Unleashing Stranded Power and Cooling Data

Transcription

1 Unleashing Stranded Power and Cooling from New and Existing Data Centers An affordable, five-step approach to addressing power and cooling shortages By Dr. Kenneth Uhlman, P.E. Director of Data Center Business Development Eaton Corporation Executive Summary Global demand for digital information and imagery is rising rapidly, putting severe strain on today s data centers. In response, organizations are making increased use of blade servers and virtualization technologies that allow IT managers to squeeze more processing power into existing floor space, but that also significantly raise power and cooling requirements. As a result, most data center managers now find themselves continually faced with making costly new investments in additional power and cooling capacity to meet their organization s needs. There is, however, a more affordable alternative: Instead of adding new resources, IT and facilities managers can enhance the efficiency of their new and existing facilities instead, freeing up stranded energy and cooling that currently go to waste. This white paper examines the underlying roots of today s data center power and cooling crisis and outlines five steps businesses can take to support intensifying IT requirements economically by removing inefficiencies from their power and cooling infrastructure. Table of Contents Origins of the Power and Cooling Crisis...2 IT Technologies... 2 Other Important Factors... 2 Addressing Power and Cooling Needs Cost-Effectively Establish business goals and objectives Perform a power and cooling audit Establish a monitoring and metering strategy Update your UPS equipment Implement an efficient passive cooling system... 5 Conclusion...7 References...8 About Eaton...8 About the Author...8

2 Page 2 of 8 Origins of the Power and Cooling Crisis Many factors contribute to the pressing shortage of power and cooling that most data centers face at present. Fundamentally, however, the core issue is that today s businesses and consumers have a ravenous and constantly growing appetite for digital information. Consider, for example, these facts: American households consumed an astounding 3.6 zettabytes of information in 2008, according to a study from the Global Information Industry Center at the University of California, San Diego. That s 3.6 million million gigabytes, or 34 gigabytes per person per day. Analyst firm IDC predicts that by 2012 global stores of digital data will reach twice their 2009 level and four times their 2007 level. Also from IDC: There were over 450 million mobile Internet users worldwide in 2009, and there will be more than twice as many by the end of No wonder, then, that organizations in every industry are struggling to meet rapidly rising demand for compute, storage and networking resources. IT Technologies Traditionally, businesses have responded to such pressures by constructing new data centers or expanding existing ones. Yet either approach costs millions of dollars and can take two or more years to complete. Many companies are therefore utilizing virtualization and blade servers to pack more computing power into existing facilities. Virtualization enables a single physical server to support multiple virtual machines, each running its own operating system and applications. This allows IT departments to consolidate underutilized servers onto bigger, more powerful host devices, conserving data center floor space while lowering hardware procurement and maintenance costs. However, precisely because they dramatically increase compute densities, both virtualization and blade servers also place greater demands on electrical circuits and cooling systems than conventional servers do, raising per-rack loads from 5 kw on average to 10, 15, 25 kw or more. Thus, the two most effective strategies for coping with the world s insatiable hunger for information continually leave data centers searching for more power and more cooling. Other Important Factors Of course, technological issues aren t the only ones responsible for today s power and cooling shortage. A variety of additional dynamics also play a part, including these: Outdated power quality equipment: In the 1990s, the average uninterruptible power system (UPS) was about 85 to 90 percent efficient. Today s models, however, routinely achieve 90 to 94 percent efficiency, and in some cases deliver up to 99 percent efficiency. However, with IT budgets stretched tight, many organizations continue to use aging, wasteful UPSs rather than replace them with newer models. Utility incentives: Many electric utility companies offer rebates for energy-saving equipment such as energy-efficient UPS systems, variable frequency drives and lighting control systems that may improve return on investment calculations for inefficient equipment. Misaligned financial incentives: At most companies, the IT department operates the data center but the facilities department pays the electrical bill. As a result, IT managers tend to pay more attention to metrics like performance and uptime than to energy efficiency. Short-term supply chain decisions: Most organizations push the vendors responsible for constructing data centers to complete their work on time and under budget. Consequently, supply chain participants, engineers, contractors and project managers on data center construction projects often make critical equipment selections based solely on short-term considerations like price and availability, ignoring longerterm concerns like efficiency. The end result is a data center that squanders energy unnecessarily.

