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DOE's FreedomCAR: Hurdles, Benchmarks for Progress, and Role in Energy Policy
Subcommittee on Oversight and Investigations
Dr. Vernon P. Roan Ph.D., P.E.
These
comments are presented as an addendum to the brief summary of relevant issues
from the NRC 7th PNGV Peer Review Report that I have submitted to the
Committee. I also refer the
Committee to the complete report for additional information. This addendum is
not based on any type of consensus from the PNGV Peer Review Committee but
represents my own observations and opinions. Since
no specific questions have been presented to me by the Committee on Energy and
Commerce, I will offer opinions which I think relate to the probable areas of
consideration by the Committee, namely: 1.
The appropriateness of emphasis on hydrogen and fuel cells for
transportation-related energy visions of the future. 2.
The viability of the proposed FreedomCAR program as an approach for
directing government-sponsored research and development in support of long-range
transportation energy goals. With
respect to the first area of consideration, the ultimate transition from fossil
fuels to hydrogen as the primary chemical fuel is essentially inevitable. Fossil fuels represent a finite resource which will become
increasingly more difficult and expensive to utilize. Further, it seems likely that other technologies competing
for limited fossil fuel supplies (especially petroleum) such as for textiles, plastics, medicines, etc., might achieve a higher priority than simply burning the fuel to produce heat. Hydrogen, on the other hand, can be produced without consuming fossil fuels through the electrolysis of water by using non-fossil primary energy to produce the electricity. The non-fossil primary energy sources include hydro, wind, solar, geothermal, tidal, and nuclear. The
downside of producing hydrogen through the electrolysis of water is that more
electrical energy goes into producing the hydrogen than will be available from
the hydrogen fuel. This fact
emphasizes the importance of utilizing the hydrogen in the most efficient manner
as a transportation fuel. The most
efficient manner currently known is to use the hydrogen in a fuel cell-powered
vehicle. It should be noted,
however, that while electricity is still being produced for the national power
grid using some fossil fuel power plants, it might conserve more fossil fuel and
produce fewer greenhouse gases to put the renewable energy-produced power into
the grid and take older power plants off-line.
Another potentially more efficient alternative could be to use the
renewable-energy-produced power to recharge batteries in electric vehicles. An
interesting and troubling likely outcome of the transition period where a
significant portion of the electricity to produce hydrogen might come from
fossil-fuel plants and/or where hydrogen is partially produced from
steam-reforming natural gas (as almost all hydrogen is produced today) is that
the consumption of fossil fuel per unit of fuel energy available for
transportation will likely increase. In
other words, there will probably be a period of time when we actually use more
fossil fuel in our efforts to transition from fossil fuels to hydrogen in
transportation systems. In
addition, since- hydrogen
must be produced in an energy loss process, the total electrical energy
consumption as we move towards a hydrogen economy is sure to increase
dramatically. For example, an
average American home uses around 1000 kWh of electricity per month.
If this home has two fuel cell cars operating on hydrogen, it will take
about an additional 1000 kWh of electricity to produce the hydrogen fuel for the
cars. The implication is that a
complete transition to electrolysis-produced hydrogen for transportation fuel
will roughly require doubling the residential electrical generation capacity. Thus,
the DOE vision of proceeding towards a hydrogen economy with fuel cells becoming
the preferred way to utilize the hydrogen for transportation certainly seems
appropriate but there will be troubling events along the way. The
second area of consideration involves the path and some of the related
priorities en route to the long-range vision.
The path and priorities are extremely important since, even under the
best of circumstances, there will likely be some very difficult issues.
Fossil fuels, which have been essentially free except for the costs of
extracting and processing them, will be replaced with hydrogen which must be
"produced." Millions of
megawatts of new, non-fossil, power generation plants will be needed to replace
older fossil fuel plants and to provide electrical power to produce the
hydrogen. This transition will take
decades and will involve huge amounts of capital expenditures. During this
lengthy transition period, it will become increasingly important to have an
orderly evolution of technologies which can contribute to more fuel-efficient
vehicles. It will also be important
to use the available fossil fuels in the most appropriate manner.
As an example of the appropriate use of fuels, consider natural gas.-4- Natural
gas is the cleanest burning and has the highest mass heating value of any fossil
fuel currently being consumed. It
is the primary heat source for many electrical power plants including virtually
all now under construction or in the planning stages.
