ENERGY EFFICIENCY MEASURES IN JAPAN: CASE STUDIES

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1 ENERGY EFFICIENCY MEASURES IN JAPAN: CASE STUDIES EDITORS: Akiko Abe, NEC Eiji Taguchi, Intel Makoto Karaki, ITOCHU Techno-Solutions Miho Kato, ITOCHU Techno-Solutions Yoshihiro Fujie, IBM Japan

2 PAGE 2 Executive Summary The Green Grid (TGG) is a global consortium of end-users, policy-makers, technology providers, facility architects, and utility companies dedicated to enhancing resource efficiency in data centers and business computing ecosystems. This white paper aims to help domestic data centers improve their energy efficiency activities by providing case studies about successful energy efficiency projects throughout Japan. These case studies take into account situations such as geography, regulations, culture, and operating management standards. In the decision-making process for which projects to highlight, importance was placed on actual results that had been observed in the process of practical demonstration. In addition to three case studies that won the first Most-Improved Data Center Energy Efficiency Award Japan for 2010, this white paper introduces other case studies that demonstrate fully developed plans for improved energy efficiency that deal with situations native to Japan.

3 PAGE 3 Table of Contents I. Data Center Award Winners... 4 Grand Prix Award: Hitachi, Ltd Improvement Activities Based on Visualization of Operation Status... 5 Performance Award: Fujitsu Limited... 6 Process Improvement Based on Continuous Visualization of Energy... 6 Special Award: IDC Frontier, Inc PUE Improvement Utilizing External Air for Large-Scale Data Center... 8 II. Facility Architecture Case Studies... 9 Internet Initiative Japan, Inc.: Next-Generation Modular Data Center Hitachi: Green Solutions with a Modular Data Center III. Electricity and Cooling Case Studies NTT Facilities, Inc.: Production Proof-of-Concept Study of the HVDC Power-Distribution Method AT ToKyo (@TOKYO): Air Conditioner Efficiency with a Thermal Storage System ITOCHU Techno-Solutions Corporation: Power Load Equalization with Sodium-Sulfur Battery System IV. Data Center Operation Case Study NEC: Use of Energy Management System V. Conclusion VI. Acknowledgements VII. About The Green Grid... 25

4 PAGE 4 I. Data Center Award Winners In 2010, The Green Grid established data center awards ( Most-Improved Data Center Energy Efficiency Award Japan ) to highlight those organizations that effectively improved the energy efficiency of their data centers. Award criteria include: Use of quantitative evaluation criteria (such as power usage effectiveness [PUE ]) Presence of organization-wide strategic goals to reduce energy consumption Establishment of a plan for concrete action to reduce energy Continuous energy reduction activities and quantitative assessment of the results Publishing of results and support of industry-wide improvement activities The data center award-winners in this white paper are achieving these criteria. To be successful in their energy efficiency efforts, award-winning organizations have three aspects in common: they consider energy efficiency a strategic corporate initiative; they leverage PUE metrics, continuously monitor metrics, and share results; and they take tangible steps toward improvement. Energy efficiency as a strategic corporate initiative For an organization to make effective gains in data center energy efficiency, it is important to have top-level executive sponsorship promoting improved data center efficiency as an important issue. One key success factor that award-winning organizations have in common is the establishment of objectives for data center energy savings as an organization-wide goal. These organizations also have defined efforts to build a system beyond the walls of a single division. For example, if an organization decides that one of its goals is to reduce electrical utility expenses, that organization s facilities management department would likely help drive the effort, rather than solely the IT department. Energy efficiency must be considered jointly by IT departments and facilities management departments to make it easier to clearly identify legitimate investment and avoid bias. To overcome organizational boundaries and ensure that effective actions are taken, it is critical to include the executive and to position energy improvement policy as part of organization-wide strategy. Use of PUE metrics The basic idea behind the use of PUE metrics is that the invisible cannot be improved. It is essential to introduce quantitative indicators to understand the degree of improvement that an organization has achieved in its energy efficiency efforts. Organizations should adopt good quantitative indicators, incorporating energy efficiency metrics such as PUE, understanding the effects of continuous measurement and analysis, and responding when conditions change.

