This report by the National Research Council’s (NRC’s) Committee on Review of the FreedomCAR and Fuel Research Program, Phase 3, is the third NRC review. The Phase 1 and Phase 2 reviews were issued in 2005 and 2008, respectively (NRC, 2005, 2008). The long-range goals of the Partnership focus on a transition to a highway transportation system that uses sustainable energy resources and reduces emissions, including net carbon emissions, on a life-cycle or well (source)-to-wheels basis (DOE, 2004). The Partnership focuses on precompetitive research and development (R&D) that can help to accelerate the emergence of technologies that can meet the long-range goals.
The transition is envisioned by the Partnership to begin with the internal combustion engine (ICE)-powered light-duty vehicles that, because R&D leads to a better understanding of the in-cylinder combustion process, achieve increased efficiency and decreased emissions. It would continue with R&D leading to improved hybrid vehicles, both conventional hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), while hydrogen and automotive fuel cell research also continues on the path leading to private-sector commercialization decisions by the year 2015. Increasing the capabilities of high-energy batteries for PHEVs could also lead to the market penetration of all-electric or battery electric vehicles (BEVs).
At the request of the U.S. Department of Energy (DOE), the committee issued an interim letter report (see Appendix B) in July 2009, about the time that the DOE fiscal year (FY) 2010 budget request to Congress essentially “zeroed out” the hydrogen and automotive fuel cell portions of the program in favor of developing nearer-term technologies. The letter report generally agreed with increased efforts on potentially nearer-term technologies in order to reduce petro-
leum dependence—efforts such as biofuels and the shifting of some transportation energy to the electrical grid (through the development of PHEVs and BEVs), but it expressed concern about effectively abandoning the longer-term hydrogen and automotive fuel cell programs. Given the uncertainty of technical and market success of many of the technologies under development, the committee believes that longer-term hydrogen and automotive fuel cell programs should remain in a balanced R&D portfolio of different options and is an appropriate strategy for the Partnership to pursue.
Since the DOE budget request for little or no funding (which was subsequently mostly reinstated by Congress) for hydrogen and automotive fuel cell R&D came after most of the accomplishments between Phases 2 and 3 of this study, this report focuses primarily on those accomplishments and on significant remaining barriers. Indeed, PHEVs, BEVs, and biofuels were not included in the initial FreedomCAR and Fuel Partnership program, so there were few such activities to evaluate or compare between Phases 2 and 3. The accomplishments were made possible, for the most part, by funding from the DOE, matching contributions from the DOE contractors, and efforts by the light-duty-vehicle original equipment manufacturers (OEMs)—the automotive manufacturers and their suppliers. As had previously been true, considerable guidance for needed research was provided by joint industry/government technical teams. This structure has been demonstrated to be an effective means of identifying high-priority, long-term precompetitive research needs while also addressing societal needs such as reducing petroleum dependence and greenhouse gas production. However, there are several very substantial barriers remaining that could inhibit positive fuel cell vehicle commercialization decisions by 2015.
Even though there had been considerable emphasis on hydrogen fuel and automotive fuel cells, there are a number of technical areas where R&D as well as technology validation programs have been pursued, including the following (see Chapter 3):
ICEs potentially operating on conventional and various alternative fuels,
Automotive and non-automotive fuel cell power systems,
Hydrogen storage (especially onboard vehicles) systems,
Electrochemical energy storage,
Electric propulsion systems,
Hydrogen production and delivery, and
Materials leading to vehicle weight reductions.
