IT Expert Voice

When Emerson Network Power consolidated dozens of data centers around the globe into a facility at its campus just north of St. Louis, the most interesting feature wasn’t even inside the building.

As part of its consolidation, Emerson, which makes a wide array of power conditioning and management systems, built a new 35,000 sq. ft. data center in St. Louis last year. The building sports a rooftop 100 kV (DC) solar array that occupies about a quarter of its surface area. The array provides about 15% of the power requirements for the equipment inside and is just one of several technologies that are used to show how green a new data center can be.

Emerson's new data center has a large photovoltaic solar array on its roof.

The new data center is in a particular spot on Emerson’s campus that doesn’t line up with the best orientation for the array.  This required an extra expense to tilt the array on a slight angle for the maximum exposure to sunlight. Emerson’s installation is the largest collection of solar panels in Missouri on a commercial building.

The array is just one of several green building technologies used to qualify the data center for Leadership in Energy and Environmental Design (LEED) Gold certification. (To put this in perspective, a new data center built last month for StreamDataCenters.com in San Antonio only received silver LEED certification.) Emerson also put the air conditioning condensers on the roof, which reduced the overall building footprint by more than 15,000 sq. ft. and eliminated more than two miles of copper tubing needed to carry the coolant. The saved space on the ground was used for plantings and grass.

The roof is white to save about $800 per year in cooling costs, and all exterior lighting was shielded to minimize light pollution to the surrounding area. Interior lights turn off automatically when a room is not in use, and large hurricane-proof windows are used liberally to bring daylight into the offices and further reduce power consumption.

The data center has a twin (without the array) in Marshalltown, Iowa, used for disaster recovery and R&D. It is also the first commercial deployment of Liebert’s NXL power conditioning system (pictured below). There are other Emerson technologies installed throughout the building, both for practical purposes as well as to showcase the products for visitors.

Caption: Emerson’s Liebert NXL power conditioning equipment is just one of many Emerson technologies used in their data center.

Emerson's Liebert NXL power conditioning equipment is just one of many Emerson technologies used in their data center.

Typical of many a newer data center is the use of rack-specific cooling towers to eliminate the need to air-condition the entire air volume of space inside the server area. Only the air space immediately inside each rack is cooled, which results in big power savings. Emerson used the XD equipment from its Liebert division to pull cold air directly to the racks.

The Liebert XD rack-specific cooling equipment moves a minimum amount of conditioned air through the individual server racks.

The data center also alternates hot and cold aisles for more efficient air handling. The ambient room temperature is kept at a comfortable 76 degrees, again to reduce power consumption. The raised floor has a capacity for 5,000 servers but it is running less than 10 percent of that capacity at the moment, according to Keith Gislason, who oversaw the IT infrastructure project for Emerson and since has moved on to join the Avocent product management division of the company.

“We have had zero downtime during the past year. And while we have had some failures – including a lightning strike that caused one of our power buses to fail – otherwise we have been operating continuously,” he says.

Another innovative feature is that fiber optics, rather than copper, handle all rack-to-rack wired connections. This boosts bandwidth and cuts down on the power needed to move all the data between racks, since fiber doesn’t have as much electrical resistance as does copper wiring.

Emerson is powering its Dell Windows and Sun Solaris servers at 240 volts directly from the power distribution equipment. “All the high efficiency power supplies already supported that voltage, so we didn’t have to special order any gear,” says Gislason. In older data centers, power is provided at 480 volts and then stepped down to 120 volts to operate the equipment. Dell estimates that Emerson’s configuration will save around 20 MWhr of electricity annually.

There aren’t any mainframes on the floor. Emerson made a conscious decision to move away from them in their new data centers. The company is in the process of migrating its enterprise resource planning applications – their last critical IT infrastructure – onto more distributed systems hardware.

Locating a data center in Missouri makes a lot of sense … and cents too. The area has one of the lower power rates in the country. Combined with high telecom bandwidth (most of the cross-country Internet lines are nearby) and a moderate climate, power needs are also reasonable.

Emerson also makes use of lower-powered CPUs and, like many modern data centers, extensive use of virtualization technologies to consolidate servers.

The array has been operating within its predicted parameters. There haven’t been any problems in the past year, according to the company. Emerson says that the data center is at least 31% more efficient than traditional data centers that they were moving out of. So going green can end up saving a lot of green, too.

Related Information From Dell.com: The Smarter Path to Tackling Power and Cooling Issues