Promising Transit Applications of Fuel Cells, Alternative Fuels and
their Applications

William P. Chernicoff

Aviva Brecher

Kevin Green

Volpe National Transportation Systems Center

Research and Special Programs Administration

U.S. Department of Transportation

Cambridge, Massachusetts

National Association of

Environmental Professionals

Annual Meeting

June, 2002

There are no clean vehicles\...only "cleaner" vehicles

Options should be examined in the context of total energy utilized from
well to wheels and environmental impact from cradle to grave

Context for Understanding Fuel Cells, New Technologies, and Success

-   Technologies

-   Issues

-   Paths to success

-   Timelines, policies, and economics

-   Are buses an ideal platform?

Why Buses

The Case for Fuel Cell and AFV Buses

-   Buses present a unique niche market that is highly suitable to take
    advantage of the FC and address the numerous challenges associated
    with a shift to a hydrogen economy

-   Offer an opportunity to replace 75,000 transit vehicles. A shift
    from some of the "dirtiest" vehicles to "cleanest"

-   Immediate and profound impact on congested urban centers and
    population

Environmental Concerns of Diesel ICE Buses

-   Cancer agents from emissions

-   Smog and ozone

-   Quality of life

-   Concentrated exactly where people are

-   ![](media/image1.wmf)Respiratory irritants

The figure shows emissions data from NYCT bus fleet.

Energy Demand

![](media/image3.wmf){width="4.916666666666667in" height="2.96875in"}Our
demand is only increasing while fuel economy is not.

![](media/image4.wmf)The figure shows U.S. Energy consumption by medium
and heavy-duty vehicles. Energy consumption has increased from 3
quadrillion BTU in 1970 to over 6 quadrillion BTU in 1997.

The figure shows energy intensity of automobiles and transit buses.
Transit bus fuel intensity has increased slightly from 80% of 1990
intensity in 1970 to 110% of 1990 intensity in 1997, while automobile
energy intensity has decreased from 150% of 1990 intensity in 1970 to
95% of 1990 intensity in 1997.

Bus Fuel Cost

-   Diesel accounts for approx. 5% of total annual operating cost of a
    transit bus

-   Gaseous fuel: large upfront capital cost. Potentially cheaper on a
    dge basis

-   Transit agencies are subsidized

What is a Fuel Cell?

-   Fuel cells make electricity directly from chemical reactions, like
    batteries, but:

    -   Are refueled like engines

    -   Don't need recharging

-   Spacecraft has used fuel cells since the 1960's

-   Fuel cells are quiet, efficient, and have very low emissions,
    however:

    -   Most use hydrogen for fuel (energy)

    -   Fuel processors (reformers) to convert gasoline and other fuels
        into hydrogen are still in development

    -   Fuel cells are still too costly for mass-produced vehicles

Schematic of a Fuel Cell

Proton Exchange Membrane (PEM) Fuel Cell

Single Membrane Electrode Assembly (MEA)

The figure shows a diagram of a fuel cell. Hydrogen gas enters at one
node and undergoes a chemical reaction (facilitated by a catalyst) with
oxygen at a membrane, forming and releasing water and oxygen gas.

PEM Fuel Cells

Today's Fuel Cells have higher power, are cheaper, and more compact.

![](media/image5.jpeg){width="2.75in" height="1.8215277777777779in"}

![](media/image6.jpeg){width="3.0in" height="2.192361111111111in"}

The pictures are photographs of fuel stacks and assemblies.

FTA Fuel Cell Buses

![](media/image7.jpeg){width="3.375in" height="1.7048611111111112in"}

The picture is a photograph of a 40 foot methanol fuel cell bus.

![](media/image8.jpeg){width="3.079861111111111in"
height="1.4493055555555556in"}

The picture is a photograph of a 30 foot fuel cell bus.

![](media/image9.png){width="1.3652777777777778in" height="2.0in"}The
picture is a photograph of a phosphoric acid FC engine.