In each of these technology areas, there are specific research goals (targets) established by the Partnership for 2010 and 2015. Program oversight is provided by an Executive Steering Group consisting of the DOE Assistant Secretary for Energy Efficiency and Renewable Energy (EERE) and a vice-presidential-level executive from each of the Partnership companies. The DOE EERE efforts are
divided between the Vehicle Technologies (VT) program and the Hydrogen, Fuel Cells and Infrastructure Technologies program (HFCIT; the latter has been renamed the Fuel Cell Technologies [FCT] program). The Partnership collaborates with other DOE offices outside of EERE—for example, Fossil Energy, Nuclear Energy, Electricity Delivery and Reliability, and Science—as well as within EERE, such as the Biomass program, which are not part of the Partnership. The U.S. Department of Transportation (DOT) is also involved in safety-related activities as well as existing or new hydrogen (or other fuels) pipelines and delivery trucks, including those for hydrogen and biofuels.
The scope of this review, as for the previous reviews, is to assess the progress in each of the technical areas, comment on the overall adequacy and balance, and make recommendations, depending on issues identified by the committee, that will help the Partnership to meet its goals (see Chapter 1 for the committee’s full statement of task). This Summary provides overall comments and a brief discussion of the technical areas covered more completely in the report and presents the committee’s main conclusions and recommendations.1 Additional recommendations appear in appropriate topic areas of Chapters 2 through 4.
Since the creation of the FreedomCAR program in January 2002, it has undergone significant changes in Partnership members, with five energy companies added in September 2003 and two electrical power companies in 2008. Even though the technologies involved are not all under the FreedomCAR and Fuel Partnership umbrella, the potential pathways to the long-term objectives of reduced petroleum consumption as well as reduced criteria emissions and reduced greenhouse gases (GHGs) seem also to have broadened. In the collective opinion of the committee, there are essentially three primary alternative pathways:
Improved ICE vehicles coupled with greater use of biofuels,
A shifting of significant portions of transportation energy from petroleum to the grid through the expanded use of PHEVs and BEVs, and
The transition to hydrogen as a major transportation fuel utilized in fuel cell vehicles.
In general, the committee believes that the Partnership is effective in progressing toward its goals. There is evidence of solid progress in essentially all areas, even though substantial barriers remain (see Chapter 5).
Most of the remaining barriers relate to cost (e.g., fuel cells, batteries, etc.), although there are also substantial performance barriers (e.g., onboard hydrogen
storage, demonstrated fuel cell durability, adequate battery energy storage capability, etc.) and production and infrastructure barriers (e.g., the need for widespread affordable hydrogen if mass-produced fuel cell vehicles are to become a reality, a feedstock/production combination for biofuels that does not compete with food crops, etc.).
The fuel cell/hydrogen R&D is viewed by the committee as long-term, high-risk, high-payoff R&D that the committee considers not only to be appropriate, but also to be of the type that much of it probably would not get done without government support. Especially under the present economic conditions, the committee considers R&D for other precompetitive technologies, which could help reduce industry development times, also to be appropriate.
Advanced Internal Combustion Engines and Emission Controls
There seems to be little doubt that, regardless of the success of any of the pathways discussed, the ICE will be the dominant prime mover for light-duty vehicles for many years, probably decades. Thus, it is clearly important to perform R&D to provide a better understanding of the fundamental processes affecting engine efficiency and the production of undesirable emissions. Consequently, it is important to maintain an active ICE and liquid fuels R&D program at all levels, namely, in industry, government laboratories, and academia, to expand the knowledge base to enable the development of technologies that can reduce the fuel consumption of transportation systems powered by ICEs. This is the focus of the advanced combustion and emission control (ACEC) technical team.
All aspects of ICE operation are being pursued, and good progress is being made. Improvements have been achieved in ICE efficiency, including that for a hydrogen-fueled ICE, as well as advancements in different combustion regimes under investigation. With the projected increased use of biofuels, the technical team is now also engaged in fundamental combustion, emission, and kinetic studies of fuel derived from biomass. This work is aimed at understanding the fundamental changes that occur in ignition and emission-formation processes when different compounds, such as methyl esters that are found in biofuels, are used in the engine.
Recommendation 3-3. The advanced combustion and emission control technical team should engage with the biofuels research community to ensure that the biofuels research which the team is conducting is consistent with and leverages the latest developments in the field of biofuels R&D.