5 PAGE 5 Solid improvement efforts As they approach energy efficiency improvements in the data center, organizations should explore the best economic situations while continuously implementing various measures to gain an understanding of true energy usage. The specific approach, of course, depends on an organization s particular situation, such as the maturity of the data center, but that approach commonly involves closely observing PUE, determining the causes of inefficiency, evaluating possible responses, and executing improvements. For example, to improve air flow, organizations can respond in a variety of ways, including addressing blank rack panels, installing a hot air exhaust return control board, and using aisle containment. Even more-mature data centers can find ways to improve their energy efficiency. When considering return on investment, organizations may find it possible to make cost-effective improvements, but it may be better to conduct a strategic migration or data center consolidation. (See The Green Grid white paper Assessment of EPA Mid Tier Data Center at Potomac Yard). Organizations also should take a long-term approach toward energy efficiency improvements as part of an organization s overall strategy. GRAND PRIX AWARD: HITACHI, LTD. IMPROVEMENT ACTIVITIES BASED ON VISUALIZATION OF OPERATION STATUS Hitachi, Ltd. was required to contribute sustainable social and environmental management for a client company. Data center operators were challenged to improve the total energy efficiency and IT optimization in the company s data center through the use of high-efficiency equipment in the facility. One area of particular concern had to do with hot spot management, which was an issue because of the company s increase in servers. Hitachi defined a strategic goal of reducing total data center energy consumption by 50% for five years starting in 2007, which is when the company began its data center energy efficiency project, named CoolCenter50, across the organization. Approach and solution For energy efficiency improvement, Hitachi took a three-pronged approach: Visualization, Assessment/Analysis, and Improvement/Optimization. The company found that, by conducting these approaches continuously, it was possible to achieve improvements in data center energy efficiency. Visualization. This approach involves collecting the multidimensional data that applies to a data center environment. The company found the following steps beneficial in its effort to gather comprehensive data:

6 PAGE 6 Hitachi monitored the temperature, humidity, and energy in the server room and installed power meters on all power distribution panels, including those in the server room. The company routinely patrolled for abnormalities in the server rack environment and facilities. Hitachi checked the power status of the building management system that collects measurements throughout the network, using anomaly detection to monitor environment status. Assessment/Analysis. This approach involves analyzing the root cause of energy inefficiencies. Hitachi found that it is important to evaluate and analyze the data periodically. It is effective to form a small work group of data center operators and conduct analyses based on the opinions of the operations team. Based on the results of visualization, the company periodically conducted evaluation/analysis meetings and examined collected data. It found that computational fluid dynamics (CFD) simulation also can be used for environmental analysis. As a result of its analysis, Hitachi found that an airflow shortage under the floor and an imbalance between hot and cold air were the likely causes of hot spots. Improvement/Optimization. This approach involves defining improvement goals and executing various actions based on problems found in the Assessment/Analysis phase. To improve the air flow shortage under the floor, Hitachi organized the cable under the floor, installed a partition plate under the floor, relocated the free access panel, and changed the fan placement for its grill panel. To improve the mixing of hot and cold air, Hitachi installed a blank panel, reviewed the grill position, and switched its air conditioner. Results As a result of air flow improvements, Hitachi achieved a 2 C temperature improvement at the top of the rack. The company decommissioned two air conditioners as a result of hot spot improvement. Overall, progress is on track for Hitachi to meet its five-year goal. The company continues to make various improvements, such as the replacement of old air conditioners for higher-efficiency units, the use of water spray at external cooling units, and so on. PERFORMANCE AWARD: FUJITSU LIMITED PROCESS IMPROVEMENT BASED ON CONTINUOUS VISUALIZATION OF ENERGY Awareness of all energy usage is important in achieving energy savings, and it is also important to quantify CO2 emissions and total energy costs after energy efficiency efforts have been made. Total energy usage, CO2

7 PAGE 7 emissions, and total energy costs are key data center metrics, and they help determine a company s environmental impact, level of corporate social responsibility (CSR), and profit model for data center outsourcing. In January 2008, Fujitsu Limited started its Energy Visualization Project, an effort that supports ongoing improvements in energy efficiency. Approach and Solution Fujitsu publishes a regular Energy & Environment Report to accelerate data center energy efficiency improvement based on: The conversion of non-electricity energy to CO2 emissions Splitting shared facilities proportionally (air conditioning power based on ratio of IT power and lighting power based on area ratio) and apportioning them appropriately to each customer Utilization of PUE as a measurement Because measurement points are different for different locations in each data center, Fujitsu does not compare the results of its data centers to each other. Rather, the company s goal is to improve the energy efficiency of each data center independently. Fujitsu undertook the following steps to publish its Energy & Environment report: Examine the current energy usage status at each data center Gather feedback from operations and management teams at each data center Define common information-gathering methods Define work flow and information flow from initial data gathering to the publishing of the report Develop a report macro to help automate worksheet updates Results In January 2009, Fujitsu published its initial Energy & Environment Report. The fact that the company could share real findings involved with the operation of centers and could recognize efficiency issues was a significant achievement. Some of the findings in the report include those associated with: Temporary increases in energy self-generation operation as a result of electric power outages by legal facility inspection Temporary increases in air conditioning energy before and after the installation of new equipment As part of its continuous improvement efforts, the company is planning to: Increase the breadth of content in its report Improve reporting speed Add report content based on Japan Data Center Council (JDCC) guidelines