3 Page 3 of 8 Inadequate metrics: Most organizations today may only guess their energy efficiency. That s because too few companies make use of power metering equipment, which collects the raw data that IT and facilities managers need to compute energy usage with precision. Only by measuring their energy use with precise meters can data centers benchmark their power efficiency against comparable organizations and set realistic efficiency targets. A metric called Power Usage Effectiveness (PUE) can help with this task. Developed by The Green Grid, a technology industry non-profit consortium dedicated to raising data center efficiency, PUE expresses the amount of power used for power quality and cooling by dividing the total power entering an IT facility by the total power used by IT equipment in that facility, as follows: PUE = (Total Facility Power) (IT Equipment Power) Thus, for a data center that consumes 1,000KW of power, of which 400KW is used by IT equipment: PUE = = 2.5 Figure 1: Data center metrics from The Green Grid A related metric called Data Center infrastructure Efficiency (DCiE) expresses efficiency in percentage terms: DCiE = 1/PUE x 100% In the example above, a PUE of 2.5 would translate into a DCiE of 40%, as so: DCiE = 1/(2.5) x 100% = 40% Together, PUE and DCiE provide figures you can use to weigh your power utilization against similar types of data centers, as in the following table:

4 Page 4 of 8 1MW Net IT Load Example Annual Annual MTons Data Center Type PUE DCiE KWHR $.10/KWHR CO2 Internet Tier II Best-in-Class * % 10,599,600 $1,060,000 9,169 Average % 17,520,000 $1,750,000 15,162 Uptime Inst. Tier III Good % 17,520,000 $1,750,000 15,162 Average % 21,900,000 $2,190,000 18,945 Uptime Inst. Tier IV Average % 26,280,000 $2,628,000 22,732 Source: Uptime Institute (2007) * Focus, Vol. 3, Issue 1. Google Data Center (12/08) Addressing Power and Cooling Needs Cost-Effectively Though the figures in the table above are mostly cross-industry generalizations, they highlight an important observation: Most companies run their data centers less efficiently than they could, and far less efficiently than industry leaders. Closing that gap would free up energy and cooling that currently goes to waste, enabling them to get more capacity from their existing power infrastructure rather than adding costly new resources. Indeed, in 2007 the Environmental Protection Agency concluded that by utilizing best practices such as an IT technology refresh, efficient power and cooling as well as metrics and enterprise monitoring, existing data centers could reduce energy consumption 50 percent by Fortunately, any organization can make significant progress towards improved power efficiency by executing these five steps: 1. Establish business goals and objectives Companies sometimes decide they need more power and cooling before asking themselves why. Generally speaking, power and cooling needs increase when processing, storage and networking needs increase. Before embarking on an effort to augment power and cooling capacity, then, organizations should take a close look at the factors driving their increased need for computing capacity. It may be that part of their problem isn t a shortage of power and cooling so much as an excess of underutilized servers, unneeded applications and duplicate data. In addition, be sure to review your firm s long-term IT plans before embarking on a power and cooling initiative. If you will be consolidating data centers or outsourcing your IT operations next year, for example, there s no point in dedicating a lot of time to power and cooling concerns this year. 2. Perform a power and cooling audit Step one in any efficiency drive should be establishing baseline PUE and DCiE measures to track your progress against. And the best way to arrive at those figures is by having a certified power system engineer (PSE) conduct a thorough Power Chain audit of your data center. An Eaton PSE can not only audit your power efficiency but assess the performance and resiliency of your power systems and conduct a comprehensive electrical safety survey as well. 3. Establish a monitoring and metering strategy In addition to calculating your power efficiency, now you must also equip yourself to measure efficiency on an ongoing basis by installing monitoring and metering software. Such systems collect power usage data from across your enterprise. They can also alert facility managers when equipment is in danger of exceeding power or temperature thresholds, identify seasonal shifts in energy demand and project future power requirements based on current usage patterns. A new publication by ASHRAE TC9.9 entitled Realtime Energy Consumption Measurements in Data Centers may provide additional information on this topic.

