|Full fuel cycle CO2 emissions for PHEV40s and FCVs with 2x (top) and 3x (bottom) baseline fuel economy, under different H2 production scenarios. Click to enlarge.|
The US Energy Information Administration (EIA) has published an analysis of the impacts on US energy import dependence and emission reductions resulting from the commercialization of advanced hydrogen and fuel cell technologies in the transportation and distributed generation markets.
Among its findings, the report concludes that successful deployment of hydrogen fuel cell vehicles (FCVs) is dependent on several concurrent R&D successes and investments within the next 25 years. At the same time, other promising technologies such as plug-in hybrid electric vehicles (PHEVs) offer opportunities for major reductions in petroleum use and CO2 emissions from light-duty vehicles (LDVs).
The development of a large market for hydrogen-powered light-duty fuel cell vehicles (FCVs) would likely require a major financial commitment by industry and government. The ultimate success of that market will depend on the ability to overcome significant technical and infrastructure challenges. Competition from other promising new vehicle technologies, such as plug-in hybrid electric vehicles (PHEVs) that could run on electricity from the grid for 50 to 80 percent of their travel, as well as continued improvement in more conventional technologies, make the prospect of widespread use of hydrogen FCVs an even greater challenge. Nonetheless, if the challenges can be met, FCVs powered with hydrogen can provide considerable reductions in light-duty vehicle (LDV) energy demand and carbon dioxide (CO2) emissions by 2050.
EIA produced the report, “The Impact of Increased Use of Hydrogen on Petroleum Consumption and Carbon Dioxide Emissions”, in response to a request by US Senator Byron Dorgan (D-ND), who is a strong Congressional supporter of hydrogen fuel cell technology.
To provide a comparison of the potential energy and CO2 emissions impacts of PHEVs and FCVs, EIA analyzed the impact of the successful development of a PHEV with a 40-mile electric range. EIA assumed that the PHEV would use gasoline in its engine, and achieve approximately 50 mpg in hybrid mode, and approximately 130 miles per gallon gasoline equivalent in all-electric mode. It also assumed that approximately 50% of annual PHEV travel will be in all-electric mode.
In neither the PHEV or the FCV cases is market penetration sufficient to make a significant energy impact by 2030. By 2050, however, projections of LDV energy use (at the point of use—i.e., the LDV fleet level—not primary energy use) indicate that PHEVs could provide energy reductions commensurate with those projected under similar FCV scenarios—and assuming a 3X fuel economy improvements on the FCV side.
In the PHEV scenario, total LDV energy demand is reduced by 5.4 quadrillion Btu (26.3 percent), as compared with 3.0 quadrillion Btu (14.8 percent) in the fuel cell with AEO2008 reference fuel economy scenario and 7.2 quadrillion Btu (35.3 percent) in the fuel cell with 3X fuel economy scenario. Although reductions in petroleum demand are projected across the scenarios, the PHEV scenario reduces petroleum demand by 38.0 percent (7.1 quadrillion Btu) relative to the reference case, while a 68.5-percent reduction (12.9 quadrillion Btu) is projected in the FCV scenarios. In the PHEV scenario, electricity demand in 2050 is increased by 2.5 quadrillion Btu compared to the reference case.
...Relative to the FCV scenarios that assume AEO2008 reference case fuel economy improvement, the PHEV scenarios project full fuel cycle CO2 emission reductions in 2050 that are similar to those achieved in the hydrogen production scenarios considered. In the PHEV scenario with AEO2008 reference case generation mix, total CO2 emissions are reduced by 165 million metric tons CO2 equivalent (8.5 percent) in comparison with the reference case in 2050... In comparison, the reductions projected in the FCV scenarios that assume the transition of hydrogen production to centralized natural gas SMR or coal with CCS, where CO2 emissions are 3.9 percent and 20.9 percent, respectively. If the generation mix projected in the S.2191 high cost scenario were achieved, CO2 emissions from PHEVs would be reduced by 30.9 percent (601 million metric tons CO2 equivalent relative to the reference case in 2050, comparable to the reductions projected in the most optimistic fuel cell scenarios with 2X fuel economy improvement.
...If fuel cell vehicles achieve 3X fuel economy improvement...then projected full fuel cycle CO2 emission reductions for all the hydrogen production scenarios exceed those projected in the PHEV scenario with the AEO2008 reference case utility mix. The projected emissions reductions for the PHEV scenario with the S.2191 high cost scenario utility mix exceed the reductions projected for the natural gas SMR FCV scenario.
While deployment of FCVs and a hydrogen infrastructure could results in considerable reductions in energy demand and full fuel cycle CO2 emissions, the report notes, the development of a large market for hydrogen-powered LDVs probably will require a massive financial commitment by industry and government and, ultimately, will hinge on success in fuel cell R&D. The key findings from this analysis are:
It is highly unlikely that hydrogen FCVs will have significant impacts on LDV energy use and CO2 emissions by 2030.
Depending on fuel economy improvement and rate of market penetration, hydrogen FCVs could reduce petroleum demand in 2050 by 37.1 to 84.1%.
Depending on the method of hydrogen production, full fuel cycle CO2 emissions in 2050 could be reduced by 2.0 to 63.8%, depending on the market penetration scenario.
Under similar market penetration assumptions, successful development of a PHEV-40 could provide significant reductions in petroleum use; however, the maximum reductions in petroleum use would be less than those projected in the most aggressive FCV scenarios.
The Impact of Increased Use of Hydrogen on Petroleum Consumption and Carbon Dioxide Emissions (SR/OIAF-CNEAF/2008-04)