8 PAGE 8 SPECIAL AWARD: IDC FRONTIER, INC. PUE IMPROVEMENT UTILIZING EXTERNAL AIR FOR LARGE-SCALE DATA CENTER IDC Frontier, Inc. built its Kita-Kyushu data center in To improve the data center s energy efficiency, the company adopted the external air utilization method and now uses the dry-side economizer method. IDC Frontier was able to cost-effectively implement these economizers, considering both the return on investment (ROI) and the cost impact on data center customers. When the company began to rely on large-scale external air utilization, there was no meaningful production data about the use of dry-side economizers under Japan-specific weather conditions, which include hot, humid summers and cold, dry winters. This lack of data and the scale of IDC Frontier s implementation made the project challenging. The Kita-Kyushu data center must have a high level of reliability because it is a hosting data center that also houses services. Because downtime was not an option, the company executed a largescale proof-of-concept study to establish production operations that could meet both economic and reliability requirements. Approach and Solution IDC Frontier evaluated the following two approaches: the isolation of cool and hot air for improved cooling efficiency and external air utilization using a dry-side economizer. Isolation of Cool and Hot Air for Improved Cooling Efficiency To improve cooling efficiency, IDC Frontier used a hot-aisle containment design to implement hot-air and coldair isolation. (The company also considered cold-aisle containment but selected hot-aisle containment because of cost and operational efficiency advantages.) The hot-aisle containment design may not be effective at lower power density levels, such as 6 kilovolt-ampere (kva) per rack, but it works efficiently at much higher power density levels, which will be required in the near future. To maximize cooling efficiency, IDC Frontier raised the floor height to 1 meter, which is higher than the floor height in typical Japanese data centers. The company did not position cables under the raised floor, which supports smooth air flow as validated by CFD simulation. To optimize cooling efficiency, IDC Frontier is continuously improving air flow; for instance, it installed blank rack panels, which the company provided free of charge to its customers. External Air Utilization Using Dry-Side Economizers IDC Frontier challenged itself to improve PUE by implementing the external air cooling method using dry-side economizers. To confirm the efficiency of this method, the company executed a large-scale proof-of-concept project, which included 100 racks with 6 kva power loads. The company used actual servers as well as alternative server emulation hardware to fill all 100 racks. Through its proof-of-concept project, IDC Frontier

9 PAGE 9 found that it could reach optimized energy efficiency levels utilizing external air as 10% of the total cooling air capacity. Overall cooling power consumption was reduced by 40%. To optimize external air usage from a cost standpoint, the company needed to develop operational expertise. IDC Frontier needed to balance intake fan power consumption and external air temperature, tuning the fan speed to achieve greater efficiency and to establish the most cost-effective operation. For example, when the external air temperature is low, fans initially take in a large amount of air, gradually reducing that intake amount by carefully controlling fan speeds. It should be noted that IDC Frontier considered the reuse of hot air exhaust from the hot aisle, but it is difficult to change hot air exhaust into energy. The company decided to direct its hot air exhaust directly to a greenhouse that was built just outside the data center and now successfully produces paprika, dragon fruit, and other fruits and spices. Results IDC Frontier measures PUE on a monthly basis and uses that measurement to internally monitor and evaluate energy efficiency. By utilizing external air for its proof-of-concept project, the company improved PUE. The company uses external air for about 10% of its total cooling air and has reduced overall power consumption by 40%. By monitoring PUE, IDC Frontier now has the ability to respond quickly to efficiency degradation situations, and it can develop immediate action plans to help execute its continuous improvement efforts. II. Facility Architecture Case Studies Container-type data center design has several merits, such as lower construction and operation costs and shorter construction periods, compared with existing data center specific building designs. Containerizing data centers is considered an effective solution for reducing total cost of ownership. Large-scale Internet portal data centers (IPDCs) are already using containerization in North America. Until recently, however, no major containerized data centers were installed in Japan due to several regulations, such as the Building Standard Law, fire laws, and traffic laws. Recently, these regulations were changed, and hosting data center players began to implement containerization in their data centers. To improve energy efficiency in any data center, it is critical to synchronize the operation of IT equipment and facility equipment management. It tends to be easier to manage that synchronization in containerized data centers because of their small size, and organizations can expect increased energy efficiency as a result.