From the beginning of the FreedomCAR program, fuel cells have been a long-term focus. They, along with the hydrogen fuel that they would consume, offer the promise of zero emissions (produced directly by the vehicle2), high efficiency, and the smooth, quiet operation that goes with an electric propulsion system. With this focus, progress has been significant, with continuing increases in performance and decreases in projected costs essentially every year. However, in spite of the significant progress, no single fuel cell technology has attained the combination of performance and projected costs to be competitive with conventional systems.
With regard to the performance, planning, and management of fuel cell R&D, the committee’s assessment is that the fuel cell technical team is well coordinated and is aligned with respect to the achievement of the goals and the longer-term, high-risk technology challenges, especially as the automotive OEMs are now road testing prototype fuel cell vehicles. Most performance targets have been met in various demonstrations but not with a single technology.
Key achievements highlighted by the DOE and made since the previous review are primarily performance- and cost-related. Demonstrated stack lifetimes in on-road vehicles have increased from approximately 1,250 hours to 1,977 hours. With the goal of 5,000 hours, this change represents a significant achievement since the Phase 2 NRC review. Furthermore, single-cell and short-stack tests at the laboratory scale have demonstrated (using accelerated test protocols) much longer run times (3M Company, 7,200 hours) that meet or exceed the goals of the Partnership.
Two separate DOE-funded studies, with independent oversight, have concluded that at volumes of 500,000 units produced per year, the cost per kilowatt for the fuel cell subsystem, including the fuel cell and the balance of plant, will be approximately $60-$70/kW for an 80 kW unit. These figures are still more than two times higher than the target, but significantly lower than the $107/kW presented during the Phase 2 review (in 2008). The projected cost is split nearly evenly between the stack and the balance of plant.
The barriers that remain are both programmatic and technical. Programmatic issues relate to the coordination and execution of the high-risk research so that the solicitation timing and content address updated requirements of the Partnership. Technical barriers that still remain for the fuel cell stack are membrane and electrode life, in addition to cost. Both areas must remain the focus of the next round of solicitations.
Recommendation 3-7. The DOE should establish backup technology paths, in particular for stack operation modes and stack components, with the fuel cell technical team to address the case of current technology selections determined not likely to meet the targets. The DOE should assess which critical technology development efforts are not yielding sufficient progress and ensure that adequate levels of support for alternative pathways are in place.
Onboard Hydrogen Storage
Onboard hydrogen storage is a key enabler for fuel-cell-powered vehicles. The primary focus of the hydrogen storage program is to foster the development and demonstration of commercially viable hydrogen storage technologies for transportation and stationary applications. A specific goal of the program is a vehicle driving range of greater than 300 miles between refuelings while simultaneously meeting vehicle packaging, weight, cost, and performance requirements. The program also includes life-cycle issues, energy efficiencies, safety, and the environmental impact of the applied hydrogen storage technologies.
Most of the work of the onboard hydrogen storage program is organized in four centers of excellence (COEs): the Metal Hydrides COE, the Chemical Hydrogen Storage COE, the Hydrogen Sorption Materials COE, and the Hydrogen Storage Engineering COE. The hydrogen storage technical team provides input to the DOE that guides the work of the COEs.
The physical storage of hydrogen on vehicles as compressed gas (and to a lesser extent liquid hydrogen) has emerged as the technology path for the early introduction of fuel cell vehicles. The hydrogen storage capacity of tanks is performance limiting for some vehicle architectures and is expensive, but it will not prevent vehicle introduction into the market. The storage capacity of current high-pressure tanks does not meet the long-term program goals but may be adequate for some applications for which the cost can be justified.
Research aimed at significantly higher hydrogen storage capability needs to be maintained as a primary research focus. Materials-based storage at the level required to meet all program targets is considered theoretically achievable, yet no single material has been identified that simultaneously meets all of the targets (weight, volume, efficiency, cost, packaging, safety, refueling ability, etc.). The discovery and development of materials for effective onboard hydrogen storage is high-technical-risk R&D not likely to be accomplished without continued research attention and government funding.