5 Page 5 of 8 4. Update your UPS equipment As noted earlier, a UPS built ten or more years ago may be 85 percent or less efficient when operating at 40 percent utilization and serving dual-corded servers. That means a data center using out-of-date UPS equipment is wasting 150 kw of every 1,000 it consumes. Worse yet, since most of that 150 kw escapes as heat, dispersing it consumes additional energy to cool it. Replacing outmoded UPSs with late-model equipment offering up to 99 percent efficiency can help you capture most of that wasted electricity and put it to work powering your IT infrastructure. Plus, deploying new UPS equipment may qualify you for efficiency incentives from power utilities, which can help defray your capital expenditures. 5. Implement an efficient passive cooling system Today, most organizations continue to dissipate data center heat by placing computer room air conditioning (CRAC) units around the periphery of their server floor. However, Intel and other data center experts have discovered that when coupled with mismanaged air in the data center, such as mixing of hot and cold air and poor air grill placement, this topology, often results in up to 60 percent of the cooling being wasted. Figure 2 illustrates a legacy data center with volume servers rated 5 kw per rack and 6 percent utilization being replaced by a blade server solution rated 25 kw per rack. This solution may provide more compute capability while decreasing the server, rack and total kw by an order of magnitude. However, while it also conserves floor space, after two rows have been installed the data center is out of power and cooling capacity. Legacy Volume Server Data Center Figure 2: Legacy v. blade server data centers Cooling Tower H2O Pumps Chillers $ 5KW per Rack, 6% Utilization Blade Server Data Center H2O Cooling Tower Pumps Chillers $ 25 KW per Rack, 60% Utilization One way to address these high-density areas in data centers is to use liquid-cooled solutions on the raised floor. However, liquid cooling results in additional costs and risks for the organization. While in-row or overhead liquid-cooled solutions may be a viable option, passive cooling solutions that do not place water on the raised floor may be more cost-effective with less risk for your application. WP April 2010

6 Page 6 of 8 However, liquid cooling solutions and passive cooling solutions both offer advantages and disadvantages, as described in the following table. Cooling Solution Pros Cons In-row or overhead liquid Addresses high-density IT Expensive cooling equipment - Dual chilled water systems Passive cooling Less risk More floor space for IT No water near the IT equipment Greater energy efficiency Adapts to raised or non-raised floor - Leak detection systems Less floor space for IT Costly maintenance contracts Lower energy efficiency Architectural issues such as low ceiling height may arise Architectural issues such as low ceiling height may arise May not be able to handle max IT rack power Figure 3: Data center cooling topologies

7 Page 7 of 8 Many organizations are concerned about introducing water into the IT environment. Liquid-cooled solutions require expensive capital equipment and may be very disruptive in solutions that require retrofitting existing data centers. Long-term maintenance contracts also impact the total cost of these systems. Figure 4: Chimney IT racks Passive cooling systems, whether they utilize chimneys or other enclosed technologies, address the inefficiencies of cooling in the data center and can provide cooling up to 25 kw or more without placing water on the raised floor. Passive cooling systems can be applied in drop ceiling or in return air plenums. If floor space is not an issue, at least in the near term, another solution may be to utilize only a portion of the IT rack to keep the power and cooling density within acceptable limits. Conclusion Attempting to predict the future is notoriously hazardous, but data center managers can be sure of one thing, at least: Processing, storage and networking demands will continue to climb for many years to come. And that, in turn, means that data centers facing power and cooling shortfalls today can expect to confront similar shortages more or less indefinitely. Organizations often attempt to address such shortages by operating legacy data centers or designing new ones with inefficient IT, power and cooling solutions. Likewise, their procurement processes may value incentives to reduce initial costs over solutions that may be more efficient and have a lower total cost of ownership. By updating existing data centers with energy efficient solutions, organizations may be able to postpone or eliminate the need for new data centers. If new data centers are required, whether client-built or outsourced, energy-efficient solutions should be considered for maximum sustainability and lowest longterm costs.

8 Page 8 of 8 References ASHRAE, Real-time Energy Consumption Measurements in Data Centers. Intel, D. Garday and D. Costello, Air-cooled high-performance data centers: Case Studies and best methods, The Green Grid, U.S. Environmental Protection Agency, Report to Congress on Server and Data Center Energy Efficiency, Public Law About Eaton Eaton Corporation is a diversified power management company with 2009 sales of $11.9 billion. Eaton is a global technology leader in electrical components and systems for power quality, distribution and control; hydraulics components, systems and services for industrial and mobile equipment; aerospace fuel, hydraulics and pneumatic systems for commercial and military use; and truck and automotive drivetrain and powertrain systems for performance, fuel economy and safety. Eaton has approximately 70,000 employees and sells products to customers in more than 150 countries. For more information, visit In addition to UPSs, Eaton is your source for a comprehensive range of data center and computer room solutions, including power distribution, power protection, rack enclosures and on-site services.to find out more, visit or call us at About the Author Dr. Kenneth Uhlman, PE, is the director of data center business development for Eaton Corporation, where he is responsible for Eaton s global data center strategy. He focuses on improving efficiency, availability and business service management for data centers, including the convergence of IT and Facilities He can be reached at KennethLUhlman@Eaton.com. Tutorials on demand Download Eaton white papers to learn more about technology topics or explain them to customers and contacts. Maintenance bypass, paralleling, UPS topologies, energy management and more are demystified in free white papers from our online library: