2009 National Hydrogen 

Association Conference

Keith Wipke, Sam Sprik, 

Jennifer Kurtz, Todd 

Ramsden1, John 

Garbak2

April 2, 2009

Columbia, SC

NREL/PR-560-45608

National Fuel Cell Vehicle Learning 

Demonstration Nears Full Deployment 

This presentation does not contain any proprietary, confidential, or otherwise restricted information

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

1

NREL, 

2

US Dept. of Energy
National Renewable Energy Laboratory 2 Innovation for Our Energy Future

Fuel Cell Vehicle Learning Demonstration 

Project Objectives and Targets

•Objectives

– Validate H2 FC Vehicles and Infrastructure in Parallel

– Identify Current Status and Evolution of the Technology

– Objectively Assess Progress Toward Technology Readiness 

– Provide Feedback to H2 Research and Development

Photo: NREL

Solar Electrolysis Station, Sacramento, CA

Performance Measure 2009 2015

Fuel Cell Stack Durability 2000 hours 5000 hours

Vehicle Range 250+ miles 300+ miles

Hydrogen Cost at Station $3/gge $2-3/gge

Key Targets
National Renewable Energy Laboratory 3 Innovation for Our Energy Future

Industry Partners: 4 Automaker/Energy-Supplier Teams;

Gen 2 Fleet Is Now Fully Deployed, Some Vehicles Retired

Gen 1 Gen 1

Gen 1 & 2

Gen 2

Gen 2 Gen 2

Gen 1

71

48

-

20 

40 

60 

80 

100 

120 

140 

160 

Cumulative Vehicles Deployed/Retired1

Vehicle Deployment by On-Board Hydrogen Storage Type

700 bar on-road

350 bar on-road

Liquid H2 on-road

700 bar retired

350 bar retired

Liquid H2 retired

Created Feb-23-2009 1:20 PM (1) Retired vehicles have left DOE fleet and are no longer providing data to NREL Created Feb-27-2009 9:10 AM

140

(1) Retired vehicles have left DOE fleet and are no longer providing data to NREL 

140
National Renewable Energy Laboratory 4 Innovation for Our Energy Future

0

5

10

15

20

25

30

35

Number of Vehicles

Total Vehicle Hours

Vehicle Hours: All OEMs, Gen 1 and Gen 2

In Service

Retired

Total Vehicle Hours = 85,244

Through 2008 Q4

Created: Mar-02-09 04:13 PM

DOE Learning Demo Fleet Has Surpassed 

85,000 Vehicle Hours and 1.9 Million Miles

0

5

10

15

20

25

30

35

40

Number of Vehicles

Total Vehicle Miles

Vehicle Miles: All OEMs Combined, Gen 1 and 2

In Service

Retired

Total Vehicle Miles Traveled = 1,924,869

Through 2008 Q4

Created: Mar-02-09 04:13 PM

Gen 2 vehicles make up most 

of 2nd bulge at low hours/miles

Some Gen 1 vehicles 

have now been retired 

(red bars)
National Renewable Energy Laboratory 5 Innovation for Our Energy Future

0

1

2

3

4

5

6

7

8

Delivered 

Compressed H2

Natural Gas On-site 

Reforming

Electrolysis Delivered Liquid H2

# of Stations

Production Technology

Infrastructure Hydrogen Production Methods 

Existing Stations

Retired Stations

Created Feb-26-09 10:09am

Majority of Project’s Fixed Infrastructure to Refuel 

Vehicles Has Been Installed – Examples of 4 Types

Stations added since June 2008:

Burbank, Long Beach, Ardsley, LAX-east

20 stations now deployed through Dec.

Delivered Liquid, 700 bar 

Irvine, CA

Mobile Refueler

Sacramento, CA

Steam Methane Reforming

Oakland, CA

Water Electrolysis

Santa Monica, CA

Total of 90,000 kg H2

produced or dispensed

0

5

10

15

20

25

Number of Stations

Reporting Period

Online Stations

Existing Stations

Retired Stations

Created Feb-26-09 10:09am

20
National Renewable Energy Laboratory 6 Innovation for Our Energy Future

Refueling Stations Test Performance in Various Climates; 

Learning Demo Stations Comprise ~1/3 of all U.S. Stations

Mar-18-2009

5

58

5

SF Bay Area DC to New York

7

Detroit Area

2

Orlando Area Los Angeles Area

17
National Renewable Energy Laboratory 7 Innovation for Our Energy Future

0 2 4 6 8 10 12 -30

-20

-10

0

10

20

30

40

50

60

1.1 % trips below 0 oC

Max Op = 140.0 o

F

Min Op = -2.2 oF

29.6 % trips above 28 o

C

Trip Frequency [%]

