For Northwest Airlines (NWA), a major airline based in Eagan, MN, energy efficiency is not only a way to reduce energy costs, it is standard business practice. This practice began 20 years ago, when the company initiated its first energy efficiency project in partnership with its utility company, Xcel Energy. Since then, NWA has continued to implement a variety of energy-saving measures 1/m, from energy efficiency studies to equipment upgrades and process improvements. And the results have been impressive.
To date, NWA has saved more than 18 million kWh that’s more than 24 million pounds of carbon, or the equivalent of removing 4,000 commuters from our roads while reducing annual energy costs by more than $1 million, as part of their energy efficiency efforts. In addition, by participating in several rebate programs, NWA has earned more than $1 million in rebates for choosing energy efficient equipment.
A Systematic Solution
The NWA facilities management staff realized long ago that energy efficiency must be more than a one-time upgrade. According to Ron Toward, Northwest Airlines Senior Facility Manager, the airline has always taken a systematic approach to energy efficiency.
“Because our energy systems from lighting to heating to cooling have a dramatic effect on one another, it makes sense for us to continually re-examine our systems to ensure we are taking the best approach,” says Toward. “We also realize that energy efficiency is responsible business practice,” adds Toward.
“Like any organization, we want to run as efficiently and effectively as possible. But we can’t focus solely on the financial impact without considering the well being of our customers or employees.”
Energy Efficiency in Action
The list of NWA’s efficiency measures is long. These are a few that represent total savings gained during the past several years.
Compressed Air
NWA studied the compressed air systems for a 1.3-million-square-foot hangar, which used a 700-hp turbo compressor and two 600-hp compressors to support maintenance operations. As part of the recommendations from its local consultant Air Power Equipment, NWA downsized horsepower significantly, replacing the 600-hp systems with 100-hp compressors and modifying the 700-hp compressor to serve as back up.As part of this compressed air study, the team identified an area in the hangar without a heat source. Using the compressor’s air coils, vents were rerouted to provide a new heat source in the winter without added equipment or energy use.
Lighting Efficiency
After completing a lighting redesign study, NWA upgraded its high-bay lighting fixtures to premium efficiency fixtures in several of its largest hangars. In addition, they converted from T12 to T8 lighting in office and work areas. The transformation drastically improved the work areas for NWA mechanics.
The initial lighting study recommended NWA open the hangar doors during long, bright summer days, using only half of the 120 newly updated fixtures while alternating each row every other day. Turning off half of the fixtures instantly cut energy use in half while increasing visibility substantially.Recommissioning
NWA conducted recommissioning studies to identify low- and no-cost conservation opportunities, particularly in the concourse location and headquarters building. As part of the recommissioning study, NWA identified several problems with many of their variable air volume (VAV) boxes, which are designed to provide constant or variable air depending on the temperature demands of the area. NWA replaced or updated the VAV boxes and instituted proper controls for the group.Prior to the updates, the facilities team received a high volume of calls from passengers waiting in the concourse area, indicating the temperatures were too hot or cold. Now that the updates and proper controls are in place, they have yet to receive a single complaint.
Moving Forward
Toward plans to continue working toward more efficient operations. “My goal here is to make this facility as environmentally friendly and reduce as much energy use as we can,” says Toward. “We’re now in the process of getting LEED certified for all maintenance buildings on the site.” According to the U.S. Department of Energy, compressed air systems account for $1.5 billion per year in energy costs in the United States, and 0.5% of emissions. Many industries use compressed air systems as power sources for tools and equipment used for painting, moving product around the facility, separating and other applications. Optimization of compressed air systems can provide energy efficiency improvements of 20% to 50%.
To learn more about improving compressed air efficiency, contact your utility’s account representative, or visit www.xcelenergy.com/rebates. Search for key words “Compressed Air.” FEJ
