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Total Vehicle Sales

13,618 13,274 13,274 13,836

13,836 14,777 14,780 14,892 14,893 Source: Energy Information Administration, National Energy Modeling System runs AEO998.D100198A and CCTTTRN.D033199A.

Table 32. Light-Duty Vehicle Fuel Consumption by Fuel Type, 1997-2020 (Trillion Btu per Year)

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Distillate Fuel

7.43

Methanol

1.17

6.93 31.35

11.14 12.48

33.15

Ethanol

Compressed Natural Gas ..

Liquefied Petroleum Gas

Electricity

Hydrogen

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46.89 90.86 170.03 193.32 31.27 51.04 50.77 77.38 75.63 108.67 108.38 0.53 17.84 17.80 30.10 29.91 51.13 50.62 74.32 74.08 11.91 108.84 108.84 172.90 172.80 234.42 234.17 294.65 294.56 20.97 60.50 60.45 104.49 104.41 154.62 154.57 199.48 199.41 0.29 2.79 2.79 39.94 39.91 83.13 83.06 147.38 147.39 0.00 0.00 0.00 0.01 0.01 0.10 0.10

Total

13,944.59 15,745.80 15,747.62 16,719.61 16,711.31 18,096.17 18,070.99 19,598.83 19,589.17 Source: Energy Information Administration, National Energy Modeling System runs AEO998.D100198A and CCTITRN.D033199A.

Table 33. Transportation Sector Carbon Emissions by Fuel Type, 1997-2020

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Source: Energy Information Administration, National Energy Modeling System runs AE0998.D100198A and CCTITAN.D033199A.

Emissions issues may pose problems for direct injection diesel vehicles. Advances in diesel technology have significantly reduced their noise and emissions of particulates, but high levels of nitric oxides and particulates still present significant health problems. EPA is currently revising its NO, and particulate emissions standards as mandated by Congress under the Clean Air Act Amendments of 1990, and recent regulations passed by the California Air Resources Board are expected to eliminate diesel technologies from further consideration as solutions to higher fuel economy unless they use advanced catalysts and/or new types of low-sulfur or reformulated diesel fuel

Emissions issues are especially problematic for direct injection diesel technologies. Reduction of both NO, and particulates has proven difficult, because reduction of one often increases the emissions of the other. Particulate traps are expensive and marginally effective in emissions reduction. Advanced catalysts are being developed, but they are very expensive. Two different avenues of catalyst research and development are currently being pursued: Argonne National Laboratory has developed a plasma membrane that can separate NO, emissions into pure nitrogen and oxygen, and Daimler-Chrysler has developed an emissions after-treatment procedure that shoots a fine mist of urea into the exhaust, chemically changing NO, to nitrogen and oxygen. Both catalysts are in the early stages of research. Advanced low-sulfur, low-benzene, and reformulated fuels in combination with advanced catalysts are currently being explored, and Fischer-Tropsch fuels (derived from refinery waste products and natural gas) also are potential candidates for use with advanced diesel technologies. Studies have shown that these advanced diesel fuels and derivatives can reduce both NO, and particulate emissions by as much as 80 percent. At present, however, the fuels are not cost-competitive with either gasoline or diesel fuel.

Current diesel technology may not be accepted quickly by the public because of the reliability issues that arose for diesel technology during the 1970s and 1980s. This is evident from the current lack of sales for direct injection diesel vehicles from Volkswagen and the current low level of sales for diesel light-duty vehicles, which made up only 0.01 percent of all light-duty vehicle sales in 1997.

It is also important to note that electric, fuel cell, electric hybrids, and turbo direct injection vehicles are in direct competition with each other for market share. Model runs with the turbo diesel direct injection technology initiative but without the CCTI tax incentives described in Chapter 2 resulted in a drop in fuel cell vehicle sales of almost 2,000 units (42 percent) in 2010. In the CCTI tax incentives case, turbo diesel sales were 50,000 units (28 percent) lower in 2010 than projected in the turbo diesel direct injection technology case.

Heavy Trucks

Analytical Approach

The NEMS freight truck module is a stock model that includes existing and future fuel-saving technologies as well as alternative-fuel vehicles. The model uses projected sales of freight trucks, fuel prices, and output for selected industries from the macroeconomic module to estimate freight truck travel demand, purchases and retirements of freight trucks, and fuel consumption. Sales of new trucks are estimated according to the assumed market penetration rates for existing and future technologies, competition with other technologies, sensitivity to fuel prices, and fuel economy improvement. Relative fuel economies are used to determine the market share of new truck purchases for each technology in each year of the projection period. Capital costs are converted to an equivalent fuel price at which each technology is considered cost-effective, based on an assumption of a 3-year payback period with a 10-percent discount rate applied to the average distance traveled per truck.

For the CCTI analysis case, the following characteristics of heavy trucks were added to the available technology choices:

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Engine Efficiency. Currently the best engines have nominal efficiencies of 46 percent. In order to achieve the CCTI goals, it was assumed that engine efficiencies would be increased to 55 percent or higher (an improvement of about 20 percent). The direct injection diesel engine is the most viable near-term engine technology expected to be commercially available by 2006. For this technology to be commercialized, several underlying integrated technologies must also be developed: improved design for cylinders to handle higher pressures, additional exhaust heat utilization through improved turbo systems,85 improved thermal management (less heat rejection). and lower engine friction.

