News

Green Data Centers Bring Environmental, Financial Gains
January 28, 2009

By 7 x 24 Exchange
Appeared in Building Operating Management/FacilitiesNet

Everyone knows that data centers consume tremendous amounts of electricity. In fact, data centers used 61 billion kilowatt hour (kWh) of electricity in 2006, according to the National Data Center Energy Efficiency Information Program (NDCEEIP). That is double the amount of energy used in 2000 and represents 1.5 percent of all U.S. electricity consumption. NDCEEIP, which is a joint program of the Department of Energy (DOE) and the Environmental Protection Agency (EPA), predicts growth in energy consumption by data centers will continue to skyrocket by 12 percent annually. EPA’s projected energy consumption by data centers for 2008 is more than 80 billion kWh.

In its August 2007 report to Congress, EPA’s ENERGY STAR Program estimated that state-of-the-art technology could drastically reduce energy use in many data centers. Even if data centers were only 10 percent more efficient, they could yield energy savings of 10.7 billion kWh by 2011, according to ENERGY STAR calculations.

Energy is at the heart of a burgeoning effort to make data centers greener. But the word “green” has multiple meanings when applied to data centers.

On the one hand, it refers to efforts to minimize the environmental impact of business activities. Boardrooms want to be perceived as respectful of Planet Earth, so they are taking steps to reduce energy use and use more sustainable materials in concerted efforts to reduce their carbon footprints.

But green is also the color of money. Data centers are crucial to global business. Billions of transactions travel through them daily. And the high cost of down time requires corporations to make substantial investments in facility infrastructures to ensure appropriate levels of reliability.

The challenge for facility executives is to reconcile these diverse meanings of green — data centers that are more environmentally friendly, that are cost-effective and that meet reliability targets.

Growing Interest
The topic of data centers has drawn plenty of attention from groups interested in energy efficiency and green design.

R. Stephen Spinazzola, vice president of RTKL’s Applied Technology Group, says he believes the corporate movement to make data centers more energy efficient and greener started in 2004, as utility costs began skyrocketing. “Today, there just aren’t that many places offering cheap electricity,” he says.

Although no Leadership in Energy and Environmental Design (LEED) standard exists for data centers, Lawrence Berkeley National Laboratories is working on an alternate LEED process for mission critical facilities. The American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) has Technical Committee 9.9, Mission Critical Facilities, Technology Spaces and Electronic Equipment tackling data center issues. The Department of Energy has a Data Center Energy Efficiency Program underway and a new software tool for savvy facilities executives. ENERGY STAR began collecting data from more than 200 data centers in mid-2008. The goal is to gather monthly energy use information, so that ENERGY STAR can develop a rating system for data centers as part of EPA ENERGY STAR’s Portfolio Manager tool.

Section 453 of the Energy Independence and Security Act of 2007 requires DOE and EPA to designate a consulting organization and to coordinate a voluntary national information program for energy efficiency in data centers. DOE and EPA are currently defining a role for the organization.

The goal of all this activity is to develop consensus standards and benchmarks for data center energy efficiency. While none currently exist, that is not stopping corporations from creatively pursuing certification under the LEED for New Construction (NC) program.

“In the last few months, we’ve seen much interest by clients in having their data centers LEED certified,” says Vali Sorell, PE, associate partner of Syska Hennessy Group, Inc. “Because energy is becoming so expensive, more companies are asking us about the LEED process and sustainable design processes. In fact, we have several data center projects that are fully committed to LEED certification.”

One of the pioneers in the effort to achieve LEED status for data centers is the 87,000-square-foot Highmark Data Center in Harrisburg, Penn. That facility received a LEED-NC Silver certification from the U.S. Green Building Council in 2006. The actual data center occupies 28,000 square feet of the facility, which also has office and support area space to process hundreds of thousands of health insurance claims daily, which pour in from more than 100 hospitals and 15,000 health care providers.

“Highmark had four primary business drivers that led to the design and construction of the new data center,” explained Lowell Starling, vice president of infrastructure management at Highmark. “They were to improve reliability and security, demonstrate technology as a differentiator in the market, as well as display Highmark’s commitment to being a good neighbor.”

Designed by RTKL, the data center is located directly above the mechanical plant, with chilled water piping located underneath the floor, so flooding concerns are lessened. The facility takes advantage of energy-efficient HVAC equipment and the building is commissioned regularly. Its green strategies include collecting rainwater from the roof for cooling tower make-up water and non-potable uses.

The desire to be greener converges with financial goals to drive the increased interest in energy efficient data centers, says Christopher Johnson, senior vice president, Syska Hennessy Group, Inc. “The astute client wants to minimize the total cost to own and operate the facility,” he says.

David Schirmacher, vice president within corporate services and real estate at Goldman Sachs, concurs. “The bottom line is that a green data center is more cost effective. The primary focus of a green data center is to use less energy, which is a significant expense. By building green facilities, we can reduce operating expenses and be more responsible from an environmental perspective at the same time.”

Efficiency and Reliability
But does greater energy efficiency mean giving up reliability? “There are creative opportunities to maintain a data center’s resiliency and increase its efficiency,” says Schirmacher.

Simplifying data center mechanical and electrical systems can improve performance and reliability by reducing points of failure. When energy-conserving systems require complicated sequences to operate, the potential for human error increases dramatically, says Sorell. “The simpler the energy efficiency measures, the less likely the data center will experience a crash.”

While no standard exists yet for green or energy efficient data centers, facility executives do have some metrics that can be applied now. The two most popular are power usage effectiveness (PUE) and data center infrastructure efficiency (DCIE), which is the reciprocal of PUE, expressed as a percentage.