10 PAGE 10 In the Internet Initiative Japan, Inc. case study below, the company adjusted its operation mode to meet Japanspecific seasonal variation. It is notable that the company took care to prepare three operation modes for its air/cooling system, thus maximizing energy usage efficiency. The Hitachi case study below highlights energy efficiency improvements for an existing data center facility and office building server room facility using a modular design concept that comes from the unit idea in containerized data center designs. Using an in-house modular structure makes it easier to improve efficiency through the right combination of spot/local cooling system management and IT workload management, which is similar to a container-type data center. The modular design also is flexible to modify and can be used to upgrade an existing facility, which enables a small initial investment and step-by-step expansion. Energy efficiency improvement is a long-term journey. Organizations need strategies that take them from the mid-term to the long-term, and they need consistent action to get optimized financial results. These case studies demonstrate that unit-based facility structures can support easy implementation of integrated IT workload and cooling equipment management to improve energy efficiency, as well as to improve facility flexibility. Additionally, when organizations use the newest high-efficiency cooling equipment technology, they can expect to improve PUE scalability. INTERNET INITIATIVE JAPAN, INC.: NEXT-GENERATION MODULAR DATA CENTER If data center service providers do not take steps to improve their environmental impact and the costs associated with that impact, it is difficult for them to survive. By reducing power consumption and improving PUE, services providers can create healthier businesses. Such is the case with Internet Initiative Japan, Inc. For the company to become more energy efficient, it needed to develop advanced cooling solutions to dramatically improve its existing cooling efficiency. After conducting its own research, Internet Initiative Japan reached the conclusion that the external air cooling method was the most appropriate for its particular circumstances. The company, which is a telecommunications provider, set a target of making a high power density more than 10 kva/rack available to any place within Japan, with the exception of Okinawa Island. Because air flow management becomes too complicated on the floor of traditional large-scale data centers through the external air cooling method, the company selected a containerized data center design to realize its goal.

11 PAGE 11 Approach and Solution The company s solution needed to meet local regulations and support Japan s unique climate. The containers that Internet Initiative Japan uses are specifically designed to meet Japanese regulations. For instance, their exhaust fans and fire extinguishers meet Japanese fire department law, and they meet safety guidelines under Japanese facility regulations. At first, the company evaluated the idea of importing containers that were compatible with International Organization for Standardization (ISO) standards, but, considering transfer and maintenance cost, it made the decision to create its own containers in Japan. To effectively support the Japanese climate with four distinct seasons, each with its own weather conditions the company designed three selectable operation modes (external air operation during spring and autumn, internal air conditioner mode for summer, and mixed mode for winter see Figure 1). The damper in the airhandling module is managed by inverter control, and sensors monitor temperature and humidity. Figure 1. The three modes reflect normal seasonal weather conditions in Japan Results By designing three operation modes, the data center can effectively react to both daily and seasonal environmental changes. During the proof-of-concept study for this project, Internet Initiative Japan recorded a partial PUE (ppue ) of 1.06 using the external air cooling method for its containerized data center. The company also validated operation at a higher temperature during the proof-of-concept study. When the temperature is too high, the server fan speed can increase too much and increase power consumption, so Internet Initiative Japan found that it was critical to maintain balanced operation. The company also found that it needed expertise in air operation management to effectively utilize external air, especially in the mixed operation mode. The company used a slanting rack placement design to support various IT equipment sizes. This design also helped the company reduced the container s width to meet typical Japanese sizes for transfer, which call for containers of less than 2.5 meters in width.

