Green Is this Season's Color
On the commercial buildings side, researchers are breaking new ground in development of "intelligent," energy-efficient structures for businesses.
Beginning with the nation's largest retailer and spreading to hospital campuses, military bases and private residential developments, going "green" is becoming fashionable in the commercial buildings sector. Oak Ridge National Laboratory has been right there all along.
With the company's stores commanding about 1% of all commercial floor space in the United States and an energy bill in the billions—as well as a well-earned reputation for trimming costs—saving energy has become a priority for the retail giant Wal-Mart. The company has determined that employing energy-saving materials and technologies in its new stores stamps yet another whistling smiley-face—the staple of Wal-Mart's advertising campaign—on the company's bottom line, says Mike MacDonald, a researcher in Oak Ridge National Laboratory's buildings technology program. Wal-Mart has also publicly committed to major reductions in their carbon footprint and increased use of sustainable building practices.
MacDonald has been working with Wal-Mart since 2005 to conduct thirdparty technical evaluations of technologies the company is employing at one of two "green" Wal-Mart Supercenters—this one in McKinney, Texas. There the company tests a variety of energy saving and generating innovations, from reflective roofing to solar panels to windmills to LED lighting to hybrid solar lighting developed at ORNL. Driven by data from ORNL's analysis, several energy saving technologies have been rolled out in traditional Wal-Mart stores.
"Wal-Mart is trying to push the technology envelope all the time," says MacDonald. "They force the manufacturers to innovate. They are pushing their suppliers to go green in their whole operation. Wal-Mart carries a pretty big stick."
In addition to Wal-Mart, ORNL works with a number of companies investing in ways to become less dependent on traditional energy sources.
One important area of commercial buildings technology research at ORNL includes integrated cooling, heating and power (CHP). Approximately two-thirds of the fuel used to generate electricity in conventional power plants is wasted in the form of discarded heat. CHP allows businesses and industry to use recycled waste heat from power generation for heating and cooling onsite, rather than depending entirely on the electric power grid. CHP systems improve total efficiency of the systems 78% to 85%.
Now being deployed in large complexes such as hospitals and school systems, ORNL researchers believe these CHP systems could service apartment and business office complexes and even multiple homes in a neighborhood setting. Nationally, the systems produce a total of 87 gigawatts of power, close to the Department of Energy's established goal of 92 gigawatts by 2010. ORNL is working with companies including United Technologies, Honeywell and Burns & McDonald to develop and test the systems both in the lab and in the marketplace.
Control over energy sources, energy use and energy management is key to the future of new buildings technologies. New technologies by themselves do not make an energyefficient future, say ORNL researchers, but integrating those technologies into intelligent, comprehensive systems promises to change the way buildings of the future are designed, constructed and equipped.
This is the thinking behind several new technology strategies ORNL is pursuing in support of DOE's programs to accelerate transformations in the buildings sector that will reduce energy use, climatechanging emissions and environmental sustainability. These pathways include developing new renewable energy systems, building materials, construction techniques and intelligent energy systems.
Under license from ORNL, hybrid solar lighting systems that pipe natural light into buildings' interiors—via fiberoptic lines emanating from dish-shaped solar trackers—are commercially available today. Researchers at ORNL hope to continue technology advancements so systems in the future can satisfy lighting requirements all the way into the core of large buildings and utilize excess solar energy to generate power. Geothermal (or ground-source) heat pump systems for commercial building space conditioning and water heating have been available for several decades, but recent technology advances now enable the construction of buildings so energy efficient that ground loops constrained within the new building's excavation may be feasible, eliminating the expense of extra trenching and drilling for the ground loops the systems typically require.
Another technology pathway aims to make buildings "smarter" about the energy needs of individual building occupants. This approach involves knowing where the people are and what they are doing, says Jeff Muhs, strategic planner for ORNL's Engineering Science and Technology Division. "We want to focus on the people and provide them with personalized energy services," Muhs says. "In your office you need more light for some tasks than others, and if you are away the office needs none at all. The same is true for temperature, humidity and fresh air control. What we are trying to do is eliminate waste—and we believe we can do that without sacrificing personal comfort or productivity."
Muhs envisions an RFID tracking system that would allow people to interact with buildings and would use anticipatory algorithms to learn occupants' schedules and preferences with respect to lighting and space conditioning. By tapping into ORNL's multidisciplinary pool of researchers, he says, the initiative will use expertise in sensors, controls, computing, wireless communications and machine vision to develop these intelligent systems.
While exciting new systems for buildings lie tantalizingly within reach, other concepts are somewhat more futuristic. New technology called automated free-form construction holds the potential of transforming conventional building practices and architectural design. ORNL robotics researchers envision homes and commercial buildings someday being built using "CAD-to-fab" processes and less expensive, locally available materials made from natural, recycled and/or bio-based sources.
ORNL's capabilities in advanced materials, ultrascale computing and advanced energy systems along with a history of integrating multidisciplinary basic and applied R&D and partnering with research universities and industry, make the Laboratory an ideal place to spearhead such transformational research.—Larisa Brass
Web site provided by Oak Ridge National Laboratory's Communications and External Relations