Temperature [

oC]

Average Ambient Trip Temperature: DOE Fleet

Created: Feb-26-09 5:56 PM

Distribution of Average Ambient Temperature

During Vehicle Operation

Expanded analysis of data shows 

normal distribution around 20 C
National Renewable Energy Laboratory 8 Innovation for Our Energy Future

60 Public Composite Data Products Have Been Published; 

New Results and Updates Every 6 Months

A subset of the 60 

latest results follow
National Renewable Energy Laboratory 9 Innovation for Our Energy Future

Dyno (1) Window-Sticker (2) On-Road (3)(4) 0

10

20

30

40

50

60

70

80

Fuel Economy (miles/kg H

2

)

Fuel Economy

 Gen 1

 Gen 2

Created: Mar-03-09 10:57 AM

(1) One data point for each make/model. Combined City/Hwy fuel economy per DRAFT SAE J2572.

(2) Adjusted combined City/Hwy fuel economy (0.78 x Hwy, 0.9 x City).

(3) Excludes trips < 1 mile. One data point for on-road fleet average of each make/model.

(4) Calculated from on-road fuel cell stack current or mass flow readings.

Ranges of Fuel Economy from Dynamometer 

and On-Road Data Similar for Gen 1 & 2
National Renewable Energy Laboratory 10 Innovation for Our Energy Future

Dyno Range (2) Window-Sticker Range (3) On-Road Range (4)(5) 0

50

100

150

200

250

300

Vehicle Range (miles)

Vehicle Range1

2015 Target

2009 Target

 Gen 1

 Gen 2

Created: Mar-03-09 10:56 AM

(1) Range is based on fuel economy and usable hydrogen on-board the vehicle. One data point for each make/model.

(2) Fuel economy from unadjusted combined City/Hwy per DRAFT SAE J2572.

(3) Fuel economy from EPA Adjusted combined City/Hwy (0.78 x Hwy, 0.9 x City).

(4) Excludes trips < 1 mile. One data point for on-road fleet average of each make/model.

(5) Fuel economy calculated from on-road fuel cell stack current or mass flow readings.

Driving Range for Gen 1 and Gen 2 Vehicles: 

Based on Fuel Economy and Usable H2

Gen 2 Vehicle Range Shows Significant 

Improvement from 700 bar Storage

250-mile 2008 

milestone met

Note: All Learning 

Demo Vehicles 

Based on Existing 

Platforms
National Renewable Energy Laboratory 11 Innovation for Our Energy Future

0 200 400 600 800 1000 1200 1400 1600 1800 2000 220

230

240

250

260

270

280

290

300

Op Hours

Voltage

Voltage vs. Operation Hours at 300A: Vehicle19-Stack1 871 847 900

288

259

0

0.2

0.4

0.6

0.8

1

Stack Weight Factors

Weight Value

Overall

DatQty

DatGap

DR1ciDR2ci

Created: Oct-09-08 3:01 PM

warm-up time=10 min

pwr rate filt=1000 kW/s

amp rate filt=1000 A/s

pts per fit=2500

1 data pt every 1seconds

2

2. FC Stack voltage decay estimate using 

robust, improved segmented linear fit

instead of linear fit (follows non-linear 

decay trends & early voltage decay)

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Vehicle12 Stack1

Vehicle15 Stack1

Vehicle17 Stack1

Vehicle19 Stack1

Vehicle16 Stack2

EcoCars

EcoCars: Stack OpHr Projections

Op Hrs

Stack

FleetWgtAve

OpTime

0 0.2 0.4 0.6 0.8

Vehicle12 Stack1

Vehicle15 Stack1

Vehicle17 Stack1

Vehicle19 Stack1

Vehicle16 Stack2

EcoCars: Stack Weights

Weight

Created: Oct-09-08 1:20 PM Stacks sorted by Stack Weight

3

Fleet

Stack

3. Fleet weighted average using FC Stack 

operating hour projections and weights 

(based on data and confidence in fit)

Improved Approach for Calculating Projected 

Time to 10% Voltage Drop for Stack and Fleet

1

1. FC Stack voltage & current polarization fit 

Note, 10% voltage drop is a DOE 

target/metric, not an indicator of end-of-life
National Renewable Energy Laboratory 12 Innovation for Our Energy Future

