networking—of connecting—has never been cheaper.