It is also used as a motor fuel in spark ignition, compression ignition
(diesel), and gas turbine engines. In
addition, it is the feedstock for
many chemical processes including virtually all of the hydrogen currently being
produced. Each of these uses of
natural gas is related to transportation energy options.
Specifically, some of the ways that natural gas could be utilized for
transportation, are: 1.
Directly as a motor fuel for conventional cars. 2.
Directly as a motor fuel for spark ignition (SI) or compression ignition
(CI) hybrid vehicles. 3.
Directly as a fuel for hydrocarbon fuel cell-powered vehicles (utilizing
onboard fuel processors). 4.
Directly as a power plant fuel to produce electricity for recharging
electric vehicle batteries. 5.
Indirectly as a feedstock to produce transportation hydrogen fuel through
steam reforming. 6.
Indirectly as an electricity generation power plant fuel to produce
electricity which would then be used to produce transportation hydrogen fuel
through electrolysis of water. Adding
to the complexity is the fact that the hydrogen produced by methods 5 or 6 could
also be used in many ways for transportation purposes, including as a fuel
for-5- conventional vehicles, hybrid vehicles, or fuel cell vehicles. Interestingly, for the relatively near term, probably the most energy-efficient way to utilize the natural gas for transportation is directly as a fuel in CI hybrid vehicles. The least energy-efficient option is to use it to produce hydrogen by electrolysis and then to use the hydrogen in conventional vehicles. The successful development of enabling hydrocarbon fuel, fuel cell technologies could provide not only another energy-efficient alternative but also an alternative with extremely low emissions. However, once the hydrogen is produced (by any means), the most energy-efficient way to utilize it will be in hydrogen fuel cells. Similar
options obviously exist also for the most effective ways to utilize petroleum or
any other form of fossil fuel. The
options which are actually feasible will depend on many factors but certainly
including the successes in developing many enabling technologies.
Clearly, of high importance in technology development must be included
the following: 1.
Exhaust emission reduction at the source or through after-treatment for
fuel- efficient compression ignition (diesel) engines. 2.
The fuel processing and other issues associated with hydrocarbon fuel
cell systems that would have costs, performance, physical characteristics,
durability, etc., compatible with consumer cars and other transportation
systems. 3.
Clean and energy-efficient ways of producing hydrogen. 4.
A plan for developing a hydrogen infrastructure that would be compatible
with widespread distribution and use of hydrogen-powered vehicles.-6- 5.
Development of vehicle onboard hydrogen storage that will allow safe and
inexpensive onboard storage of sufficient hydrogen to provide an adequate
vehicle range. 6.
The resolution of costs, performance, and other issues to make the
hydrogen fuel cell truly a technology compatible with mass-produced, low cost
automotive applications. As a final note, it should be emphasized that even with a good plan for achieving large-scale hydrogen production and infrastructure, it will be exceedingly difficult and expensive to implement. As an example, an Argonne National Laboratory study (ANL/ESD/TM-140) concluded that capital costs for production facilities capable of producing 1.6 millions of barrels of gasoline-equivalent hydrogen fuel per day, could be $400 billion for production and $175 billion for distribution. Their study was based on a "high" market penetration of hydrogen-fueled vehicles by the year 2030. Another study by Directed Technologies, Inc. (DE-ACO2-94CE50389, July 1997) was more optimistic but was partially based on assumptions of unlimited availability of very inexpensive natural gas and unlimited availability of off-peak electricity at 1.5 cents per kWh. There are also the inevitable problems with siting and licensing of facilities, as well as the obvious safety concerns of distributing massive quantities of liquid (-423°F.) or high pressure (3000 to 5000 psi) hydrogen. There are, of course, many other issues to be considered including many that should be fostered by the government en route to the long-term vision of a hydrogen economy and an efficient transportation utilization of the hydrogen. However, it is felt that the ones mentioned above are among the more important. In summary, with respect to the proposed FreedomCAR plan, it appears that it is reasonably well considered and includes the necessary elements to guide and support the more critical technology developments in a fashion appropriate for the government. Since the duration will involve many years of activities and many potential pitfalls, progress should be reviewed regularly and programs and plans changed as deemed appropriate.
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