Annual Energy Outlook 2006 with Projections to 2030 - Usinfo.org

Issues in Focusrevolutionize transportation systems and dramaticallyreduce per capita energy consumption [42].While the potential applications of nanotechnologiesare diverse, many issues, including potential impactson human health, remain to be studied. AEO2006does not include potential energy applications ofnanotechnology, because they still are speculative.Transportation SectorThe transportation module in NEMS addresses technologiesspecific to light-duty vehicles, heavy trucks,and aircraft. The majority of the advanced technologiesrepresented reflect improvements to conventionalpower train components, including suchtechnologies as variable valve timing and lift, camlessvalve actuation, advanced light-weight materials,six-speed and continuously variable transmissions,cylinder deactivation, and electronically driven parasiticdevices (power steering pumps, water pumps,etc.). Vehicles powered by batteries or fuel cells arealso explicitly represented in AEO2006, but their penetrationresults largely from legislatively mandatedsales.Transportation technologies not currently includedin NEMS that could potentially become viable marketoptions include homogeneous charge compressionignition (HCCI), grid-connected hybrid vehicles, andhydraulic hybrid vehicles. HCCI—which combinesfeatures of both spark-ignited (gasoline) and compression-ignited(diesel) engines—can operate on avariety of fuels. In the HCCI engine, an extremelylean mixture of fuel and air is autoignited in the cylindervia compression. Autoignition can damage thepistons in spark-ignited engines, but the extremelyhigh air-to-fuel ratio in HCCI engines prevents flamepropagation and results in a much cooler burn. As aresult, HCCI engines are very efficient, with low levelsof emissions that do not require expensiveafter-treatment devices. The fuel properties and cylinderconditions needed for HCCI combustion arewell understood; however, it is extremely difficult tocontrol ignition in multiple-cylinder engines across awide range of load conditions, as needed for vehicleapplications.Grid-connected hybrid vehicles are similar to thehybrid vehicles sold today, except that the batteriesprovide an all-electric range of about 50 miles, and anexternal source to charge the batteries is required.Unlike current hybrid vehicles that use high-powerbatteries to supplement the power of gasolineengines, grid-connected hybrid vehicles are alsodesigned to operate as all-electric vehicles and, assuch, require a much larger battery pack for energystorage, a larger electric motor, and related componentsthat enable them to function over a much widerrange of driving conditions. Although all-electric drivinggreatly reduces the vehicles’ gasoline consumption,the costs of the battery pack and othercomponents are significant. Marketing studies haveindicated that there is a lack of consumer interest in“plug-in” vehicles but that a limited market wouldexist if their incremental costs relative to conventionalvehicles could be reduced to at most $5,000.Hydraulic hybrid vehicles use hydraulic and mechanicalcomponents to store and deliver energy. In ahydraulic hybrid, the gear-driven transmission isreplaced by a hydraulic pump/motor that is also usedto store and recoup energy through the transferof fluid between hydraulic accumulators. Recenthydraulic hybrid prototypes are designed to providelaunch assist in heavy vehicle applications, allowingacceleration with less engine power. The hydraulichybrid system has been shown to provide a 50-percentimprovement in fuel economy at a cost of about $600.Current hydraulic systems are large and heavy, however,and the EPA is funding R&D to reduce their sizeand weight while improving their efficiency.Oil and Natural Gas SupplyIn the oil and natural gas supply area, new technologiesfor the economical development of unconventionalresources could grow in importance. One of themost plentiful unconventional resources is naturalgas hydrates—ice-like solids composed of light hydrocarbonmolecules, primarily methane, trapped in acage-like crystalline lattice of water and ice.The 1995 National Oil and Gas Resource Assessment,conducted by the USGS and the Minerals ManagementService, produced the first systematic appraisalof in-place natural gas hydrate resources in U.S.onshore and offshore regions [43]. Its mean (expectedvalue) estimate of in-place natural gas hydrates offshorein U.S. deepwater areas was 320,000 trillioncubic feet, and its mean estimate of in-place naturalgas hydrate resources onshore in Alaska’s NorthSlope was 590 trillion cubic feet. In comparison, totalU.S. natural gas production in 2003 was 19 trillioncubic feet, and year-end 2003 reserves were 193 trillioncubic feet. According to these estimates, ifnatural gas hydrate resources could be developed economically,they could supply U.S. natural gas needsfor many years.Commercial production of natural gas hydrates hasnot yet been attempted. Short-term production testsEnergy Information Administration / Annual Energy Outlook 2006 43