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2006 Target

2009 Target

Actual Operating Hours Accumulated To-Date Projected Hours to 10% Degradation

Max Hrs Accumulated (1)(2) Avg Hrs Accumulated (1)(3) Projection to 10% Degradation (4)(5)(6)

Time (Hours)

DOE Learning Demonstration Fuel Cell Stack Durability:

Based on Data Through 2008 Q4

Max Projection

Avg Projection

Created: Feb-24-09 1:21 PM

(1) Range bars created using one data point for each OEM. Some stacks have accumulated hours beyond 10% voltage degradation.

(2) Range (highest and lowest) of the maximum operating hours accumulated to-date of any OEM's individual stack in "real-world" operation.

(3) Range (highest and lowest) of the average operating hours accumulated to-date of all stacks in each OEM's fleet.

(4) Projection using on-road data -- degradation calculated at high stack current. This criterion is used for assessing progress against DOE targets,

 may differ from OEM's end-of-life criterion, and does not address "catastrophic" failure modes, such as membrane failure.

(5) Using one nominal projection per OEM: "Max Projection" = highest nominal projection, "Avg Projection" = average nominal projection.

 The shaded green bar represents an engineering judgment of the uncertainty on the "Avg Projection" due to data and methodology limitations. 

 Projections will change as additional data are accumulated.

(6) Projection method was modified beginning with 2008 Q2 data.

Gen 1 Stack Operating Hours and Projected Time to 

10% Voltage Drop

(DOE Milestone)

More data required to 

make Gen 2 projections 

(late 2009)

Some Gen 1 FC stacks 

have almost reached 2000 

hours without repair
National Renewable Energy Laboratory 13 Innovation for Our Energy Future

0

5

10

15

20

25

Operating Time [%]

Operating Time at Fuel Cell Stack Voltage Levels: DOE Fleet

<50%

50-55%

55-60%

60-65%

65-70%

70-75%

75-80%

80-85%

85-90%

90-95%

95-100%

>100%

% Max Fuel Cell Stack Voltage

All time

Time at low current

Created: Feb-26-09 5:56 PM

Stack Duty Cycle: Time Fuel Cell Spends at Various 

Voltage Levels Was Requested by FC Developers

~ Open-circuit 

voltage (~15% time)

~17% of time 

spent at <70% 

of max voltage
National Renewable Energy Laboratory 14 Innovation for Our Energy Future

0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 >8 0

5

10

15

20

25

30

35

Segmented Trips/Hour Histogram: DOE Fleet

Trips/Hour*

Frequency [%]

*Trips/Hour based on 50 hour segments

spanning stack operating period Created: Mar-09-09 9:46 AM

Fuel Cell Stack Trips Per Hour Histogram Provided 

as Input to FC Durability Protocol Task Force

~4 trips (starts) 

per hour is a 

representative 

average from 

our fleet data
National Renewable Energy Laboratory 15 Innovation for Our Energy Future

1

2

3

4

5

6

7

8

9

0-250 250-500 500-750 750-1000 1000-1250 1250-1500 1500-1750 1750-2000

Stack Op Hour Groups

Trips/Hour*

Statistics of Trips/Hour vs Operating Hour: DOE Fleet

*Trips/Hour based on 50 hour segments

spanning stack operating period

Data Range

25th & 75th Percentiles

Group Median

Outlier

Created: Mar-09-09 9:46 AM

Average Trips/Hour as a Function of Stack 

Operating Hour

Stacks that have 

demonstrated long 

hours show lower 

average trips/hour
National Renewable Energy Laboratory 16 Innovation for Our Energy Future

0

100

200

300

400

500

600

700

Specific Power (W/kg)

FC System Specific Power (W/kg)

2010 and 2015 DOE MYPP Target1 Gen 1

 Gen 2

Created: Sep-17-08 10:30 AM (1) Fuel cell system includes fuel cell stack and BOP but excludes H2 storage, power electronics, and electric drive.

Comparison of FC System Specific Power 

and Power Density Between Gen 1 to Gen 2

0

100

200

300

400

500

600

700

Power Density (W/L)

FC System Power Density (W/L)

2010 and 2015 DOE MYPP Target1 Gen 1

 Gen 2

Created: Sep-17-08 10:29 AM (1) Fuel cell system includes fuel cell stack and BOP but excludes H2 storage, power electronics, and electric drive.

