Greenest data centers: What works and what doesn’t

Photo voltaic arrays. Sod roofs. Reflective white membranes. These are some of the far-out techniques that architects are using to build the nation’s greenest data centers.

But the managers of these data centers say some of the most effective ways of cutting back electricity usage -- such as raising the computer room temperature a few degrees -- also are the simplest.

A peek inside the nation’s greenest data centers shows that these facilities are a mix of high-tech and low-tech, innovative and obvious ways of cutting back on electricity and creating more environmentally friendly IT operations.

Building green data centers involves a fair amount of gamesmanship.

Some of the clever ways that architects get new data centers certified by the U.S. Green Building Council have less to do with improving energy efficiency and more to do with other environmental goals such as reducing water usage. Often it’s native landscaping, rainwater recovery systems, waterless urinals and bike racks that earn data centers enough points to qualify them as "green."

To build a green data center, you need "a team that works together and is incredibly creative," says Kath Williams, a Montana green building consultant and former vice chair of the U.S. Green Building Council. "It’s amazing where you can find the energy savings."

Interest in energy-efficient data centers has grown significantly in the past two years, as electricity bills have soared. Additionally, more data center operators are concerned about the effects of greenhouse gasses produced by the most common ways of powering computers and network gear: coal-burning plants.

Data centers are among the hardest commercial buildings to make energy efficient because the computer systems they house require so much electricity and give off so much heat. About half of the electricity consumed in a data center is from the power and cooling infrastructure that supports IT equipment, according to the U.S. Environmental Protection Agency (EPA).

"It’s extremely difficult" to build a data center that meets the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) standards, Williams says. "For data centers, the challenge is the energy load."

Earlier versions of the LEED standards excluded the so-called process load, which is the amount of energy used for data processing. But the latest versions of the LEED standards --Version 2.2 and higher -- don’t allow this exclusion.

"Now it’s the complete energy use in the building, with all the computers running 24 by 7," Williams says. "Every bit of energy in that building has to be accounted for."

Feds lead green movement

At the forefront of the green data center movement is the U.S. federal government, which has been required by law to measure and track energy usage in its buildings for more than 20 years.

"We can look at the energy consumption of all our facilities back to 1985," says Kevin Kampschroer, director of research and expert services in the Office of Applied Science at the Public Buildings Service, an arm of the General Services Administration that owns and leases office buildings for more than 1 million federal workers. "We know exactly what’s going on in our buildings, and we manage it at a national level. When we see significant increases, we send in a specialized team to see what we can do in this building."

Because of its advanced energy metering and management, the Public Buildings Service is "operating at about 9% less energy cost than the private sector on average, per building around the country," Kampschroer adds. That number includes hundreds of historic properties designed without energy conservation in mind.

The federal government has set aggressive targets for reducing the energy consumption of its buildings, including its data centers.

"Our goal is that by 2015, we need to reduce our total energy consumption across the board by 20%," Kampschroer says. "That’s hugely aggressive because between 1985 and 2005, we already reduced our total consumption by 30%."

Among the nation’s first data centers to be certified as silver or gold by the U.S. Green Building Council’s LEED program are data centers operated by the EPA, National Oceanic and Atmospheric Administration (NOAA) and Energy Department.

The National Oceanic and Atmospheric Administration’s Satellite Operations Facility in Suitland, Md., has soil and plants on its roof to improve insulation.

The General Services Administration, which manages office buildings for the U.S. government, in 2000 adopted a policy that all of its new buildings would be LEED certified.

"We have 20 buildings that have been LEED certified. Out of our inventory, that’s 100% of the new buildings that have come online," Kampschroer says. "We have 80 [LEED] buildings in the works."

What works to cut usage

The newest green data centers share many features: They’re built using locally supplied and recycled materials; waste is minimized during construction; lots of windows provide extensive natural lighting; and fluorescent lighting with dimmers is used throughout. These buildings have occupancy sensors so that lights and temperature automatically adjust when no one is in the room. Another common feature is raised flooring with under-floor heating and cooling used throughout the buildings, not just in the computer rooms.

The EPA’s National Computer Center (NCC) at Research Triangle Park, N.C. -- a 95,322 square foot, 200-employee facility -- is a LEED Silver building. To get that certification, architects rotated the building so that the offices and lobby face south to allow the sun to help heat the building.

"The current orientation does take advantage of the sun, but in the summer that adds to the heat load," says James White, a physical scientist with EPA’s Office of Administration Resources Management at Research Triangle Park. "One of the things we learned from this is to focus on really good glass glazing for the windows. This keeps your lighting factor up but reduces the heat load."

Architects also cut the size of the building by 20% from its original footprint, and designed in the capability to expand it later rather than building in extra capacity.

"One of the big buzzwords is rightsizing," White says. "You need to really focus on sizing the building correctly and balancing loads so you don’t build in unnecessary energy systems."

NCC’s most innovative feature is the special solar panels on its roof, which offset about 5% of the building’s electric usage. The building’s roof is one of the largest photovoltaic installations on the East Coast. The photovoltaic system converts the sun’s light into electric energy and feeds it directly to the building. Another benefit of the roof is that it provides extra thermal insulation. It not only generates electricity but it mitigates unwanted radiant heat gain.

NOAA’s Satellite Operations Facility (NSOF) in Suitland, Md., also has an innovative roof. The building has one of the largest so-called "green" roofs in the Washington D.C. area. It has soil and native plantings on the roof much like a sod shanty from pioneering days.

