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Options for Alternative Fuels and Advanced Vehicles in Greensburg, Kansas
5/1/2008
After a devastating tornado that destroyed the town of Greensburg, Kansas in May 2007, plans were developed to rebuild the town as a sustainable community. This report focuses on outlining key success factors of infrastructure, alternative vehicles, and alternative and renewable fuels as part of an integrated energy strategy.
Authors: Harrow, G.
Life-Cycle Assessment of Energy and Greenhouse Gas Effects of Soybean-Derived Biodiesel and Renewable Fuels
3/1/2008
The life-cycle energy and greenhouse gas (GHG)emission impacts of three soybean-derived fuels were studied by expanding, updating, and using Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The fuels studied included biodiesel produced from soy oil transesterification; renewable diesel produced from hydrogenation of soy oil by using two processes (renewable diesel I and II); and renewable gasoline produced from catalytic cracking of soy oil. Four allocation approaches were used to address the co-products: a displacement approach; two allocation methods, one based on energy value and one based on market value; and a hybrid approach that integrates both the displacement and allocation methods. Each of the four allocation approaches generated different results and demonstrate the importance of the methods used in dealing with co-product issues for these renewable fuels.
Authors: Huo, H.; Wang, M.; Bloyd, C.; Putsche, V.
Validation of Hydrogen Fuel Cell Vehicle and Infrastructure Technology
10/1/2007
Hydrogen-powered fuel cell vehicles could play a central role in future transportation system. They produce only electricity, heat, and water at point of use. They could also use predominantly domestic--potentially renewable--energy supplies instead of imported oil for transportation.
Through a 2003 competitive solicitation, DOE selected four automobile manufacturer/energy company teams to participate in the project--Chevron/Hyundai-Kia, DaimlerChrysler/BP, Ford/BP, and GM/Shell. DOE is cost-share fundung those teams to build small fleets of fuel-cell vehicles plus fueling stations to demonstrate their use in five regions of the United States.
The U.S. DOE High Temperature Membrane Program
9/1/2007
Membranes used in current Proton Exchange Membrane (PEM) fuel cells require thermal and water management systems to control temperature and keep the membrane humidified. These components increase the weight and volume of the fuel cell system and add complexity. Estimates of the cost of the humidification systems for current membranes range from $5 to $8 per kW, while the thermal management system is estimated to cost $3 to $4 per kW. These costs must be reduced to meet the DOE transporation fuel cell system cost target of $30 per kW for the complete powertrain.
The cost and complexity of the thermal and water management systems could be minimized if the fuel cell operated at higher temperatures (up to 120 degrees C) and at lower relative humidity. Operation at 120 degrees C would also increase the tolerance of fuel cells to CO2, which would in turn reduce the cost of hydrogen from hydrocarbon sources because extraordinary steps would not be necessary to purify the hydrogen.
Authors: Kopasz, J.; Garland, N.; Manheim, A.
Clean Cities Annual Metrics Report 2006
7/1/2007
Clean Cities coordinators submit an annual report of their activities and accomplishments for the previous calendar year. Coordinators submit a range of data that characterize the membership, funding, projects, and activities of their coalitions as well as data about sales of alternative fuel blends, deployment of alternative fuel vehicles, hybrid electric vehicles, idle reduction initiatives, and fuel economy activities. NREL analyzes the data and translates them into gasoline reduction impacts.
Survey results indicate that about 375 million gallons of gasoline were displaced through Clean Citiew efforts in 2006, 50 percent more than in 2005. Alternative fuel vehicles accounted for 71 percent of the reduction. Biofuels (ethanol and biodiesel) used in AFVs displaced 128 million gallons, 34 percent of the total 375 million.
Authors: Bergeron, P.; Putsche, V.
SunLine Transit Agency Hydrogen-Powered Transit Buses: Preliminary Evaluation Results
2/1/2007
This preliminary report covers NREL's evaluation of hydrogen and fuel cell buses in service at SunLine Transit Agency in Thousand Palms, California. The report includes 11 months of performance data on two hydrogen-fueled buses: one fuel cell bus and one hybrid hydrogen-fueled internal combustion engine bus. The report also outlines the overall experience of the transit agency and its project partners in demonstrating these buses.
Authors: Chandler, K.; Eudy, L.