12 PAGE 12 Using the knowledge garnered from this proof-of-concept project, Internet Initiative Japan opened several more energy-efficient data center parks at Matsue City in Shimane Prefecture in April These data centers are ideal for use in a cloud environment. HITACHI: GREEN SOLUTIONS WITH A MODULAR DATA CENTER In Japan, generally speaking, the product life cycle for IT equipment is 3 to 5 years, but the life cycle for data center facilities is more than 10 years. Because of this difference in life cycle, data center facilities have not being able to accommodate the development of high-density IT equipment, and old air conditioning systems are causing energy waste. Land prices are high in Japan, so organizations seek out space-saving IT equipment and data center facilities, which is why many organizations consider modular data center designs. These designs tend to save electricity and space, and they lend themselves to flexibility and agility in responding to facility floor requirements. These designs also make it possible for organizations to start from a small scale and gradually expand. Approach and Solution Hitachi chose a unique modular data center design. The unit is 3.6 m 10 m 6.3 m in size and can support a rack with maximum electricity consumption of 25 kilowatts (kw). Hitachi designed the local cooling system with a power distribution board and air conditioner that are placed within the module, and the combination of server rack and rack-type air conditioner help achieve cooling efficiency. (See Figure 2.) This design prevents air stagnation and efficiently cools the entire module. As a result, servers can be placed densely, which reduces the number of racks required. Figure 2. Hitachi s cooling system design

13 PAGE 13 To achieve an efficient local cooling system, Hitachi introduced a natural coolant circulation method. The natural coolant circulation method uses the differences in facility height instead of energy to circulate the coolant, and it cools the server room by heat of vaporization with coolant. (See Figure 3.) This system also makes it possible to cool the coolant through the use of outside air. The system can use multiple controls for heat exchange and answers clients requests to not bring water into the data center. Figure 3. Hitachi s coolant circulation system design Results During its experimentation, Hitachi found that using this local cooling system cut electricity consumption by a maximum of 67% percent, compared with the power consumption of the same IT equipment plus air conditioner used in normal data centers 1. The company also reduced the data center floor area by a maximum of 80% percent. (See Figure 4.) 1 Compared with the power consumption of IT equipment plus air conditioner in normal data centers, assuming that their IT equipment is the same.

14 PAGE 14 Power of Cooling 67% Reduction Power of IT equipment Power of IT equipment Traditional This Modular Data Data Center Center Figure 4. This is Center a comparison between the power consumption in a traditional cooling system and that of natural coolant circulation using a containerized local cooling method 23 In Japan, where land prices are high, saving space can have a significant economic effect and can also help Hitachi achieve energy savings. Hitachi not only introduced this unique system in its own Yokohama data center, but it also could use the system to effectively improve existing data centers outside Japan (such as Telehouse and Green Data Systems in Europe) and when refurbishing server rooms in many existing tenant buildings. III. Electricity and Cooling Case Studies When it comes to data centers, organization have many options in terms of how they handle electricity and cooling. The NTT Facilities, Inc. case study below shows an AC/DC power conversion loss-reduction approach using high-voltage direct current (HVDC) power distribution. In this case, grid power is provided by AC within the data center, DC power is provided within IT equipment, and power distribution includes an uninterruptable power supply (UPS) system, which includes AC/DC conversion points. NTT Facilities improved its power distribution efficiency by minimizing conversion loss in power distribution. It should be noted that an efficiency comparison must be made between AC power distribution and DC power distribution. The NTT Facilities case study demonstrates improvements in a particular data center specific 2 The ratio of IT equipment power and air conditioner power is taken from Japan Electronics and Information Technology Industries Association (JEITA) announce document (June 2009). 3 Calculated as coolant natural circulation system + chiller + cooling tower.

