Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportations Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
passengers with a range of over 7,000 miles (IPCC, 1999; NASA, 1997), but smaller
variations of the aircraft also are possible. Initially these aircraft will probably provide
services to large and distant urban centers that are associated with dense air traffic, such
as between New York and London or Los Angeles and Tokyo. Because of the unusual
shape of these aircraft, changes in infrastructure will be required to accommodate these
aircraft (ADL, 2000).
Magnitude and Timing of GHG Reduction
The application of drag-reducing surface films is anticipated to decrease fuel usage by up
to 1.6 percent, while multilayer panels used to reduce surface friction across the wing are
expected to reduce fuel consumption and emissions between 6 to 10 percent. Use of wing
tip devices can reduce fuel use by 1.7 to 2 percent for blended winglets (Morris, 2009,
Reneaux, 2004) and up to 10 percent for spiroid winglets applied to smaller aircraft
(Ostrower, 2008). Additional testing is being implemented for larger aircraft to quantify
fuel consumption improvements associated with spiroid winglets.
Cost-Effectiveness
As mentioned earlier, the high cost of fuel is anticipated to drive the development and
application of these technologies, as they will reduce operating costs, although the costeffectiveness
of each technology may vary. For example, wing tip retrofit kits cost
approximately $1 million to install, which would require less than six years to break even
based on a fuel cost of $3.33 per gallon. The payback period for other technologies that
have yet to be commercialized is uncertain, as cost data are not readily available. Blended
wing bodies are anticipated to entail a considerable price premium of $30 to $60 million
per aircraft, including development costs.
Cobenefits
Since these devices primarily improve efficiency at high speeds (i.e., high-altitude
operation), any benefits in terms of pollutant reduction are not expected to be significant.
Feasibility
Wing tip devices are commercially available and require little assistance from the policymakers
to promote their use. Accelerated adoption of wing tip devices may be
encouraged through voluntary programs such as the EPA’s SmartWay Program. Grooved
adhesives and multi layer panels are likely to be less viable than other technologies
presented in this section, due either to short lifetime (adhesives) or uncertain benefits
(panels).
Tests of wing design changes that reduce friction through laminar flow have been
encouraging, but at this time these designs have yet to be incorporated into commercially
available aircraft. Similarly, BWB aircraft have performed well in model tests
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