When it came time for Emerson Network Power to consolidate dozens of its mostly collocated data centers scattered around the globe into a new data center at their campus just north of St. Louis, the most interesting feature wasn’t even put inside the building.
As part of this consolidation Emerson, who manufactures 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 you can make a new data center.
When Emerson built the new data center, they wanted it placed on a particular spot on their campus that didn’t line up with the best orientation for the array. This resulted in an extra expense to tilt the array on a slight angle to get the maximum exposure to sunlight. Currently, it 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 — that 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 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 in such a way as to minimize light pollution to the surrounding area. Interior lights also turn off automatically when a room is not in use, and large windows that are hurricane-proof are used liberally to bring in daylight to the offices and further reduce power consumption.
The data center has a twin (without the array) in Marshalltown, Iowa that is used for disaster recovery and R&D purposes. It is also the first commercial deployment of Liebert’s NXL power conditioning system (see link). There are other Emerson technologies installed throughout the building, both for practical purposes as well as to showcase the products for visitors.
Typical of many a newer data center is to use rack-specific cooling towers so as not to have air condition the entire air volume of space inside the server area. This means that 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.
They also alternate 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 is only running less than ten 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 said.
Another innovative feature is that fiber optics rather than copper will handle all rack-to-rack wired connections. This boosts bandwidth and cuts down on the power that is needed to move all the data around between racks, since fiber doesn’t have as much electrical resistance as copper wiring.
Emerson is powering their 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. Notice that there aren’t any IBM mainframes on the floor – Emerson made a conscious decision to move away from them in their new data centers, and they are in the process of migrating their 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, and combined with high telecom bandwidth (most of the cross-country Internet lines are nearby) and a moderate climate means that power needs are also reasonable. They also make use of lower-powered CPUs and like many modern data centers have extensive use of virtualization technologies to consolidate servers.
The array has been operating within its predicted parameters and they haven’t had any problems with it in the past year, according to the company. All told, Emerson claims 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.