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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
• 2.8 Hydrogen
Overview
Hydrogen gas can be used in two
important ways within America’s
transportation sector. First, it can be
burned directly in a hydrogen internal
combustion engine (HICE) to power a
vehicle; and second, it can be combined
chemically with oxygen from the air
within a fuel cell to create an electric
current which can be used to power a
hydrogen fuel cell vehicle (HFCV).
HICEs can be used in a conventional
configuration or in hybrid configurations
(similar to today’s gasoline-electric
hybrids). A small number of vehicles
have also been built that can switch
between hydrogen and gasoline, and can
operate on gasoline as the need arises
due to the lack of a hydrogen fueling
infrastructure.
Hydrogen Fuel Cell Vehicles
2030 Benefits: Moderate-High:
• 40-55% reduction per vehicle
• 18% potential market penetration (LDV) is high
estimate from literature
2050 Benefits: High:
• 79-84% reduction per vehicle
• 60% potential market penetration (LDV) is high
estimate from literature
Net Included Costs: Net Savings to Moderate Cost: -
$160 to +$70 per tonne
• Some studies show much higher costs – range of -
$200 to +$800 from literature
Confidence in Estimates: Low
• Development of both vehicle technology and fuel
production/distribution infrastructure are highly
uncertain
Hydrogen fuel cells show potential for
transformative efficiency gains; vehicles
have been shown to operate with
on-road efficiencies of 40 to 70 percent,
i.e., 40 to 70 percent of the energy
contained in the fuel is put to useful
work (U.S. EPA, 2007; NREL, 2009b).
This is substantially higher than the 25 to
30 percent efficiency of most internal
combustion engines in use today.
Figure 2.2 provides recent test results
Key Cobenefits and Impacts: Mixed/Uncertain
• Current modeling shows decreases in some
pollutants but increases in PM; will depend upon
fuel source
Feasibility: Low-Moderate
• New distribution infrastructure required
Key Policy Options:
• R&D on fuel cell technology, hydrogen storage
technology, and hydrogen production technology
(including non-fossil energy sources)
showing the potential efficiency advantage of HFCVs compared to conventional gasoline
internal combustion engine (“Ref ICE”) as well as various HICE configurations
(conventional, split, and series hybrid). The focus of this report is on HFCVs.
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