15 PAGE 15 situation. The Green Grid has conducted power distribution analysis and has produced several white papers on this topic, including Quantitative Analysis of Power Distribution Configurations for Data Centers and Issues Relating to the Adoption of Higher Voltage Direct Current Power in the Data Center. Using an HVDC solution is one effective method to consider when looking to simplify an organization s power distribution structure. Traditional telecommunications data centers have been using 48 volt (V) DC power distribution, but by using HVDC, they can improve cable space utilization and flexibility. NTT Facilities has taken great care to address safety concerns having to do with HVDC, and the company has done considerable work regarding the standardization of HVDC safety for everyone s benefit. The second and third case studies in this section AT Tokyo (@Tokyo) and ITOCHU Techno-Solutions Corporation discuss power consumption leveling, another approach to data center power consumption management that takes advantage of the difference in cooling loads during the day and at nighttime. If an organization can store energy at night and use that stored energy during the day, it can better manage its grid power usage levels. This peak shift can reduce the grid power load, and, if a data center can get a lower price for its nighttime grid power supply, it can also reduce its total cost of ownership. Following the March 2011 earthquakes in Japan, the country has faced a continuing shortage in its grid power supply. These case studies show a peak shift method that is particularly effective, especially considering such grid power supply constraints. NTT FACILITIES, INC.: PRODUCTION PROOF-OF-CONCEPT STUDY OF THE HVDC POWER- DISTRIBUTION METHOD The data center industry has become interested in DC power distribution which has been used in telecommunications systems from a reliability and efficiency standpoint. But there are concerns about traditional 48 V DC power distribution in terms of the thickness of the power cable, which can have a negative impact on operation and cable space. To resolve this issue, NTT Facilities realized that it was necessary to develop a HVDC power distribution method. Since this is new development project, the company needed to ensure that its design was secure enough to safely manage HVDC; at the same time, it needed to ensure standardization, which was an added challenge. Approach and Solution NTT Facilities needed its design to support the increasingly higher power density of IT equipment, which often causes issues because of thicker cabling and space constraints. The company decided to upgrade its voltage to 380 V and reduce the amount of current, which enables the use of thinner power cables. This solution also

16 PAGE 16 reduces cabling costs, and it can improve cooling efficiency by reducing the problems caused by raised floor power cable distribution. HVDC distribution systems use a higher level of voltage compared with traditional AC power distribution, which means that it was critical to design equipment that is safe for human operation. To protect against electric shock, NTT Facilities designed a new HVDC support power plug and receptacle, with features such as a newly designed ground line that minimizes impact to the human body. (See Figure 5.) In this design, power-connecter parts are all covered so that people cannot inadvertently touch them, and the design, which has an integrated mechanical off switch, protects people from the arc that is caused when pulling off the plug. Safety Lock, to be standardized by IEC about location of lock position Figure 5. NTT took safety into account when designing its HVDC system Results NTT Facilities executed this production proof-of-concept effort from January 29, 2009 to October 30, During the project, actual total power consumption (including IT equipment, power distribution, and cooling equipment) was reduced by 18%, compared with current the company s regular AC power distribution. (See Figure 6.) This reduction translates into a cost reduction of 410,000 JPY (U.S. $5,326) per year for this data center.

17 Energy consumed [kw] r Reduction result [kw] r PAGE kW 0.24kW kW kW kW 9.59kW 7.94kW 10.33kW 10.09kW kW 3.34kW 0.78kW System overall Power system loss A/C system ICT equipment (A) (B) (C) HVDC system UPS system Reduction result Figure 6. Reductions in total power consumption using the new HVDC design Because of the successful proof-of-concept project, other parts of NTT Facilities have become interested in pursuing HVDC for increased energy efficiency. NTT s laboratory has already decided to implement HVDC for production use, and NTT Group started production implementation of HVDC in AT TOKYO (@TOKYO): AIR CONDITIONER EFFICIENCY WITH A THERMAL STORAGE SYSTEM Japan has limited energy resources of its own it can only supply 4% of the nation s total energy requirements 4. However, the country has created a well-balanced power generation environment, maximizing the respective advantages of different types of power generation methods, including nuclear power, thermal power, and hydropower. This balance takes into consideration such aspects as supply stability, environmental impact, and economic efficiency. Over the course of a single day, power demand fluctuates significantly between nighttime off-peak and daytime peak. During the summer, demand may fluctuate as much as 50%. Therefore, flattening the power demand curve and using nuclear power generation which releases no greenhouse gases can be an environmentally friendly choice. 4

18 PAGE 18 AT Tokyo wants to encourage the generation of alternative energy, such as hydroelectric and thermal power, to flatten the demand curve. Hydroelectric power is the power to pump water from a lower to an upper reservoir to create water reserves that are discharged during the daytime to drive the turbines that generate power. With thermal power, at-home heat pumps heat water as demand arises. The company is providing financial support for energy-saving systems such as these, with the goal of reducing environmental impact and total energy costs. Approach and Solution System configuration Heat source equipment: centrifugal chiller (turbo refrigerator) Thermal storage tank: 5,000 m3 class Total 1,400RT / 700RT 2,100RT Cooling Tower Turbo Chiller AHU chilled water Thermal Storage Tank Figure 7. The thermal power design suggested by AT Tokyo (@Tokyo) The design calls for the thermal storage system to run a centrifugal chiller using electricity generated during nighttime and to store cold water for 5,000 m3 class thermal storage. (See Figure 7.) Thermal energy will be applied to daytime air conditioning so as to reduce the amount of CO2 emissions that run down the centrifugal chiller during daytime.