Recommendation 3-12. The hydrogen storage program is one of the most critical parts of the hydrogen/fuel cell vehicle part of the FreedomCAR and Fuel Partnership—both for physical (compressed gas) and for materials storage. It should continue to be funded, especially the systems-level work in the Hydrogen
Storage Engineering COE. Efforts should also be directed to compressed-gas storage to help achieve weight and cost reduction while maintaining safety.
Recommendation 3-15. The search for suitable onboard hydrogen storage materials has been broadly based, and significant progress is reported. Nonetheless the current materials are not close to the long-range goals of the Partnership. Onboard hydrogen storage R&D risks losing out to near-term applications for future emphasis and funding. The management of a long-term/short-term joint portfolio should be given consideration.
Electrochemical Energy Storage
Improved electrochemical energy storage technologies, especially batteries and ultracapacitors, are critical to the advancement of both the Partnership’s nearer-term and long-term goals: significant improvement in their performance can result in greater electrification of vehicles (e.g., PHEVs and BEVs). These technologies have taken on even greater importance in the past year due to the priorities of the new administration seeking to achieve 1 million PHEVs on the road by 2015. The Partnership’s budget for electrochemical energy technologies has increased as the importance of PHEV battery development has increased. At present, about 75 percent of the funding is focused on near- and midterm development efforts directed at HEV and PHEV applications, and only 25 percent is directed to long-term R&D. The Partnership should also take the initiative to strengthen its focus on longer-term research on high-energy batteries and the establishment of a path toward BEVs.
Lithium-ion (Li-ion) battery technologies hold promise of achieving the long-term goals of high power, energy, and other performance requirements for HEV and PHEV applications at anticipated costs lower than those for other battery systems. Thus, the Partnership is correctly focused on the development of these technologies while it continues to benchmark competing battery technologies and encourages research on higher-energy chemistries for BEV applications. At present, none of the Li-ion battery chemistries meets the combination of performance, life, and cost goals for 2012 PHEV requirements. Although significant progress has been recorded in the Li-ion battery performance, durability, and safety, there has been no significant reduction in the projected cost of batteries. The system battery cost for a production of 100,000 units per year for the HEV application remains at more than $900, almost twice the 2010 target of $500. Battery cost will play an even bigger role in the eventual success of the PHEV and BEV applications because much larger batteries are required.
Recommendation 3-17. The Partnership should significantly intensify its efforts to develop improved materials and systems for high-energy batteries for both plug-in electric vehicles and battery electric vehicles.
Recommendation 3-18. The Partnership should conduct a study to determine the cost of recycling batteries and the potential of savings from recycled materials. A research program on improved processes for recycling advanced batteries should be initiated in order to reduce the cost of the processes and recover useful materials and to reduce potentially hazardous toxic waste and, if necessary, to explore and develop new processes that preserve and recycle a much larger portion of the battery values.
Electric Propulsion and Electrical Systems
Electric propulsion is needed for HEVs, PHEVs, fuel cell vehicles (FCVs), and BEVs. In all of these cases the systems used can be distinguished by the size and power required as well as by the architecture. In addition to the prime mover (engine, fuel cell, or battery), the essential elements of the electric propulsion system are power electronics and one or two electrical machines. The power electronics converts the direct current provided by the fuel cell, the engine-driven generator, or the battery into an alternating current to power motors and wheels. The Partnership has appropriately focused on key technical areas that are precompetitive, with the objective of long-term reductions in size (volume and weight) and cost. To accomplish this, emphasis has been on better packaging, cooling, materials, and devices.