Alameda-Contra Costa Transit District (AC Transit)Fuel Cell Transit Buses: Preliminary Results
2/1/2007
This report includes preliminary evaluation results on three prototype fuel cell-powered transit buses operating at AC Transit in Oakland, California, since March 2006 and 6 baseline diesel buses that are similar in design to the fuel cell business. This report describes the equipment used and provides early experience details, lessons learned, and early experience details.
Authors: Chandler, K.; Eudy, L.
Performance of Automotive Fuel Cell Systems with Nanostructured Thin Film Catalysts
1/1/2007
Cost and durability are generally regarded as the major challenges to commercialization of fuel cells. Size, weight, and system complexity are also important barriers to adoption of fuel cells in light duty vehicles. In addition, thermal and water management for fuel cells are outstanding issues. Fuel cell operation at lower temperatures creates a small difference between the operating and ambient temperatures, necessitating large heat exchangers. Fuel and air feed streams need to be humidified for proper operation of fuel cells. In this paper, we evaluate the prospects of overcoming the barriers of cost, durability, weight, volume, thermal management, and water management by using nanostructured thin film catalysts (NTFCs) in membrane electrode assemblies (MEAs) In laboratory tests, the NSTF catalysts have shown significantly enhanced stability against surface area loss from Pt dissolution when compared to conventional Pt/C dispersed catalysts under both accelerated voltage cycling from 0.6 to 1.2 V and real-time start stop cycles. Also NSTF catalyst support-whiskers have shown total resistance to corrosion when held at potentials up to 1.5 V for 3 hours.
Authors: Ahluwalia, R.; Wang, X.; Lasher, S.; Sinha, J.; Yang, Y.; Sriramulu, S.
Santa Clara Valley Transportation Authority and San Mateo County Transit District Fuel Cell Transit Buses: Evaluation Results
11/1/2006
This report provides evaluation results of prototype fuel cell transit buses operating at Santa Clara Valley Transportation Authority (VTA) in San Jose, California. VTA has been operating three fuel cell transit buses in extra revenue service since February 28, 2005. The report includes 17 months of performance data on three 40-ft. Gillig buses with a fuel cell system by Ballard Power Systems. The report also outlines the overall experience for the transit agency and its project partners in demonstrating these zero-emission buses. The analysis in this report reflects the prototype status of these vehicles. There is no intent to consider the implementation of these fuel cell buses as commercial (or full revenue transit service. The evaluation focuses on documenting progress and opportunities for improving the vehicles, infrastructure, and procedures.
Authors: Chandler, K.; Eudy, L.
Designing New Transit Bus Garages to be Fuel Flexible
5/12/2006
The basic differences between the properties of gaseous and liquid fuels influence building design requirements for transit bus garages. Leaks, flammability range, and ignition temperatures must be considered when designing the structure, utilities, ventilation, and safety equipment.
Authors: Adams, R.
Transitioning to a Hydrogen Future: Learning from the Alternative Fuels Experience
2/1/2006
A wealth of practical knowledge concerning alternative fuel technologies, products, national policies, and market introduction exists within industry, regulated fleets, and voluntary programs. Issues relating to consumer choice, capital investment, business decision making, manufacturing, and infrastructure construction will need to be understood in the alternative fuels context if the hydrogen transition is to occur efficiently. The overall objective of this project is to assess relevant knowledge within the alternative fuels community and recommend transitional strategies and tactics that will further the hydrogen transition in the transportation sector and help avoid stranded assets in the alternative fuels industry.
Authors: Melendez, M.
Clean Cities Alternative Fuel Price Report - February 2006
2/1/2006
The Clean Cities Alternative Fuel Price Report provides regional alternative and conventional fuel prices for biodiesel, compressed natural gas, ethanol, hydrogen, propane, gasoline, and diesel. The Alternative Fuel Price Report is a snapshot in time of retail fuel prices.
Steam Reforming of Ethanol at Elevated Pressures for Distributed Hydrogen Production
1/1/2006
Ethanol is an attractive renewable fuel because, as a liquid fuel, it has a high energy density, it is easy to transport, and it is environmentally more benign than petroleum-derived fuels. The hydrogen produced by reforming needs to be purified and compressed to the appropriate storage and dispensing pressures. Compressing hydrogen is energy intensive and can consume a significant fraction of the fuel's heating value. A promising option for producing hydrogen from ethanol is by conducting the ethanol steam reforming reaction at an elevated pressure, since injecting liquid feeds (ethanol and water) into a pressurized reactor requires very little energy.
Authors: Lee, S.; Papadias, D.; Ahluwalia, R.; Ahmed, S.
