- Total data center energy usage growth is slowing down in the U.S.
- Data centers are reducing energy demand through improved airflow and thermal management.
- There are still plenty of opportunities to save energy in vintage data centers.
The growth in data center energy use is slowing down, even though the number of data centers continues to rise, according to a recent U.S. Department of Energy report. From 2000 to 2005, U.S. data center use grew by 90 percent. Between 2010 and 2014, however, data center energy use increased by just 4 percent. The report identifies a number of reasons for this:
- Reduced growth in the number of servers operating in data centers
- The power demand per server has remained fairly constant since 2005
- Improvements in the power scaling capabilities of servers, reducing power draw during idle periods
- Increased efficiency of storage devices on a per-drive basis
The recent trend away from smaller data centers toward fewer, but more efficient, hyperscale facilities is another contributing factor. The DOE expects little growth in energy usage for the remainder of the decade.
Data center power usage effectiveness adds another twist to the story. This metric represents the total energy used by the data center facility in relation to the energy needed for the IT equipment. Data centers have reduced their total energy demand through improved airflow and thermal management measures—such as hot aisle/cold aisle arrangements and set point temperature adjustments. The DOE estimates current and future PUE values for data centers as shown in the following table.
|PUE Values for Selected Data Center Sizes|
|Space Type||Size (ft2)||2014||2020|
|Room||100 to 500||2.5||2.35|
|Midtier||2K to 20K||1.9||1.79|
By comparison, Google now claims an average of 1.12 PUE for its newest data centers.
Teaching old data centers new tricks
Despite these trends, Philip Fischer (Global Data Center Segment Manager, Eaton) has identified issues with older or vintage data centers that illustrates the remaining untapped potential for energy reduction:
- Aging equipment. Components often nearing the end of their recommended service life.
- Low efficiency power and cooling equipment. Not fully loaded. According to the NRDC, “the average server operates at no more than 12 to 18 percent of its capacity while still drawing 30 to 60 percent of maximum power."
- Insufficient cooling capacity or ineffective cooling. They often struggle to cope with the intense heat generated by today’s dense, power-hungry IT equipment.
- Crisis response and disaster recovery (DR). Updated crisis response plans. Develop a new one if none exists.
- Speed to deploy. Some data centers have a requirement for avoiding hot electrical or mechanical work during peak operating time, but often the site may not have the same level of discipline or structure with respect to the wiring.
- Security. In many vintage data centers, the infrastructure was not developed to account for today’s strictest data security and increased privacy needs.
- Inappropriate sizing. The existing equipment may be over-provisioned or under capacity.
- Lack of flexibility and scalability. Vendors, data centers, and utilities will need to work together to find viable solutions for supporting increasingly dense IT environments and fluctuating data processing conditions more sustainably.
So, while the overall trend is toward decreasing energy consumption, there are still plenty of opportunities to save energy and money.
Image source: iStock