Emissions controls are the greatest barrier to the adoption of the direct injection diesel technology, especially with regard to NO, and particulate matter. As the fuel efficiency of diesel engines improves, NO, emissions also increase. To address this problem, three approaches are used: (1) in-cylinder process (combustion, air handling) to change the way the fuel is burned; (2) exhaust after-treatment to capture NO, and particulates; and (3) altered fuel properties to reduce sulfur, which shortens the life of a catalytic converter. Current research on exhaust aftertreatment includes particulate filters, NO, catalysts, and plasma systems. To date, a prototype particulate filter has been developed, small NO, catalysts have exceeded 50-percent reductions, non-thermal plasma devices have exceeded 70-percent reductions on a small scale, and engine efficiencies of approximately 52 percent have been achieved in test engines. In production engines, reductions of more than 50 percent for NO, and 80 percent for particulate matter have been achieved.

• Vehicle Design: In order to achieve the CCTI goals, it was assumed that fuel efficiency improvements of between 5 and 19 percent would be achieved through improvements in the design of heavy trucks. Several technologies are currently under investigation: reduced aerodynamic drag, reduced rolling resistance, and reduced losses related to auxiliaries and operating modes. To date, a research and development plan on heavy vehicle aerodynamic drag has been developed with industry, and a program has been started to compile data on the heating and cooling of the truck cab, with the goal of reducing idling time.

In the area of aerodynamic drag, the goal is to reduce drag coefficients from the current value of 0.60 to less than 0.50. Cab and trailer modifications must be cost-effective and must not hinder maintenance, payload, or the ability to meet government regulations and overall size restrictions. Current research is focusing on computational analysis tools for use in cab and trailer development. In the near term the trailer, which traditionally has received less attention than the cab, will be the focus. The main goal is to reduce the backdraft, or vacuum, at the end of a trailer that creates drag. Examples of work being done include curving the top of the trailer and creating a cone at the end; however, in the first case, haulers are unwilling to give up freight capacity to create a curved trailer. and in the second case the trailer may not meet safety regulations or may become a maintenance issue. Another. more promising example is the use of compressors to blow air into the vacuum, creating an airfoil. Similar types of work are being done on rolling resistance, such as the use of "super single" tires to replace the common twotire set.

Some of the major obstacles to rapid market penetration of these advanced technologies are ensuring that all State and Federal regulatory standards will be met, and ensuring that the return on investment will be realized within a short period of time.

85Energy Resources R&D Portfolio, Draft-2 (2/6/99), p. 204.

Results and Discussion

The heavy-duty truck technology characteristics in Tables 34 and 35 make up a representation of the technologies considered to meet the increased efficiency goal. These characteristics were used in the NEMS transportation freight truck model, which is economically price driven. The adoption of a technology, once introduced, is assumed to gain market share over time. It is also important to note that the trucking industry is very sensitive to fuel prices and demands a relativity short payback period. The fleet owners also place a high value on reliability, which will cause their technology adoption decisions to differ from decisions that would be made on economics alone.

Table 34. Heavy Truck Diesel Technology Characteristics in the Reference Case

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Source: Energy Information Administration, Assumptions for the Annual Energy Outlook 1999, web site www.eia.doe.gov.

Table 35. Heavy Truck Diesel Technology Characteristics in the CCTI Analysis Case

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In Tables 34 and 35, the date of commercial availability is the first year in which a technology has been or is expected to be offered by the manufacturers for possible purchase. Maximum potential market share is the highest percentage of trucks that could employ a given technology. Some technologies will never be utilized in certain vehicle applications regardless of cost. For example, garbage trucks probably will never be equipped with advanced drag reduction technologies.

In 2010, the stock fuel efficiency improvement in the CCTI case relative to the reference case is approximately 0.22 mpg, which results in a reduction of 128 trillion Btu of heavy truck diesel fuel use and a carbon emissions reduction of 2.4 million metric tons (Table 36). Reductions in both fuel use and carbon emissions amount to 0.4 percent of the total for the transportation sector. Two factors cause the projected reductions in fuel consumption and carbon emissions to be relatively small. First, because of their late commercial availability dates (Table 35), two of the most promising technologies, reduced rolling resistance and improved engine efficiency, are projected to have only limited market penetration by 2010 (Table 37). The second factor is the slow turnover rate for the stock of freight trucks. Even by 2020, the fuel economy of the truck stock is only 6.45 mpg in the CCTI case, compared with 5.78 mpg in the reference case (a 12-percent improvement). The difference has the effect of reducing heavy diesel fuel consumption from 4,554 trillion Btu in the reference case to 4,121 trillion Btu in the CCTI case, for a net fuel savings

of 433 trillion Btu and carbon emissions reductions of 8.6 million metric tons, or 1.2 percent of the total for the transportation sector.

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Source: Energy Information Administration, National Energy Modeling System runs CCTIB1.D033199H and CCT13.D0331998.

Table 37. Market Penetration of CCTI Proposal Technologies in the CCTI Analysis Case

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Source: Energy Information Administration, National Energy Modeling System runs CCTIB1.D033199H and CCTI3.D0331998.

Fuel efficiency in Table 36 refers to both the on-road stock average under real driving conditions and the new fuel efficiency average. With the CCTI new technology characteristics supplied by DOE's Office of Transportation Technologies, the fuel efficiency of new heavy trucks is projected to be 6.09 mpg in 2005 and 6.40 mpg in 2010.

Improved accessories has a larger market share than improved engine efficiency in 2010 because of its earlier availability date. By 2010, improved accessories will have been on the market for 12 years, whereas improved engine efficiency will have been available for only 4 years (Table 35). By 2020 the market share of improved engine efficiency technologies is projected to reach 86 percent of new sales and improved accessories 50 percent (Table 37).

Table 38 provides a summary of the fuel savings and carbon emissions reductions projected from implementing the CCTI light truck and heavy truck technology proposals simultaneously.

Table 38. Combined Effects of CCTI Light Truck and Heavy Truck Technology Initiatives, 2005, 2010, and 2020

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Source: Energy Information Administration, National Energy Modeling System runs CCTIB1.D033199H and CCTITAN.D0331998.

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