To achieve better performance while operating power electronics at higher temperatures, materials and new designs are being incorporated into devices to replace currently used materials. For example, silicon carbide (SiC) devices are being investigated, including approaches to reducing their costs. SiC can potentially permit much higher power density because devices can operate up to much higher temperatures. Higher power densities mean more compact devices, thus less materials and potentially lower cost, and the Partnership is investigating a new process for making SiC on silicon (Si) substrates. Building these devices on Si is a desirable first step.
In all of the electric drive vehicle configurations, at least one electric motor provides the power to drive the wheels, but in some cases an electrical generator is also needed. The machines are basically of two types—permanent magnet brushless motors and induction motors—and each has advantages and disadvantages. Permanent magnet motors are currently used in essentially all electric and hybrid vehicles (the only exception being the Tesla Roadster) because of their high efficiency. However, the materials utilized come from only a few places on Earth and are relatively expensive. Induction motors, by contrast, use common materials, are used widely in industrial applications, cost less, and could be advantageous if the costs of batteries decline enough so that the premium on motor efficiency becomes less important than motor cost.
Onboard battery charging during regenerative braking affects the efficiency and cost of the motor. As new battery and motor materials are developed, use of
the Powertrain Systems Analysis Toolkit developed at the Argonne National Laboratory under DOE sponsorship may help quantify material cost and performance trade-offs between motor efficiencies and battery-charging requirements.
Recommendation 3-20. The Partnership should conduct a project to evaluate the effect of battery charging on lithium-ion battery packs as a function of the cell chemistries, cell geometries, and configurations in the pack; battery string voltages; and numbers of parallel strings. A standardized method for these evaluations should be developed to ensure the safety of battery packs during vehicle operation as well as during plug-in charging.
Recommendation 3-21. The Partnership should consider conducting a project to investigate induction motors as replacements for the permanent magnet motors now almost universally used for electric propulsion.
The challenge to the materials technical team is to generate a cost-neutral 50 percent vehicle weight reduction. The 50 percent weight reduction is critical to reaching FreedomCAR goals for energy consumption and emissions. However, the target of no cost penalty for such a large weight reduction was unrealistic when set, and it remains unrealistic. A similar conclusion was stated in the Phase 2 report. What is missing at this juncture is a projection of what the cost penalty will likely be.
The target for a project on magnesium power-train components was to replace aluminum components with magnesium for a minimum weight savings of 15 percent and a cost penalty of less than $2.00 for each pound saved. This project was completed and exceeded the weight savings goal with a cost penalty of $3.00/lb at current magnesium prices. Although over the cost target, the outcome was judged as demonstrating that magnesium was both technically feasible and potentially cost-effective in these applications.
Cost has been a limiting factor in the use of commercial carbon-fiber-reinforced polymers for the design of automotive structures and body panels. As a result of one of the projects, it appears that major cost savings could be achieved through the use of polyolefin for the feedstock in many carbon fibers. The recycling of carbon-reinforced composites could also aid in the adoption of such materials while possibly helping to reduce costs.
Recommendation 3-22. The materials technical team should develop a systems-analysis methodology to determine the currently most cost-effective way for achieving a 50 percent weight reduction for hybrid and fuel cell vehicles. The materials team needs to evaluate how the cost penalty changes as a function of the percent weight reduction, assuming that the most effective mix of materials is
used at each step in the weight-reduction process. The analysis should be updated on a regular basis as the cost structures change as a result of process research breakthroughs and commercial developments.
Recommendation 3-24. Methods for the recycling of carbon-reinforced composites need to be developed.
Hydrogen and Other Fuel/Vehicle Pathways
The Partnership in DOE’s Office of Energy Efficiency and Renewable Energy includes the hydrogen production, delivery, and dispensing program, which is, in turn, part of the Fuel Cell Technologies program, which is within the EERE. The Fuel Cell Technologies program addresses a variety of means of producing hydrogen in distributed and centralized plants using technologies that can be made available in the short, medium, and long term. Three fuel technical teams are addressing these issues: fuel pathway integration, hydrogen production, and hydrogen delivery.
