Fuel Cell Electric Aircraft Energy Challenge New Era

Fuel Cell Electric Aircraft Energy Challenge New Era of Aviation James Dunn Advanced Technology Products Worcester, MA Electric Aircraft Symposium San Fran – May 2007

Fuel cells in Aviation § Electric UAV’s – Helios-NASA- Aerovironment § Auxiliary Power – Boeing APU – Madrid + § Electric Airships – HAA – Lockheed Martin § Electric Propulsion - Manned aircraft - E-Plane

Aerovironment “HELIOS” UAV Regenerative fuel cell system

High Altitude Airship Solar PV and Fuel Cells

Fuel Cell Powered Glider Electric Glider

Piloted Fuel Cell Aircraft 2 -place Electric Dyn. Aero

Benefits of Electric Aircraft § § § Increased Reliability – 1 moving part! Improved Safety QUIET - only propeller noise Improved Comfort and Easy Maintenance No Vibration Reduced life-cycle costs § NO EMISSIONS !

Why Fuel Cells § High Efficiency – 2. 5 X Gasoline Engines (60% vs. 23%) § Zero Emissions – Only Water Vapor No odors or fumes § Hydrogen Fuel – Sustainable and Renewable § High Energy Density – 300 - 600 WH/kg 2 -3 X battery density

The Energy Challenge ! § § § Airplane needs 25 k. W Power @ 100 mph 300 Mi. flight requires 75 k. Wh of Energy system Weight for 75 k. Wh: - Lead Acid Batteries = 3000 kg - Ni. MH Batteries = 1500 kg - Li. Ion Batteries = 600 kg Fuel Cell system (+ 3 kg H 2) = 165 kg (Gasoline Equivalent = 100 kg !)

The Challenge – Matching the energy density of Gasoline and IC Engines? Gasoline =13, 200 WH/kg @ 20% effic. Net = 2600 WH/kg Best Li. Ion Batts = 200 WH/kg Still a 13: 1 advantage for Gas!! (H 2 = 30, 000 WH/kg) Issues – Weight, Volume, HEAT, (+$$)

Hurdles & Issues § § § § System Weight – Power Density/Effic. Support Components – Power & Weight Hydrogen Storage/Generation System Heat Transfer methods & HEX System Safety Issues – FAA + Ongoing Customer Acceptance Costly Technology

Hydrogen Sources § § § § H 2 Gas - High Pressure Tank – 5000 psi Liquid Hydrogen – Cryo issues Reformed Gasoline – CO, CO 2 Methanol/Ethanol – Direct or reformate Ammonia (dissociated) – high yield Sodium borohydride – safe, costly Magnesium Hydride Other ? ?

NASA Fuel Cell Study Elements:

Selected Aircraft for Conversion § § § AGA Lafayette III All Carbon Kit - 28’ Wing We/Wo =. 31 80 hp. Rotax 912 < 12 k. W to Cruise Vne of 180+ kts

Aircraft Modeling for Hydrogen PEM Fuel Cell Motor Conversion NASA GRC MCR 01 ULM Kit Plane Airbreathing Systems Analysis Office (NASA GRC) Systems Analysis Branch (NASA La. RC)

MCR 01 ULM Fuel Cell Conversion Power Density Technology Sensitivity: PDPMAD = 1. 06 k. W/kg 800 MCR 01/Rotax 912 Advanced Technology > 800 nm Range Fuel Cell Stack Power Density: 2. 50 k. W/kg Electric Motor Power Density: 2. 30 k. W/kg PMAD Power Density: 1. 06 k. W/kg Range = 336 nm 2. 5 2. 3 2. 0 2. 3 1. 8 2. 1 PDStack (k. W/kg) 1. 7 1. 9 1. 5 1. 7 PDMotor (k. W/kg) 1. 5 1. 3 Applied State-of-the-Art Technology Further performance gains possible only if PMAD weight reduced! Fuel Cell Stack Power Density: 1. 57 k. W/kg Electric Motor Power Density: 1. 35 k. W/kg PMAD Power Density: 1. 06 k. W/kg is Range = 58 nm Gross weight constant at 992 lb limit

MCR 01 ULM Fuel Cell Conversion Power Density Technology Sensitivity: PDPMAD = 2. 60 k. W/kg Advanced Technology Fuel Cell Stack Power Density: 2. 50 k. W/kg Electric Motor Power Density: 2. 30 k. W/kg PMAD Power Density: 2. 60 k. W/kg Range = 644 nm 2. 5 2. 3 2. 1 1. 7 1. 9 1. 7 PDStack (k. W/kg) 1. 8 2. 0 2. 3 1. 5 1. 3 PDMotor (k. W/kg) Gross weight constant at 992 lb limit Diminishing returns on range – The heavy compressed hydrogen tank limits further gains.