Energy Solution

Thinking outside the wall

The key to the Fuel Cell's Value

Conventional Approach and Fuel Streams

Hydrocarbons \--\> Hydrogen via reformation or electrolysis \--\>
Renewables \--\> New Hydrogen Stream or Energy Storage

Advantages of the Bus as a Fuel Cell Platform

-   Well defined duty cycle

-   Centralized fueling and maintenance infrastructure

-   Dedicated maintenance staff

-   Trained operators

-   **Risk mitigation**

-   Size

-   Proximity to people

-   Performance improvement vs ICE

-   Can attract new "white collar" users

-   **Technology platforms can be applied to other medium and heavy duty
    vehicles**

Pathways to Success

Eliminating the "Chicken and Egg Complex"

-   Bridging Technologies-Myths and Realities

    -   Hybrid

    -   Natural Gas

    -   Other Fuels

-   Centralized vs. Decentralized Fueling Infrastructure

One chasm\...many bridges \--\> Buses address all of these issues.

Technical Challenges

-   On-board energy storage

    -   Fuel

    -   Electricity

-   Materials limitations of the fuel cell (Approx. 80% of Cost)

    -   Platinum

    -   Nafion ("remember this\...Plastics")

    -   FC sensitivity to impurities

        -   In the Fuel Stream

        -   From the Environment

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-   Limited life -- the disposal vehicle?

Zero Emissions?

-   Well-to-wheels (Hydrogen production can be energy-intensive)

-   But renewables are clean, right?

-   **Emissions displacement**

-   Does offer the potential

![](media/image10.wmf)

![](media/image37.wmf)

The figure shows estimated 2025 GHG emissions from light-duty vehicles
with exclusive gasoline use and 50% alternative fuel replacement:
internal-combustion fleet.

Technology Policy Options

For RC Buses and Vehicles

-   Decide the monetary value of having cleaner air and a reduction in
    petroleum consumption

-   Sensible financial incentives designed to achieve specific
    objectives and goals in conjunction with\...

-   Legislative action that promotes these objectives and goals

-   Support

    -   Basic R&D

    -   Demonstration programs

-   To date only partially effective

-   Need sustainable, long-term commitments and plans

In Conclusion

Buses using current alternative fuel and propulsion technology offer a
significant improvement to air quality, but are best justified as a
pathway to fuel cell propulsion.

While fuel cells offer the promise of "clean" transportation,
significant technological, economic, and policy hurdles remain.

Buses offer a good platform for initial technology deployment and
testing.

Timeframe: 5-10 years before initial non-prototype deployment.

For More Information:

William P. Chernicoff

Advanced Vehicle Technologies Division

Phone: (617) 494-2756

Fax: (617) 494-2961

Email: <chernicoff@volpe.dot.gov>

[http://www.volpe.dot.gov](http://www.volpe.dot.gov/)

Hybrid Propulsion

-   Platform for developing systems integration\...but only goes so far

-   Platform to use battery or other electrical charge devices

-   Exposure and experience with high voltage systems

-   Technology is beyond initial prototype

-   Can use much of the existing infrastructure

Hybrid vs. Conventional System

The figure shows a large IC engine and mechanical transmission.

The figure is a schematic of a hybrid propulsion system. It shows a
small IC engine generator electric drive motor and energy storage system
controller.

Natural Gas

-   Possibility of providing hydrogen backbone

-   Experience with high pressure gas

-   Some infrastructure compatibility with hydrogen

-   Immediate "interim" solution

-   Technology is mature

-   Already in use and deployed

-   Well developed Codes, Standards, and Best Practices

    -   Transfer knowledge and experience to hydrogen systems

Hydrogen Production Paths

-   Electrolysis

-   Hydrocarbon reformation

    -   On-board methanol

    -   On-board gasoline or diesel

    -   Off-board natural gas

-   Other