Fuel Cell Buses in US Transit Fleets

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Lessons learned following almost four years of operation of the five Van Hool/UTC Power fuel cell buses at AC Transit, CTTRANSIT, and SunLine include:

• The demonstrations focused on proving that fuel cell transit buses can function in standard revenue transit service. The Van Hool/UTC Power fuel cell buses continue to be in standard revenue service since early 2006.
• The fuel cell power system manufacturer iterated its design, components, and implementation to explore reliability improvements, and is implementing these improvements in its new products.
• The energy storage and amount of on-board hydrogen fuel storage selected for these demonstrations were not optimal. Energy storage was problematic because implementation was not optimized with the hybrid propulsion system, and manufacturing quality control and shipping requirements were lacking. Also, the amount of hydrogen onboard was more than needed. The next-generation bus will use lithium ion batteries and carry less hydrogen onboard. These changes will reduce the weight of the bus by 6,000 lbs. The next-generation bus will be only 2,000 lbs heavier than a standard diesel bus.
• Demonstration participants expended great effort to educate the public about hydrogen and fuel cell propulsion in the locations where fuel cell transit buses were deployed. Two of the three locations surveyed their passengers to enhance public awareness of the buses and to obtain public impressions. Occasionally, the buses were provided to other locations for public events.
• Hydrogen fuel production and dispensing infrastructure has worked well for the three locations. However, scaling up for larger demonstrations and “greening” hydrogen production and delivery will require additional research and testing.

Progress and Needs
In the next few years, the United States will progress through stage-one introduction of fuel cell transit buses. Planned demonstrations will continue to address the following areas:
• Bus performance—The purpose of step-one demonstrations of fuel cell transit buses is to prove reliability and begin assessing fuel cell power systems and related components for durability. Hybrid/fuel cell systems must also be optimized for reliability and durability. Newer/next-generation fuel cell buses are optimizing on-board hydrogen storage and packaging. Step one is nearing completion in North America with larger orders of fuel cell buses for the ZEBA and BC Transit demonstrations.
• Fueling stations and hydrogen source—Providing wider and better fuel availability and optimizing fueling station sizes for multiple vehicles requires more hydrogen fueling stations. Scaling of hydrogen fueling stations will also be needed as larger fleets of fuel cell buses are demonstrated. In addition, it is important to prove that fuel can be clean and “green” at the same time for hydrogen produced and delivered at dispensing stations.
• Preparation for market introduction—Demonstration of larger numbers of hydrogen fuel cell transit buses requires market preparation, including assessing the availability of technologies and products; training fleet personnel and the public; developing codes and standards; and continuing data collection, analysis, and reporting.
• Cost reduction—Considering their current high capital cost, a priority regarding fuel cell transit buses is cost reduction. Cost reduction sufficient to make fuel cell buses competitive in the marketplace must be validated. However, purchase price has little relevance if the buses cannot meet performance standards. After fuel cell bus designs have proven performance and durability, the industry can investigate ways to reduce the cost of the buses and replacement components. As with all developmental technologies, larger-quantity orders can help manufacturers develop low-cost manufacturing techniques. The industry also needs to investigate ways to lower operational costs.