The 'Lights Out' Data Center

Data centers are known for being cold and loud. Add "dark" to the list, if you haven't already.

The Planet said today that it expects to reduce its annual energy consumption by 1.4 million kilowatt hours, gaining nearly $140,000 in savings, through "more efficient use of lighting." Translation: they're strictly enforcing a policy for turning out the lights after hours. That means The Planet's six data centers will be lit only from 8 a.m. to 5 p.m., with smaller lamps remaining on in main areas for safety and navigation. "Data-center technicians who work around the clock now turn on lights as needed in computer rooms," the company said.  

The Planet's lights-off policy extends to all data center facilities, including the electrical and mechanical rooms, as well as the company’s corporate offices. Primary lighting and HVAC are programmed to run from 7 a.m. to 7 p.m. Only the areas staffed 24/7, including the Call Center, Network Operations Center and Sales, have the option for after-hours zone lighting and HVAC.

This seems like a simple and obvious step, but practices differ. Some data centers keep the raised-floor area brightly lit. Others use minimal lighting, creating an environment in which the green and blue server lights provide the primary illumination. Still others use purple or blue lighting, which may or may not have environmental benefits, but definitely gives the data center that wicked cool "alien spaceship" look.

"While lighting is a small portion of the total power usage of a datacenter, it can be often be safely reduced through mature, inexpensive technologies and designs," according to data center energy management best practices from Lawrence Berkeley National Laboratory, which recommends using motion sensors to turn lights off in empty rooms.

LBL says motion sensors can also be used in combination with bi-level lighting, which uses low light as its default and switches to a higher level of illumination when motion is detected. Bi-level lighting is typically used in pathways and stairwells.

Lighting management is a key component of projects seeking certification under the LEED (Leadership in Energy and Environmental Design) standard from the U.S. Green Buildings Council, the national benchmark for the design and construction of high performance green buildings. Occupancy sensors and schedule-based lighting schemes can gain points towards a LEED certification.

Many central lighting control systems are now web-enabled, allowing offsite monitoring via a web browser. The Square D unit of Schneider Electric, for example, provides systems that monitor run-time for lighting systems and can send an e-mail to a computer, cell phone or pager when a usage parameter is exceeded.

AISO.net, one of the few data centers powered by solar energy, extends its green philosophy into its interior lighting. AISO uses solar tubes, which collect sunlight from domed rooftop skylights and direct it through tubes lined with reflective material, which connect to interior lights. AISO also saves on its power bill through the use of LED (light-emitting diode) lighting products.

The EPA's National Computer Center in Research Triangle Park, North Carolina generates some of its power using a rooftop solar array, but also uses solar-power lighting in parking lights and exterior pathways.

Does this type of granular approach to lighting management matter in facilities that use 10 to 50 megawatts of power? It does for The Planet, which has six data centers as well as office space in both Dallas and Houston. The $140,000 savings from lighting can go toward powering the 56,000 servers in those data centers. 

We should note that while The Planet has dubbed its initiative a "lights out" program, that steps another usage of the term in the industry in which a facility that is operated remotely via automation, with no staff present, is known as a "lights out data center."