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1. Processor efficiency
A typical thermal design power (TDP) processor in use today is between 80 and 103 watts (91 W average). For a price premium, processor manufacturers provide lower voltage versions of their processors that consume on average 30 watts less than standard processors. In a 5,000-square-foot data center modeled for testing, these versions create a 10 percent reduction in overall data center power consumption.

2. Power supplies
As with processors, many of the server power supplies in use today are operating at efficiencies below what is currently available. Best-in-class power supplies are available today that deliver efficiency of 90 percent. Use of these power supplies reduces power draw within the data center by 124 kW or 11 percent of the 1127 kW total.

3. Power management software
Data centers are sized for peak conditions that may rarely exist. In a typical business data center, daily demand progressively increases from about 5 am to 11 am and then begins to drop again at 5 pm. The inbuilt power management features are disabled because of concerns regarding response time; however, this decision may need to be reevaluated in light of the significant savings this technology can enable. Assume that the idle power draw is 80 percent of the peak power draw without power management, and reduces to 45 percent on enabling it. With this scenario, power management can save an additional 86 kW or eight percent of the unoptimized data center load.

4. Blade servers
Blade servers consume about 10 percent less power than equivalent rack mount servers because multiple servers share common power supplies, cooling fans and other components. More importantly, blades facilitate the move to a high-density data center architecture, which can significantly reduce energy consumption (by around 20%).

5. Server virtualization
Implementing virtualization provides an incremental eight percent reduction in total data center power draw for the 5,000-squarefoot-facility model.

6. Cooling best practices
Best practices, such as the hot-aisle/cold-aisle rack arrangement; sealing gaps in floors, using blanking panels in open spaces in racks, and avoiding mixing of hot and cold air, helps in cutting down power consumption. Computational fluid dynamics (CFD) can be used to identify inefficiencies and optimize data center airflow. Additionally, one could enable temperatures in the cold aisle to be raised if current temperatures are below 68° F, and also raise chilled water temperatures from 45° F to 50° F. These practices alone reduce overall facility energy costs by one percent with virtually no investment in new technology.

7. 415V AC power distribution
In most data centers, the UPS provides power at 480V, which is then stepped down via a transformer, with accompanying losses, to 208V in the power distribution system. Converting UPS output power to 415V could eliminate these step-down losses. In the model, an incremental two percent reduction in facility energy use is achieved by using 415V AC power distribution.

8. Variable capacity cooling
Newer technologies, such as digital scroll compressors and variable frequency drive in computer room air conditioners (CRACs), allow high efficiencies to be maintained at partial loads. In the chilled water-based air conditioning system used in this analysis, the use of variable frequency drives provides an incremental saving of four percent in data center power consumption.

9. High density supplemental cooling
Optimization by moving from traditional data center densities (2 to 3 kW per rack) to an environment that can support much higher densities (in excess of 30 kW), requires implementing an approach to cooling that shifts some of the cooling load from traditional CRAC units to supplemental cooling units. Supplemental cooling units are mounted above or alongside equipment racks, and pull hot air directly from the hot aisle and deliver cold air to the cold aisle. Supplemental cooling units can reduce cooling costs by 30 percent compared to traditional approaches to cooling.

10. Monitoring and optimization
Rack densities are rarely uniform across a facility and this can create cooling inefficiencies if monitoring and optimization are not implemented. Cooling control systems can monitor conditions across the data center and coordinate the activities of multiple units to prevent conflicts and increase teamwork.