Program Objectives § Demonstrate viability of Fuel Cell powered electric propelled aircraft § Determine the optimum energy source § Analyze performance parameters & range § Design/develop High efficiency H 2 PEM fuel cell § Integrate all components into Airframe and Test § Provide educational vehicle for students

Basic Schematic of Components

Students at Oshkosh

Energy Distribution

Battery + Fuel Cell System Rqmts. Max Power - Batteries + Fuel Cell 75 kw Bus voltage 270 DC Net Stack power - cont. 17 kw No. of Cells 180 Efficiency 60 % Fuel Cell sys. Wt. (w/sgl. H 2 tank) 80 kg Battery + Master Power Xtrol Wt. 50 kg Total Energy System Weight 130 kg

Fuel Cell System target weight § § § § § Stack (10 -18 k. W) Blower (Compressor)+ duct Misc. BOP, plumbing, sensors HEX System w/Radiators DC-DC Up-convertor Fuel Cell Controller/mon. Dynatech Tank/Reg. Mounting + Misc. TOTAL fuel Cell System Weight 25 kg 4 kg 9 kg 7 kg 5 kg 18 kg 5 kg 78 kg

New Lynntech Stack Design § Ultrahigh Efficiency (60%) § Light. Weight – Metal (No Graphite) Bipolar Plates § Ambient Air Ops No Compressor No Hydrators

10 k. W Fuel Cell Stack DESIGN SPECIFICATIONS § 180 cells § 300 cm 2 active area § Generation 3 endplates § 10. 25 k. W @ 16 psia § 137 V § 75 A § 50 ˚C § 25 kg (hydrated) § 400 W/kg (@ 250 m. A/cm 2) § 720 W/kg (@500 m. A/cm 2) 18 KW

Specific Energy Equivalent Total Fuel Cell System § Sgl. Tank - 78 kg System - 1 kg H 2 = 24 k. WH Net Energy Density = 24/78 = 307 WH/kg § Dbl. Tank – 96 kg system – 2 kg H 2 = 48 k. WH Net Energy Density = 48/96 = 500 WH/kg

Boeing Fuel Cell Glider Activities System Integration §System Lay – out Design • Motor and Drive • Battery Motor Controller Motor Fuel Cell Controller Electricity Liquid Coolant Control Hydrogen delivery/regulat ion “Throttle” Electric controlled propeller • Controllers and Converters • H 2 System Fuel Power Conditioner, Regulation, Battery charger Batteries • Fuel Cell Systems • Compressor • Heat exchanger • Pumps • Controller Legend Prop Control Outside Air Fuel Cell Stack Liquid to air heat exchanger Hydrogen storage

Boeing Activities Electrical Subsystem §Electrical Subsystem Configuration §Power Balance • Power Demand • Motor & Drive • Controllers • Converters • Power Generation • Fuel Cells • Battery • Ground Auxiliary Power

Safety and Flight Testing § Major concern on all new Aircraft § Pilot and Airframe issues

Safety and Flight Testing (Whoops – wrong button !)

Energy System Challenges § § § § Energy Density Thermal Management Recharge or Refuel Integration of Solar PV Cost Life Reliability

Technology Evolution § § § Area Motor/Xtrol Fuel Cell Sys. Fuel/H 2 Storage Energy Produced Range Today 2 kw/kg 7% H 2 – Wt. 200 WH/kg 150 k. WH 100 Mi Future (2020) 8 -10 kw/kg 5 -6 kw/kg 12 -15 % 5 -800 WH/kg 1000 k. WH 1000 mi.

Emerging Energy Solutions § Advanced Batteries – Lithium Ion + § High Density Ultra. Caps – EEStor – Other Nano. Structured Electrodes – 500 -2000 WH/kg § High Temp Fuel Cells – Higher power density § Advanced H 2 Storage – New mat’ls + tanks § New Energy Gen. Sources - Many

Future Technology Options § § § Airframe Weight reduction Improved Airframe/Propulsion Efficiency Energy/Fuel Storage options Higher Energy Density Storage Techs New Designs with integrated storage Improved Solar PV Design - Integration

Future Electric PAV ?

Carter. Copter Hi-Speed Electric Gyro. Copter