. "7 Overall Conclusions and Recommendations." Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use. Washington, DC: The National Academies Press, 2010.
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Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use
TABLE 7-2 Relative Categories of GHG Emissions in 2005 and 2030 for Major Categories of Light-Duty-Vehicle Fuels and Technologies
Category of Aggregate CO2-eq Emission Estimates (g/VMT)
2005
2030
150–250
E85 herbaceous
E85 corn stover
E85 herbaceous
E85 corn stover
250–350
Hydrogen gaseous
E85 corn
Diesel with biodiesel
Hydrogen gaseous
CNG
350–500
E85 corn
Diesel with biodiesel
Grid-independent HEV
Grid-dependent HEV
Electric vehicle
CNG
Grid-independent HEV
SI conventional gasoline, RFG
Grid-dependent HEV
Electric vehicle
Low-sulfur diesel
E10 herbaceous, corn stover
SIDI conventional gasoline
E10 corn
SI tar sands
>600
Tar sands
500–599
Conventional gasoline and RFG
E10
Low-sulfur diesel
ABBREVIATIONS: CO2-eq, carbon dioxide equivalent; VMT, vehicle miles traveled; E85, ethanol 85% blend; E10, ethanol 10% blend; HEV, hybrid electric vehicle; CNG, com pressed natural gas; RFG, reformulated gasoline; SI, spark ignition; SIDI, spark ignition direct injection.
The tar-sands-based fuels have the highest GHG emissions of any of the fuels that the committee considered.
As shown in Figure 7-7, and in contrast to the damages analysis above, the operation of the vehicle is in most cases a substantial relative contributor to total life-cycle GHG emissions. That is not the case, however, with either the grid-dependent technologies (for example, electric or grid-dependent hybrid) or the hydrogen fuel-cell vehicles. In the latter vehicle technologies, the dominant contributor to life-cycle GHG emissions is electricity generation and the production of hydrogen rather than vehicle operation.
Heavy-Duty Vehicles
The committee also undertook a more limited analysis of the nonclimate-change-related damages and GHG emissions associated with heavy-duty vehicles. Although this analysis included operation, feedstock, and fuel com-