The hydrogen fuel/vehicle pathway integration effort is charged with looking across the full hydrogen supply chain from well (source) to tank. Specifically, the goals of this integration effort are to (1) analyze issues associated with complete hydrogen production, distribution, and dispensing pathways; (2) provide input to the Partnership on goals for individual components; (3) provide input to the Partnership on needs and gaps in the hydrogen analysis program including the important industrial perspective; and (4) foster full transparency in all analyses, including an independent assessment of information and analyses from other technical teams.
The DOE continues to make important progress toward understanding and preparing for the transition to hydrogen fuel. In the continuing source-to-wheels analyses, seven pathways, including both distributed and centralized hydrogen production, have been assessed, and the key drivers for pathway costs, energy use, and emissions have been identified.
Technology is available to produce and distribute hydrogen commercially, but it is not yet completely optimized or cost-effective for supplying local fueling stations. Research efforts are focused on (1) the further development of options that reduce cost, (2) reducing dependence on imported petroleum and natural gas, and (3) reducing greenhouse emissions.
As indicated above, this effort has thus far been focused on hydrogen. However, the Partnership is now examining three power system approaches, only one of which involves hydrogen: fuel cells powered by hydrogen, advanced combustion engines powered by biofuels, and PHEVs and BEVs powered by electricity. Clearly, additional effort is needed to develop meaningful comparisons of the fuel implications of these three approaches.
Recommendation 4-1. The DOE should broaden the role of the fuel pathways integration technical team (FPITT) to include an investigation of the pathways to provide energy for all three approaches currently included in the Partnership. This broader role could include not only the current technical subgroups for hydrogen, but also subgroups on biofuels utilization in advanced internal combustion engines and electricity generation requirements for PHEVs and BEVs, with appropriate industrial representation on each. The role of the parent FPITT would be to integrate the efforts of these subgroups and to provide an overall perspective of the issues associated with providing the required energy in a variety of scenarios that meet future personal transportation needs.
The hydrogen production program embodies hydrogen generation from a wide range of energy sources including natural gas, coal, biological systems, nuclear heat, wind, solar heat, and grid-based electricity; grid-based electricity employs several of these sources to varying extents, depending on geographical area. In the short term, when a hydrogen pipeline system is not in place, distributed generation in relatively small plants will be required to supplement hydrogen available from existing, large-scale commercial plants. As the fleet of fuel-cell-powered cars grows and hydrogen demand increases, centralized hydrogen-generation plants with pipeline distribution will become increasingly attractive, and these are expected to replace most distributed generation eventually.
Approaches to hydrogen generation using thermal processes include coal and biomass gasification, bio-derived fuels reforming, and thermochemical splitting of water. The DOE had a program, completed in 2009, to improve natural gas reforming. This program established the feasibility of distributed generation at fueling stations using reforming and directionally improved gas cleanup technologies for centralized plants. Commercial options now exist to generate hydrogen either in distributed or centralized plants using natural gas.
The production of hydrogen from coal or from biomass feedstocks appears in the Hydrogen Production Roadmap as both a midterm technology (coal gasification with carbon sequestration) and a long-term technology (biomass gasification with carbon sequestration). The most critical challenges to the use of either feedstock are (1) the capital cost of the gasification processes and (2) the cost and availability of carbon sequestration.
Whereas distributed natural gas reforming has demonstrated the ability to meet the hydrogen cost targets of $2.00-$3.00 per gallon gasoline equivalent (gge) (based on the DOE standard set of assumptions), distributed ethanol reforming has not. The current cost estimates are higher than $4.00/gge, and the targets for 2014 and 2019 are $3.80/gge and $3.00/gge, respectively.
The DOE recognizes that water electrolysis may play an important role in the hydrogen infrastructure and is supporting numerous electrolysis efforts related to capital, electrocatalytic, and configuration/engineering. Some of the challenges with wind and solar-driven electrolysis approaches include efficient
power electronics for direct current (dc)-to-dc and alternating current (ac)-to-dc conversion; and controllers and communications protocols to match the source to the electrolyzer.