19 PAGE 19 Freezing machines, which provide cooling water for the data center air conditioner, should run during nighttime rather than daytime to improve effectiveness based on coefficient of performance (COP). Furthermore, freezing machines can be run with rated operation. Additionally, the operation rate will rise because daytime running power can be covered by a thermal storage tank.. Results The AT Tokyo (@Tokyo) established the following findings (see Figure 8) when comparing its thermal system design with an unused thermal storage system, keeping in mind combustion gas from the electric generation plant: Energy-saving effect of shifting nighttime energy: Environmental effect of load reduction: 11,290 kilowatt-hour (kwh) SOx:39.4%(approximately 3 kg/day) Heat Storage Operation Heat Radiation from storage Cooling Operation 0:00 8:00 22:00 0:00 Figure 8. A thermal power system can be more energy efficient by taking advantage of normal temperature changes ITOCHU TECHNO-SOLUTIONS CORPORATION: POWER LOAD EQUALIZATION WITH SODIUM-SULFUR BATTERY SYSTEM Most data centers were built more than 10 years ago and were designed without taking green considerations into account. When improving the energy efficiency of commercial data centers, organizations need to figure out how to alter or replace the facility without stopping the systems. Additionally, these improvements require a significant investment, so organizations must ensure that improvements will result in reductions in operating costs to offset that investment.

20 PAGE 20 ITOCHU Techno-Solutions has a data center that was established in 1988, and the company began to make energy efficiency improvements to it a few years ago. Some of those improvements included the visualization of energy efficiency in reference to PUE, a step-by-step transition to energy-efficient equipment, a change to the server room layout by separating hot and cold aisles, and alterations aimed at cost reduction. Approach and Solution As previously discussed, the amount of air conditioning equipment used in Japanese data centers varies widely in terms of electricity usage during the day versus at night. ITOCHU Techno-Solutions wanted to make improvements to equalize the burden, which would conserve energy and provide economic savings. To do so, ITOCHU Techno-Solutions opted to use sodium-sulfur batteries, which use beta alumina ceramics for the electrolyte layer. These batteries use sulfur (S) in the cylinder that serves as the positive electrode, and they use liquid sodium (Na) that serves as the negative electrode. A sodium-sulfur battery can discharge and charge at around 300 C and is said to be one of the most efficient, energy-intensive, and long-life battery systems. Figure 9. Use of sodium-sulfur batteries can help equalize energy use at the ITOCHU Techno-Solutions data center (Source: Tokyo Electric Power) Moreover, ice thermal storage air conditioning systems are also highly efficient and offer excellent energy savings. By combining ice thermal storage and sodium-sulfur batteries, ITOCHU Techno-Solutions can store electricity during the night, when energy tariffs are less expensive, and power can be discharged during peak daytime hours to equalize power use and reduce electricity costs. (See Figure 9.) System configuration: Sodium-sulfur battery system 750 kw Ice thermal storage air conditioning system 125 RT

21 PAGE 21 heat storage tanks x 4 49,216.8 million joules (MJ) Results ITOCHU Techno-Solutions found that it could reduce peak power usage by 6.3% because of the shift toward storing nighttime energy. (See Table 1.) Electric Power Shift Generating Power (A) 400 kw Output Time (B) 11 hours Electric Power Shift (C)=(A) (B)= 4,400 kwh Heat Storage (D) 24,608.4 MJ COP (E) 2.43 Electric Power Shift (F)=(D) (E) 3.6MJ/kWh= 2,813 kwh Total Electric Power Shift (G)=(C)+(F)= 7,213 kwh Percentage Consumption Power by Day (H) 113,534 kwh Percentage of Night Shifting (I) =(G) (H) = 6.30% Table 1. The difference in electricity consumption when storing nighttime power for use during the day As mentioned above, by combining a sodium-sulfur battery and an ice thermal storage air conditioning system, ITOCHU Techno-Solutions can use inexpensive nighttime electricity and produce cool thermal energy by using cool air at night. The company therefore equalizes its power usage, which leads to a reduction in electricity costs. Additionally, the use of nighttime electricity, which is less carbon-intensive than daytime electricity, could also lead to the reduction in greenhouse gas emissions. The design that ITOCHU Techno-Solutions is using could be effective as an emergency generator as well. Because the facility does not involve any combustion and toxin emissions are not a concern, it has a cleaner environment than many other in-house emergency generators.

