VELCO’s 738 miles of transmission lines span the rural state, delivering reliable power to its 17 distribution utility owners.

New Data Center Powers a Sustainable Vermont

Dec. 16, 2019
VELCO builds New England’s first state-of-the-art, transmission-only, EMP-proof data center.

Tucked on a bucolic hillside—just a few miles from the East skiing mecca of Killington, Vermont, U.S.—is New England’s first state-of-the-art electromagnetic pulse-proof data center. This critical facility embodies the transition underway in the electric utility industry, and the story behind it centers on one electric transmission utility taking steps to drive innovation.

The builder and owner of the data center, Vermont Electric Power Co. (VELCO) was formed in 1956 when local Vermont utilities established the nation’s first transmission-only utility to access clean hydropower from New York. VELCO’s system now includes 738 miles (1188 km) of transmission lines; 55 substations, switching stations and terminal facilities; 13,000 acres (5261 hectares) of rights-of-way; and a 1500-mile (2414-km) fiber-optic network that monitors and controls the entire electric system as well as serves as a key link for consumers’ high-speed data internet access. VELCO is owned by the state’s 17 electric distribution utilities and a public benefit corporation.

Like many industries, electric utilities are creating a pathway for data and analytics to support a more efficient and reliable electric grid. Increased renewable generation, electric vehicle charging, storage development, and more efficient and connected home consumers mean the grid must evolve. For utilities in Vermont, the new electromagnetic pulse (EMP)-proof data center is a critical part of that evolution.

A Need Identified

Constructing the new data center was a feat in itself. Environmental factors of the physical location and Mother Nature played pivotal roles in the design, construction and timeline of the project. In March 2015, VELCO faced the reality its 750-sq-ft (70-sq-m) computer room was not serving the daily needs of the utility in its current state, much less in a growing data-focused world. In addition to the small room of servers, VELCO also had computing and server assets spread out across its campus. The utility set up equipment where space allowed and the systems could be accessed. Years later, these temporary installations still had not been moved to a permanent home.

The utility had two options for building a new data center on its campus:

  1. Find additional space within the current office building.
  2. Construct a new stand-alone building.

The second option of building a new facility quickly advanced, as renovating would further cramp office space and the necessary ballistic and seismic protections would not be affordable. In addition to increasing data processing and storage space, VELCO believed building a facility could support the growth of other Vermont businesses while offering the utility access to a unique revenue stream that ultimately could reduce electric rates for customers.

The new 6900-sq-ft (641-sq-m) data center represents an exciting time in the transmission utility’s operating history. As VELCO continues with its core business of supporting a reliable electric transmission grid in Vermont, and it also is evolving to serve nonelectric customers with its new data processing capabilities.

Once the utility made the decision in the beginning of 2016 to move forward with a new standalone facility, the engineering design began in concert with filings and applications for the civil work and blasting on campus that would be required. To make the building EMP-protected, VELCO determined a new technology using conductive concrete exterior walls for the data center would be the best option. The utility opted for this technology instead of a Faraday cage within the structure because the wall design would not only give EMP protection to the equipment but also provide ballasting, seismic and Category 5 hurricane protection. The proprietary concrete mixture resulted in a shorter design and construction timeline, and it requires less ongoing maintenance.

Construction Kickoff

The site and building construction started in June 2017. Earth work began first, focused on the following:

  • Making accommodations to the existing VELCO campus so parking could be relocated.
  • Maintaining daily inventory deliveries to the existing and active corporate warehouse.
  • Relocating a water line and the main power line to one of the campus buildings.
  • Protecting the primary feeds to the facility as well as the underground fiber.
  • Seismic monitoring for both VELCO and its neighbors within 600 ft (183 m).
  • Developing numerous safety plans to accommodate blasting on a busy corporate site next to a residential neighborhood.

Once the location was cleared and ready for construction, the structural concrete was poured first. This included two building foundations. The data center building is 6900 sq ft and the generator building 950 sq ft (88 sq m). This activity took place over seven weeks using traditional concrete-pouring methods, such as pump trucks and front-offloading concrete trucks.

With the foundations in place, it was time to build the EMP walls. The first step to pouring the walls was to construct casting beds using nonreinforced concrete. Casting bed construction was challenging given the small footprint of the new facility and uneven terrain, which had to be leveled by installing temporary retaining walls and filling them with compacted stone.

The special concrete, which also encloses the standalone generator facility dedicated solely to the new data center, is made of multiple layers of stainless-steel wire mesh and rebar, totaling 12 inches (305 mm) thick. All this unique concrete was mixed on-site rather than trucked in as with the foundation pours. Ten rail cars delivered the proprietary reinforced concrete mixture to a local concrete plant for storage. Once at the plant, it was repackaged into 1-ton sacks and trucked to the VELCO campus. The utility’s water supply was not sufficient for this critical part of construction, so water had to be trucked in and stored in temporary tanks.

Six large casting beds were constructed next to the site to raise the EMP walls. Workers used the shotcrete method (spraying concrete through a hose at a high velocity) to fill in the formed walls. The walls consisted of four lifts, each 3 inches (76 mm) thick, containing rebar, stainless-steel mesh and conductive concrete. The lack of available casting bed space adjacent to the building foundations for the data center and generator building created a challenge assembling the walls in a timely manner.

Mother Nature certainly made construction challenging. There is a saying in Vermont, “If you don’t like the weather, wait five minutes.” When the roof installation began in December 2017, the weather was a hindrance. However, before workers left for the holiday break, they were able to complete the roofs of the generator building as well as metal decking and one coat of shotcrete on the data center roof. Extensive temporary heating and a full tarp was deployed over the entire building to preserve it before the roof was completed in late January 2018.

With the exterior of the data center complete, work started on building out the interior. Redundancy became the name of the game for not only the power supply but also the backup power supplies, cooling systems, admittance security and fiber delivery. Two 800-kW generators were housed in a neighboring EMP-protected building. All service conductors and branch circuits were protected with EMP filters before entering or exiting the data center and generator building. Two isolated fiber-optic feeds were configured in a ring for complete redundancy. Extensive outfitting of the data center and two generator buildings took a year to complete.

Facility Migration

From March 2019 to September 2019, VELCO migrated its IT and telecom infrastructure equipment and services to the new data center. More than 720 strands of fiber-optic cable feed into the building from other buildings and various telecommunication routes around the state, and there is still capacity to add 1500 more strands without requiring a major retrofit. Laid end to end, there is more than 18 miles (29 km) of fiber inside the building.

The new data center not only houses VELCO’s business operational computing needs, it also manages the Vermont transmission grid and the HPCC, which will prove valuable for exponential data growth. The HPCC already is running weather analytics, providing valuable information to the grid operator so energy generation can be balanced with the demand loads during intermittent weather patterns. This cluster of computing enables Vermont to get more value out of the increasing number of renewable electricity generators and reduce its imported energy.

When the utility’s leaders and project managers are designing projects for the transmission system, they consider what affects their operating practices, engineering plans and building methodologies will have beyond their own balance sheet. This sense of responsibility for the greater good influenced VELCO when its corporate systems were nearing capacity in March 2015. Its evolving business model led the utility to explore options that would meet the needs of a sustainable Vermont, including economic sustainability now and in the future. The now completed data center is a key asset that enables VELCO to deliver innovative value to its owners, customers and the beautiful state of Vermont.

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