A significant factor in fuel cost and source-to-wheels efficiency for fuel-cell-powered vehicles is the means for delivering, storing, and dispensing hydrogen. In a fully developed hydrogen economy, the postproduction part of the supply system for high-pressure hydrogen will probably cost as much and consume as much energy as production does (NRC/NAE, 2004).
Progress has been made in all areas of the program. Delivery models have been developed that predict delivery and dispensing costs for different methods as a function of market penetration. In addition, hydrogen compression has been directionally advanced by investigating a centrifugal compressor design and also electrochemical compression.
Past funding for delivery and dispensing apparently has not been based on program needs but on budget constraints. Reducing the cost of delivery and dispensing from the current $2.00-$3.00/kg hydrogen to the 2017 target of less than $1.00/kg hydrogen will require substantial and consistent funding based on program needs. Otherwise, any chance of meeting the 2017 target will be forgone.
Recommendation 4-3. The Fuel Cell Technologies program should adjust its Technology Roadmap to account for the possibility that CO2 sequestration will not enable a midterm readiness for commercial hydrogen production from coal. It should also consider the consequences to the program of apparent large increases in U.S. natural gas reserves.
Recommendation 4-4. The EERE should continue to work closely with the Office of Fossil Energy to vigorously pursue advanced chemical and biological concepts for carbon disposal as a hedge against the inability of geological storage to deliver a publicly acceptable and cost-effective solution in a timely manner. The committee also notes that some of the technologies now being investigated might offer benefits in the small-scale capture and sequestration of carbon from distributed sources.
Recommendation 4-13. Hydrogen delivery, storage, and dispensing should be based on the program needed to achieve the cost goal for 2017. If it is not feasible to achieve that cost goal, emphasis should be placed on those areas that would most directly impact the 2015 decision regarding commercialization. In the view of the committee, pipeline, liquefaction, and compression programs are likely to have the greatest impact in the 2015 time frame. The cost target should be revised to be consistent with the program that is carried out.
Biofuels and the Partnership
Within the DOE, the Biomass Program has the responsibility for managing the development and progress for the bulk of the needs for biofuels, including biomass production, feedstock logistics, and biomass conversion to a biofuel. Historically the DOE focused on biofuel distribution and end use through the Partnership. This split of focus puts responsibility for making biofuels with the Biomass Program and the responsibility for delivering the biofuel and the light-duty-vehicle drive train with the Partnership.
A thorough systems analysis of the biofuel distribution and end-use system that accounts for engine technologies and petroleum blending fuel properties could help to identify priority areas for further development. This could result in modified priorities for different biomass sources, conversion processes, biofuels, distribution systems, and engines.
Recommendation 4-14. A thorough systems analysis of the complete biofuel distribution and end-use system should be done. This should include (1) an analysis of the fuel- and engine-efficiency gains possible through ICE technology development with likely particular biofuels or mixtures of biofuels and conventional petroleum fuels, and (2) a thorough analysis of the biofuel distribution system needed to deliver these possible fuels or mixtures to the end-use application.
DOE (U.S. Department of Energy). 2004. FreedomCAR and Vehicle Technologies Multi-Year Program Plan. Washington, D.C.: U.S. Department of Energy, Energy Efficiency and Renewable Energy. Available on the Web at <http://www.eere.energy.gov/vehiclesandfuels/resources/fcvt_mypp.shtml>.
NRC (National Research Council). 2005. Review of the Research Program of the FreedomCAR and Fuel Partnership, First Report. Washington, D.C.: The National Academies Press.
NRC. 2008. Review of the Research Program of the FreedomCAR and Fuel Partnership, Second Report. Washington, D.C.: The National Academies Press.
NRC/NAE (National Research Council/National Academy of Engineering). 2004. The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs. Washington, D.C.: The National Academies Press.