Significant Improvements Seen in Specific 

Power (...systems getting lighter)

Power Density Did Not Improve Between 

Gen 1 and Gen 2 (...same size or larger)

Freeze Capability of Gen 2 Systems 

May Have Increased Volume
National Renewable Energy Laboratory 17 Innovation for Our Energy Future

5% 4%

34%

57%

Fuel Cell Vehicle Events (9357)

22%

5%

49%

24%

Fuel Cell Vehicle Labor (10216 hours)

Vehicle (non-powertrain)

Fuel Cell System

Powertrain

Battery

3%

11%

11%

14%

26%

36%

Fuel Cell System Events (3175)

< 1%

31%

24%

12%

13%

20%

Fuel Cell System Labor (5035 hours)

Thermal Management

Air System

Controls, Electronics, Sensors

Fuel System

Fuel Cell Stack

Other

Created: Mar-09-09 3:16 PM

Fuel Cell Vehicle Maintenance Events and Labor Hours

New Analysis of Vehicle Maintenance Data 

Highlights Areas for Improvement

FC system responsible for 

1/3 of maintenance events, 

which take 1/2 the time

Within FC system, stack is only the 5th

most (11%) frequent maintenance, but 

responsible for 1/3 of repair time

FC System

FC System

FC Stack

Non-powertrain responsible for 

>1/2 maintenance events
National Renewable Energy Laboratory 18 Innovation for Our Energy Future

14%

16%

17%

22%

By Number of Events

Total Number of Events = 1860

11%

19%

17%

22%

By Labor Hours

Total Hours = 9093

system control & safety

compressor

electrolyzer

reformer

dispenser

other

electrical

valves & piping

storage

Created: Mar-03-09 3:50 PM

Hydrogen Fueling Station Maintenance

Hydrogen Fueling Station Maintenance by System 

Shows ~Equal Responsibility of Major Components

Note that “system 

control and safety” 

cause more issues 

than the production 

components
National Renewable Energy Laboratory 19 Innovation for Our Energy Future

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

100

200

300

400

500

600

700

800

900

1000

1100

Avg Fuel Rate (kg/min)

Number of Fueling Events

Histogram of Fueling Rates

All Light Duty Through 2008Q4

5 minute fill of

5 kg at 350 bar

3 minute fill of

5 kg at 350 bar

16623 Events

Average = 0.78 kg/min

24% >1 kg/min

2006 MYPP Tech Val Milestone

2012 MYPP Tech Val Milestone

Created: Feb-25-09 5:24 PM

Actual Vehicle Refueling Rates from 16,000 

Events: Measured by Stations or by Vehicles

Average rate = 0.78 kg/min

24% of refueling events 

exceeded 1 kg/min

All Fills
National Renewable Energy Laboratory 20 Innovation for Our Energy Future

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

50

100

150

200

250

300

350

400

450

Avg Fuel Rate (kg/min)

Number of Fueling Events

Histogram of Fueling Rates

All Light Duty by Year Through 2008Q4

5 minute fill of

5 kg at 350 bar

3 minute fill of

5 kg at 350 bar

Year Avg (kg/min) %>1 

------- ----------------- -------

2005 0.66 16%

2006 0.74 21%

2007 0.81 26%

2008 0.78 24%

2005

2006

2007

2008

2006 MYPP Tech Val Milestone

2012 MYPP Tech Val Milestone

Created: Feb-25-09 5:24 PM

Refueling Rates by Year: Highest Number of 

Fills in 2008; ~1/4 Now Exceed 1 kg/min

Comparison 

by Year

2008

2007

2006

2005
National Renewable Energy Laboratory 21 Innovation for Our Energy Future

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

200

400

600

800

1000

1200

Avg Fuel Rate (kg/min)

Number of Fueling Events

Histogram of Fueling Rates

Comm vs Non-Comm Fills - All Light Duty Through 2008Q4

5 minute fill of

5 kg at 350 bar

3 minute fill of

5 kg at 350 bar

Fill Type Avg (kg/min) %>1 

------------- ------------------ -------

Comm 0.88 32%

Non-Comm 0.65 15%

Comm

Non-Comm

2006 MYPP Tech Val Milestone

2012 MYPP Tech Val Milestone

Created: Feb-25-09 4:26 PM

Non-Comm Has a 2nd

Peak at ~0.2 kg/min

Comm Fills Can

Achieve Higher

Fill Rates

Communication H2 Fills Achieving 35%

Higher Average Fill Rate than Non-Communication

Comm.