"The building is very unique," says Paul Pegnato, NSOF project manager. "The architect had this vision of a sloping landscape. So when you start on the north side and are walking across the landscape, you’re walking across the roof without even knowing it."

NSOF’s green roof helps reduce storm water runoff and improves the building’s insulation. But NOAA has run into some problems maintaining the roof’s plants during periods without rain.

"We’ve had some droughts out here, and there isn’t a lot of experience here with green roofs," Pegnato says. "We’re fighting with that. It takes a lot of commitment to maintain the landscaping."

The landscaped roof helped NSOF, a 60,000 square foot building with 549 employees, receive the LEED Gold rating in early November.

The Air Force Weather Agency is building a 182,000-square-foot building at Offutt Air Force Base in Omaha, Neb., that is aiming for LEED certification. The building, which cost $29.7 million, houses supercomputers that process more than a terabyte of weather information each day and transmits it to pilots around the world

The building for the Air Force Weather Agency in Omaha, Neb., has a reflective white roof with extra insulation and faces west to reduce heat in the summer.

The Air Force is using several design tricks to get the building certified under Version 2.1 of the LEED standard.

"It’s unclear if the building with its large, powerful computers could get certified under Version 2.2…because 2.2 requires the entire energy load to be considered," says Lt. Col Ron Dunic, Chief of AFWA Headquarters Transition Programs. "We tried to get as much of the energy efficiency in other parts of the building to reduce the overall energy footprint of the building."

Some of the tricks the Air Force used include angling the building to face the west rather than the south to reduce summertime heat. The building also has a reflective white roof with extra insulation to keep the sun from warming up the building too much.

"One of the big things is the raised floors," says Bruce McCauley, chief of construction management at Offutt. "The three-foot raised floor allows us to distribute the wiring and the air conditioning and heating under the floor. We do get some energy efficiency by not having ducts."

The Air Force hopes to get points on the LEED certification process for features that are outside the building itself. For example, the new building is alongside an abandoned runway. So the Air Force reused the runway for the parking lot and will get points for recycling existing materials and reducing construction waste.

AFWA’s data center is at the edge of a secure military base, so all the construction-related trucks would have to drive through the main gate, go through a security checkpoint, and be escorted to the site. The Air Force temporarily moved the base’s fence so that the construction site was outside of the base’s border during construction. Now the Air Force hopes to get a LEED credit for reducing construction-related transportation.

"Those credits will help us substantially" with certification, says Williams, who is a consultant on the project. "I’m confident that we’ll get it LEED certified, but barely. It’s been a real challenge to get the building to that level."

Lessons learned

Operators of these cutting-edge green data centers say one of the primary ways of reducing electricity usage is adjusting the air conditioning. By merely raising the computer room temperature a few degrees, they are able to reduce electricity usage by as much as 10% or 20% annually.

The EPA, for example, turned off six of the 14 air conditioning units at the NCC last year and was able to reduce the facility’s energy usage by 9%.

"Over the last 12 months, there’s been a 20% reduction in energy usage in NCC," White says. "A lot of that came from cutting down on the computer room air conditioning units."

NOAA ran into the same problem of IT staff running the NSOF’s air conditioning too low.

"IT personnel thought the computer room air conditioning was working when you walked into a room and it felt like an ice box," Pegnato says. "You don’t need an icebox to keep computer equipment running correctly. Computer equipment typically needs the 70 to 72 degree range. So why are we always producing air in the low 60s?"

The Public Building Service is fighting the "icebox" mentality at data centers around the country.

"One of the lessons we’ve learned is that there is a tendency to run the data center with too much cooling," Kampschroer says. "In one example, we recommended that they keep the set point at 68 degrees, but they were keeping it at 58 degrees out of fear of what would happen if the power went out. What people don’t realize is that the computer equipment that’s out there today is less sensitive to fluctuations of temperature than IBM mainframes from 25 years ago."

Adjusting the air conditioners water chillers by just a few degrees can reap huge energy savings. And that’s something that IT departments can do today to help make their existing data centers greener.

"One of the biggest impacts on energy is at the air conditioner chiller level," Pegnato says. "They consume a major amount of electricity. By upping that chilled water temperature one degree, it has to work a lot less."

Why it all matters

Building green data centers -- or retrofitting existing data centers with green features -- is likely to be top-of-mind for CIOs in 2008. That’s because the amount of electricity that data centers use is on the rise.

The amount of energy used by data centers nationwide more than doubled between 2000 and 2006, EPA asserted in a report to Congress this summer.

EPA estimates that the nation’s servers and data centers consumed about 61 billion kilowatt-hours of electricity in 2006 for a total electricity cost of about $4.5 billion. This is more than the electricity consumed by all the nation’s color televisions and similar to the amount of electricity consumed by 5.8 million U.S. households.

EPA estimates that national energy consumption by data centers could nearly double again between 2006 and 2011, reaching more than 100 billion kilowatt hours and costing $7.4 billion annually.

In the future, the greenest data centers are going to be the ones with the most business, experts say.

"The cost of energy is going up everywhere," Kampschroer says. "Given the amount of energy consumption that’s done in data centers…the operators of data centers that are the most energy efficient are going to be the most cost effective and they are going to get more business."

Even Wall Street is paying attention to the construction of green data centers.

"The financing of green buildings is being preferred in the financial markets with better interest rates because the likelihood of a green building holding its value over the next 30 years is much higher," Kampschroer says. "If you change the financing even by a quarter of a point, it makes a huge difference in the cost-effectiveness of a new building. It really comes down to this: Do you want your data center to be competitive in the future or not?"

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Copyright © 2007 IDG Communications, Inc.

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