Lt Col Kathy Hithe, USAF

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Fuel Cells

• Lt Col Kathy Hithe, USAF
• 15 March 2005

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Agenda

• Fuel Cell Basics
• Chemistry of a Fuel Cell
• How a Fuel Cell Works
• History and the Hydrogen Fuel Initiative
• Types of Fuel Cells
• Benefits
• Challenges
• Applications
• Civilian
• Military
• Commercial Fuel Cells
• DoD Fuel Cell Initiatives and Programs

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Fuel Cell Basics
Heat
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Chemistry of a Fuel Cell

• Anode side2H2 gt 4H 4e-
• Cathode sideO2 4H 4e- gt 2H2O
• Net reaction2H2 O2 gt 2H2O

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How a Fuel Cell Works
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Fuel Cell History

• Invented 1839 by William Grove
• 1960s
• Apollo Program
• Limited Military Interest - US Army Battery
  Re-Chargers
• 1970s
• Space Shuttle
• Oil Embargo of 1973
• Automobile Industry Interest
• Home and Business Power Generation
• 1990s 2000s
• Develop and Market Buses for Mass Transit
• Military Applications Picked up Speed
• Consumer Goods
• 2003
• Hydrogen Fuel Initiative

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Hydrogen Fuel Initiative

• A simple chemical reaction between hydrogen and
  oxygen generates energy, which can be used to
  power a car, producing only water, not exhaust
  fumes. With a new national commitment, our
  scientists and engineers will overcome obstacles
  to taking these cars from laboratory to showroom
  so that the first car driven by a child born
  today could be powered by hydrogen, and
  pollution-free. Join me in this important
  innovation to make our air significantly cleaner,
  and our country much less dependent on foreign
  sources of energy.
• President Bush, State of the Union Address, 28
  January 2003

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Proton Exchange Membrane Fuel Cell

• Polymer electrolyte is a thin, permeable sheet
• Efficiency range 40 to 50
• Operating temperature is about 80 degrees C, 175
  degrees F
• Cell outputs range from 50 to 250 kW
• Primary use mobile ops, transportation

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Phosphoric Acid Fuel Cells

• Electrolyte is phosphoric acid
• Efficiency ranges from 40 to 80
• Operating temperature is between 150 to 200
  degrees C (300 to 400 degrees F)
• Existing cells have outputs up to 200 kW 11 MW
  units tested
• Broad choice of fuels
• Primary use Small stationary power generation

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Alkali Fuel Cells

• Operate on compressed hydrogen and oxygen
• Electrolyte is potassium hydroxide (chemically,
  KOH) in water
• Efficiency is approx 70
• Operating temperature is 150 to 200 degrees C or
  300 to 400 degrees F
• Cell output ranges from 300 W to 5 kW
• Primary use space
• Used in Apollo spacecraft to provide electricity
  and drinking water

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Molton Carbonate Fuel Cell

• Electrolyte is high-temp compounds of salt (like
  sodium or magnesium) carbonates (chemically, CO3)
• Efficiency range 60 to 80
• Operating temperature is about 650 degrees C
  (1,200 degrees F)
• Cell output ranges from 2 MW and potentially up
  to 100 MW
• Primary use Large stationary power generation

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Solid Oxide Fuel Cell

• Electrolyte is a hard, ceramic compound of metal
  (like calcium or zirconium) oxides
• Efficiency 60
• Operating temperatures are about 1,000 degrees C,
  or 1,800 degrees F)
• Cells output is up to 100 kW
• Reformer is not required to extract hydrogen from
  the fuel
• Can recycle waste heat to increase efficiency
• Applications Large stationary power generation

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Benefits

• Reliability
• High Efficiency
• Conversion Efficiency of up to 80
• Hydrogen Energy Content
• Low Operating Cost
• Constant Power Production
• Computer Grade Power
• Clean Emissions
• Quiet, Stealthy Operations

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Challenges

• The Hydrogen Problem
• Disposal of Used Fuel Cells
• Operation in Extreme Conditions
• Underwater Ops
• Battlefield Environment
• Chem/Bio Effects
• Extreme Weather
• Miniaturization
• Standardization
• Cost

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Civilian Applications

• Transportation
• Fleet-based Applications
• Buses and Mass Transit
• Inter-City Delivery Vehicles
• Automobiles
• Commercial Airplanes
• Boats
• Power Generation
• Homes, Offices and Factories
• Vending Machines
• Consumer Electronic Goods
• Laptop Computers
• Cell Phones
• Remote Locations and Islands

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Military Applications

• Transportation
• UAVs
• Long Endurance, High Altitude Applications
• Reconnaissance, Remote Sensing, and Early Warning
• Airborne Communications Relay System
• Satellites
• UUVs, Submarines, and Ships
• Hybrid Systems
• Supplemental Power for DD(X)
• Remote Base Power Generation
• Limited Access to Utility Grid
• Battery and Generator Replacements
• Flight Line Aerospace Ground Equipment
• Man-portable Ops Future Combat System
• Covert and Clandestine Ops Special Ops
• Unattended Ops
• Battlefield Ops
• Battery Recharger
• Central Power Generator

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Hybrid Systems

• Combine Fuel Cell with Batteries, Internal
  Combustion or Diesel Engine, Photovoltaic Cell,
  Nuclear Power
• 2-Stage Process
• Electrolysis
• Uses electricity to convert water to hydrogen and
  oxygen
• Hydrolysis (Fuel Cell)
• Combines hydrogen and oxygen to produce water and
  electricity

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Portable Fuel Cell Systems

• 50-Watt Fuel Cell
• 4.3 x 7.7 x 8 inches
• Weighs 6.5 pounds.
• Power of 12 batteries

• 100-Watt Fuel Cell
• 4.3 x 8 x 10 inches
• Weighs 8.3 pounds

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Fuel Cell Vehicles
Typical Fuel Cell Stack for an Automobile
Fuel Cell Bus Initiatives US Europe
GM Hy-Wire
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DoD Fuel Cell Program

• Phosphoric Acid Fuel Cell (PAFC) Demonstration
• Installed at 30 bases
• Objectives
• Demonstrate fuel cell capabilities in real world
  situations,
• Stimulate growth and economies of scale in the
  industry
• Determine the role of fuel cells in DoD's long
  term energy strategy
• Residential Fuel Cell Demonstration
• FY01 and FY02 Programs
• PEM fuel cells demonstrated at military bases
• Range from 1 to 20 kW
• First units installed in January 02
• Initially, 21 PEM fuel cells at nine military
  bases
• Today 30 bases participating

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Military Applications - Mobile
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Military Applications Personal Power
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Military Applications Portable Power Generation
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Military Programs - Naval
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Military Programs - Naval
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UAVs
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Miniaturization Efforts
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Believe it or Not
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• Questions