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About the Project
The design-build project provides a mission critical facility for the Social Security Administration (SSA), comprised of a Data Center, Office Building, Facility Access Center, Warehouse, Service Yard, and Energy Center. The NSC is the first LEED Gold data center for the General Services Administration. The facility complies with Mission Critical Criteria from the Uptime Institute Tier 3 design certification standards and contains the infrastructure necessary to support an IT load of 6 Megawatt (MW), expandable to 10 MW.
The NSC is the first LEED Gold Certified data center constructed for the General Services Administration. A large data center by nature consumes a significant amount of energy through the operation of the IT equipment. This presented an opportunity for the design team to reduce the energy usage required for the facility. Significant savings were realized with the use of water-cooled chillers and heat recovery wheels to operate the chillers with little to no load in the data center White Space, while using heat recovery chillers for latent cooling and hot water production. The use of an elevated chilled water supply temperature for sensible cooling allowed the waterside economizer to be used at over 70% of the yearly hours. This central plant design, along with custom computer room air handlers (CRAH) and the associated chilled water distribution system, helped achieve 40% LEED energy savings and 52% EPACT energy savings.
Additional efficiency measures include a 1 MW fixed tilt photovoltaic (PV) ground-mounted array. The solar PV system is a 1 MW Direct Current (DC) net metering operation utilizing a bi-directional utility meter, allowing the customer to quantify the amount of power produced versus the power that is imported. The total system is comprised of 75 sub-arrays, each consisting of 56 250-watt rack-mounted modules (manufactured by REC) spread out over approximately four acres of the project site. The sub-arrays are configured into four rows of 14 modules, each facing due south with a fixed tilt angle of 25 degrees on a moderate grade incline of six to 10 percent, which is supported with driven steel piles. Each sub-array is then combined to a single Satcon 1 MW utility-grade inverter with factory integrated/tested step-up transformer, disconnects and power conversion electronics. A solar thermal system produces 30% of the domestic hot water demand for the facility.
