Data centers waste a substantial amount of energy. That’s because they are designed for capacity, performance and reliability, usually at the expense of efficiency. Such waste unnecessarily increases capital and operational expenditures, and can result in finite resources (particularly power and space) being exhausted, thereby creating a situation where the organization might outgrow its data center. 

With the cost of electricity now representing 25 percent to 40 percent of all operational expenditures in data centers, organizations are starting to pay serious attention to energy efficiency. Indeed, the cost to power a typical server over its useful life can now exceed the original capital expenditure, according to both the U.S. Department of Energy and Gartner. Gartner also notes that it can cost over $50,000 annually to power a single rack of servers. And it is not just the servers consuming power: Every kilowatt-hour of electrical energy consumed by IT equipment produces heat that must then be removed by the power-hungry cooling system. 

Fortunately, there are numerous ways IT and facility managers can improve data center efficiency -- sometimes dramatically -- without adversely impacting capacity, performance or reliability. Here are ten steps IT and facility managers can take to improve efficiency without compromising reliability.

1.     Reduce Cooling Power Consumption

In a typical data center, only about half of the power available is actually used by the IT equipment, with the rest going mostly to cooling. Much of that power can be reclaimed by eliminating cooling inefficiencies, upgrading the cooling system to allow for variable cooling and/or making greater use of outside air. 

2.     Consolidate and Virtualize

Poor server utilization is one of the biggest sources of waste in most data centers. Virtualizing the servers can increase overall utilization from around 10 percent (typical of dedicated servers) to between 20 percent and 30 percent, and sometimes over 50 percent, with more dynamic management systems. This also reclaims a considerable amount of rack space and stranded power in the process. 

3.     Calibrate and Monitor Cold Aisle Temperatures

A best practice today is to adopt a hot/cold aisle configuration and increase the cold aisle inlet temperatures to 80.6°F. However, this can create hot spots that waste power and cause outages, so it is necessary to balance the equipment, and then calibrate and monitor the cold aisle temperature to maximize cooling efficiency and minimize problems. 

4.     Match Server Capacity to Load in Real Time

Even the best virtualized and recently refreshed server configurations waste power during periods of low application demand. Total server power consumption can be reduced by up to 50 percent by matching on-line capacity to actual load in real time. 

5.     Correlate IT/Facility Emergency Procedures

The lack of complete correlation between facility and IT emergency procedures can unnecessarily cause and/or extend application outages. 

6.     Determine Actual Power Consumption

Older equipment often uses power inefficiently, and newer servers can overload circuits more frequently when incorrectly allocated and aggregated. Using the PAR4 methodology in the Underwriters Laboratories UL2640 standard can maximize server capacity while eliminating the risk of overloading circuits. 

7    Eliminate the Transfer Switch

While the use of an automatic transfer switch between the grid and the generator is a common configuration, an AC (alternating current) or DC (direct current) distribution bus is far more efficient and just as effective during a power outage. 

8.     Load-Balance by Following the Moon

Many organizations operate redundant data centers to satisfy business continuity needs, but very few take full advantage of this powerful configuration. Having multiple, strategically located data centers enables application workloads to be shifted to where power is currently more stable and less expensive. Because power is invariably most abundant and least expensive at night, such a 'follow the moon' strategy can result in considerable savings. 

9.     Foster IT/Facility Management Consistency

Maximizing data center efficiency will require an unprecedented level of cooperation between IT and facility managers. 

10.   Monetize the Data Center

Electricity is expensive, and data centers will continue to consume an ever-increasing amount of it. The AC or DC distribution bus configuration better prepares the organization to reap financial rewards by participating in the smart grid’s ancillary energy markets and demand response events, or through distributed generation via net metering with a microgrid powered by sources of renewable energy. 


Some of these steps are surprisingly easy to take, and even the more difficult ones can normally be justified based on the substantial cost savings available. Simply put: Energy efficiency is the 'green' thing to do in data centers today -- for both environmental and financial reasons. 


Clemens Pfeiffer is the CTO of Power Assure and a 25-year veteran of the software industry.