22 PAGE 22 IV. Data Center Operation Case Study The last energy efficiency case study highlights the way that an organization handles the daily operations of its data center. If an organization can allocate appropriate IT resources according to need and can match the operational status of IT equipment to the needs of the facility, it can reduce energy usage. However, automated operations can be an issue for data centers because it is difficult to maintain increasingly complex IT infrastructures. Proper operations can result in real-time power savings, and organization can improve PUE by preventing human error when it comes to effective operations. In the case study below, NEC controlled surplus equipment by powering off IT equipment and automating air control based on the load using power-saving software. Although NEC is using newer technology, the future standardization of the API and accumulation of a knowledge base will help organizations adopt similar practices. NEC: USE OF ENERGY MANAGEMENT SYSTEM In recent years, data center operators have been required to manage greenhouse gas emissions based on various regulations, and many have set targets for emissions reduction. They also have been required to define solutions to improve PUE. While organizations work to reduce emissions and improve PUE, they run the risk of making their air conditioning unbalanced due to the IT equipment load change. Some organizations have experienced problems with exhaust wrap and hot spots. Approach and Solution To solve these problems, NEC found that it is effective to monitor IT equipment in the server room and control the operation mode of that equipment. Specifically, the company uses power control software to monitor the operation of IT equipment to increase overall energy efficiency. The IT equipment uses self-reliant power control and load control. The three main control functions manage power consumption, redundant server power-off, and elimination of hot spots. Power consumption control NEC implemented two methods to control total power consumption of the entire system. (See Figure 10.) One method protects the maximum amount of power control, and the other controls power to the virtual servers through power management. Together, these functions autonomously control power usage.

23 PAGE 23 Figure 10. The two means of controlling power consumption used by NEC (Source: Tokyo Electric Power) Redundant server power-off control When a system has multiple servers, it also has multiple levels of server loads, which can prevent the effective use of server resources. By shifting server loads to a specific physical server, that server will be able to maintain the proper load level, and the redundant servers can be turned off. (See Figure 11.) NEC can do this during periods of low load operation at night and early morning.

24 PAGE 24 Figure 11. NEC can avoid wasting power by concentrating its workload on a single server during off-peak hours (Source: Tokyo Electric Power) Hot spot elimination By installing sensors in various places, such as on servers and racks, NEC can measure temperature, humidity, and power state, and it can detect hot spots or heat regions. (See Figure 12.) The company can optimize overall energy usage in the server room by reallocating any jobs that create heat to low-workload servers and automatically adjusting air flow and direction. monitor humidity, temperature, electricity detect hot spot Relocate server for heat equalization temperature High Low Monitoring air-conditioning controls Handle hot spots by controlling air conditioning Figure 12. NEC optimizes energy usage through the elimination of hot spots in its data center (Source: Tokyo Electric Power)

25 PAGE 25 Results NEC achieved a power savings of 30% by using power control software to better control the server room. If the company had tried to handle that level of management manually, it may have experienced a prolonged analysis time as well as errors, depending on the skill of the administrator. By using power control software, the company sped up its control process and removed the risk of human error. V. Conclusion Organizations can use the case studies provided in this white paper to make sound decisions about how to undertake energy efficiency improvements in their own data centers. Organizations can gain insight about some of the positive and often innovative steps that the highlighted companies have taken and can determine how best to balance risk and potential improvements with regard to total cost of ownership, reduced environmental impact, and greater overall efficiency. VI. Acknowledgements The Green Grid would like to thank the companies that participated in the energy efficiency efforts that are featured in this white paper: AT TOKYO Corporation Fujitsu Ltd. Hitachi Ltd. Internet Initiative Japan, Inc. IDC Frontier, Inc. ITOCHU Techno-Solutions Corporation NEC Corporation NTT Facilities, Inc. VII. About The Green Grid The Green Grid is a non-profit, open industry consortium of end users, policy makers, technology providers, facility architects, and utility companies collaborating to improve the resource efficiency of data centers and business computing ecosystems. With more than 170 member companies around the world, The Green Grid seeks to unite global industry efforts, create a common set of metrics, and develop technical resources and educational tools to further its goals. Additional information is available at