“PUE is a rather imprecise definition of how much energy is being consumed by the computer center, divided by how much is getting to the computer,” says Johnston. “The question becomes where to measure the energy that goes to the computers.”

Schirmacher offers a simplified example. “If a server uses 1 watt of power and the supporting mechanical equipment for cooling and conditioning the center uses another watt, then the PUE is 2.0,” he says. Many older legacy data centers operate well over 2.0, while energy-efficient centers operate at PUEs in the range of 1.5 or better.

Johnston says he knows of a data center with a PUE of 1.6 in its worst month and an annual PUE of about 1.45, for a DCIE of 69 percent. “We have a new 7.2 megawatt data center under construction in a high desert location that we expect will have an annual PUE of 1.3, for a DCIE of 77 percent,” he says. Some of the most efficient data centers are approaching PUEs of 1.2 in ideal climates.

“But we are tiptoeing around an 800-pound gorilla, which is the energy efficiency of the computer equipment that the owner employs,” Johnston says. “If the 1 in a PUE of 1.5 is the computer equipment, then all our engineering efforts are on the 0.5 side.”

ENERGY STAR Developments
“PUE is a commonly accepted metric, but it is not perfect,” says Michael Zatz, manager of the U.S. EPA’s ENERGY STAR Commercial Buildings program, which is gathering the data center statistics. “The ideal metric would take into account the output of the data center. But we can’t afford to wait for a perfect metric. We need to start gathering data so we can develop a benchmark to be used by the industry.”

Currently, there is no consensus on output measurement. So ENERGY STAR is going with average PUE, based on 12 months of data reporting. From now until the middle of next year, Zatz will be working with 240 data centers that agreed to supply ENERGY STAR with that information monthly. Once all information is in, development of the ENERGY STAR rating for data center energy efficiency will proceed.

The data centers’ input will help ENERGY STAR develop a rating system, based on a 1 to 100 range.

“A score of 50 would be average,” says Zatz. “At 75 or higher, the data center would qualify for the ENERGY STAR.” Currently, EPA is hoping to launch the ENERGY STAR rating for data centers in its Portfolio Manager tool by early 2010, provided, of course, that most data centers signed up for the program actually submit their energy use data.

While ENERGY STAR and others work to develop standards and benchmarks for data centers, a variety of tools and best practices that facilities executives can use today are surfacing. For example, DOE’s Data Center Energy Profiler (DC Pro) Version 1.0 completed beta testing and was released in late 2008. DC Pro is an online software tool that allows facility executives to see how energy is being used in their data centers and how they might save energy and money.

The downloadable tool provides an overview of energy purchases, data center energy use, savings potential and a list of actions to realize those savings. The source energy factor for each energy stream can be customized to adjust for electricity produced from cogeneration and renewable sources. A PDF report of the results can be produced.

ASHRAE’s TC 9.9 authored a series of books addressing issues and best practices for data centers, including Best Practices for Datacom Facility Energy Efficiency, published in 2008. The book includes chapters on environmental criteria, mechanical equipment and systems, economizer cycles, airflow distribution equipment, datacom equipment efficiency, liquid cooling, total cost of ownership and emerging technologies.

Obstacles to Efficiency
Amidst all this progress towards more energy efficient data centers, obstacles still exit. One obstacle, Zatz says, is human nature’s preference for doing things as they’ve always been done. “When you are looking for energy efficiency and examining operations in a building, you need a different mindset,” he says. “You have to be open-minded to do things in a different way and be willing to push the envelope.”

The other people problem Zatz says he sees is the lack of interaction between the IT department and the facility staff. Johnston agrees, “The IT people often are not willing to spend additional money to increase energy efficiency, because the budget for the electric utility bill comes under the facilities department.”.

Greening a data center also means scrutinizing resources beyond electricity. For example, Advanced Data Centers also is trying to use LEED as a template for its facilities. In its McClellan, Calif., data center, redundant water for the cooling towers is tapped from a graywater well close to the site. Water from the gray-well is filtered and used as the cooling towers’ primary water source, with the local water district’s domestic water supply as a backup option. Another filter system removes dissolved solids in the cooling tower blow-down, allowing its reuse as well. By doing so, the data center eliminates the blow-down water’s impact on the sanitary sewer system and helps contribute to a significant reduction in its annual water use.

Sorell suggests site selection, air-side economizers and evaporative cooling, in locations such as the northwest where the concept is viable, are other options data centers today are choosing. “Energy efficiency needn’t be fancy,” Sorell says. “In fact, the simplest solutions are the safest.”

Some facility executives are upgrading the filters in air handlers to remove more particulate. “There are climates where the data centers can use free cooling with outside air most of the year,” says Johnston, who knows of one data center that operates cooling only 500 hours a year.

He also suggests arranging electrical equipment so that it runs at high capacity, because that’s the level at which it operates most efficiently.

Johnston says that facility executives should use modular construction principles, building scalable systems as needed. “You want to add just before you need additional capacity, because in computers, a generation is three years.” That means the mechanical and electrical equipment, which typically has a 20-year service life, will last through seven technological changes of computer equipment.

Other green measures include using materials with high recycled content. And choosing suppliers “close to the site so we’re not burning through our savings in huge transporting charges,” says Spinazzola.

Is it worth all the effort to develop greener, more efficient data centers? “Some would argue that no data center should be considered green because of its high energy use,” says Zatz. “But data centers can have a positive environmental impact. Energy efficient operations can significantly reduce their carbon footprints. And a data center may allow 1,000 people to telecommute instead of driving to an office, so the office footprint can be smaller.”