Stewart has put all his knowledge to work in overseeing the building of five 50,000-square-foot data center buildings on a 30-acre site in Culpeper, Va., about 90 minutes southwest of Washington, D.C.
Based in Miami, Terremark decided to build in the Beltway because it had several federal government customers that needed better access to their equipment. The first building has been constructed, with the others to be built as demand dictates.
The Culpeper site has several interesting features. First, Terremark doesn't use battery-based uninterruptible power supply (UPS) systems. Instead, it has installed 11 900-kVA flywheel UPSes.
While some worry about the reliability and ride-through time of flywheels, Terremark has used them for a while, and Stewart said the company has yet to confront a problem.
"I don't know any data centers that can go a minute or two without cooling," he said. "If they need ride-through time for 10 or 15 minutes and they're not running their air handlers on the UPS, they're going to have to shut their stuff down anyway."
How does that translate into savings? Stewart said capital costs are similar, but he won't have to replace strings of batteries every three to five years, which can cost $100,000. Also, flywheels don't take up as much real estate as batteries. Go into a large data center that runs battery-based UPSes and you'll likely find a separate room or rooms that contain just battery strings.
"We're in the business of selling square footage, not consuming it ourselves," Stewart said.
Also at the Culpeper site, Terremark will use water-side economizers, which use the naturally cold air outside to cool the water that feeds into data center chillers. Stewart said that these are a better fit in Culpeper than in Miami, where the weather is much warmer year-round. In Culpeper, he expects to get three to four months of free cooling. For an additional month on each side, he expects to supplement the more costly mechanical refrigeration with free cooling at night.
Though Stewart isn't certain exactly how much the free cooling will save him until all the buildings have been built and filled, he said that the monthly energy bill in Miami is $630,000, and chiller costs are about 40% of that. If Culpeper's costs are similar, that could mean more than $1 million in savings every year.Broad skill set pays off
When it comes to filling up the new Culpeper site with customers, Stewart's broad experience can help there, too.
"When I go to meetings with potential customers, I can cover full services from power densities to security to network connectivity," he said. "My background allows me to sit in a room with a customer and be able to go down the whole checklist."
And it's not just a benefit to him. His facilities engineering staff of about a half-dozen people can capitalize on it as well.
"He has a lot of knowledge in different parts of the company," facility engineer Albert Ramos said. "He'll teach me something about part of the company that I don't have direct contact with."
In 2003, Stewart joined Terremark, after a 25-year tenure in the U.S. Coast Guard, where he got his electrical engineering degree. He also got his master's degree in electrical engineering at the Naval Postgraduate School and his master's in business administration from Monmouth University.
"He's a commanding presence," said Ed Jacobson, the president of Terremark technology contractors and Stewart's boss. "He's a bright guy and gets things quickly. With his 25 years in the Coast Guard, he's organized and is good at the rank-and-file order of things."