Non-Comm.

Comparison 

by Comm.
National Renewable Energy Laboratory 22 Innovation for Our Energy Future

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

200

400

600

800

1000

1200

1400

1600

1800

2000

Avg Fuel Rate (kg/min)

Number of Fueling Events

Histogram of Fueling Rates

350 vs 700bar Fills - All Light Duty Through 2008Q4

5 minute fill of

5 kg at 350 bar

3 minute fill of

5 kg at 350 bar

Fill Type Avg (kg/min) %>1 Count

------------- ------------------ ------- --------

350 bar 0.81 27% 14375

700 bar 0.59 3% 2033

350 bar

700 bar

2006 MYPP Tech Val Milestone

2012 MYPP Tech Val Milestone

Created: Mar-09-09 3:38 PM

Comparison of Fueling Rates for 

350 and 700 bar Pressure Fueling Events

700 bar fills are currently 27% 

slower than 350 bar fills

350 bar

700 bar

Comparison 

by Pressure
National Renewable Energy Laboratory 23 Innovation for Our Energy Future

On-Site Production Efficiency from Natural Gas 

Reformation and Electrolysis Compared to Targets

On-Site Natural Gas Reforming On-Site Electrolysis 0

10

20

30

40

50

60

70

80

2010 MYPP Target

2015 MYPP Target

2012 MYPP Target

2017 MYPP Target

Production Efficiency (LHV %)

Hydrogen Production Conversion Efficiency1

Average Station Efficiency

Quarterly Efficiency Data

Highest Quarterly Efficiency

Efficiency Probability Distribution2

Created: Feb-26-09 2:26 PM

1

Production conversion efficiency is defined as the energy of the hydrogen out of the process (on an LHV basis) divided by the sum of the energy into the production

process from the feedstock and all other energy as needed. Conversion efficiency does not include energy used for compression, storage, and dispensing.

2

The efficiency probability distribution represents the range and likelihood of hydrogen production conversion efficiency based on monthly conversion efficiency data

from the Learning Demonstration.

Electrolysis

Reformation
National Renewable Energy Laboratory 24 Innovation for Our Energy Future

0 10 20 30 40 50 60 70 80 90 100 0

10

20

30

40

50

60

70

Production Capacity Utilization1 [%]

Production Conversion Efficiency

2 [%]

Monthly Production Conversion Efficiency vs Utilization

Electrolysis Data

Electrolysis Fit3

Electrolysis Fit Confidence

Natural Gas Data

Natural Gas Fit3

Natural Gas Fit Confidence

Created: Mar-02-09 9:09 AM

1) 100% production utilization assumes operation 24 hrs a day, 7 days a week

2) Production conversion efficiency is defined as the energy of the hydrogen out of the process (on a LHV basis) divided by the sum of the energy into the production

process from the feedstock and all other energy as needed. Conversion efficiency does not include energy used for compression, storage, and dispensing.

3) High correlation with electrolysis data (R2

 = 0.87) & low correlation with natural gas data (R2 = 0.018)

On-Site Hydrogen Production Efficiency vs. 

Capacity Utilization

Many Learning Demonstration 

Stations Currently Have 

Excess Capacity; 

Higher Utilization Helps 

Efficiency

Electrolysis

Reformation
National Renewable Energy Laboratory 25 Innovation for Our Energy Future

Learning Demonstration Vehicle Greenhouse Gas Emissions 

Using Actual Production Efficiencies and Fuel Economies

0

100

200

300

400

500

600

700

WTW GHG Emissions (g CO2-eq/mi)

Learning Demonstration Fuel Cycle Well-to-Wheels Greenhouse Gas Emissions1

Baseline Conventional Mid-Size Passenger Car2

Baseline Conventional Mid-Size SUV2

Average WTW GHG Emissions (Learning Demo)

Minimum WTW GHG Emissions (Learning Demo)

WTW GHG Emissions (100% Renewable Electricity)

WTW GHG Probability Based on Learning Demo3

Created: Feb-26-09 11:32 AM

On-Site Natural Gas Reforming On-Site Electrolysis(4)

1. Well-to-Wheels greenhouse gas emissions based on DOE's GREET model, version 1.8b. Analysis uses default GREET values except for FCV fuel economy, hydrogen

production conversion efficiency, and electricity grid mix. Fuel economy values are the Gen 1 and Gen 2 window-sticker fuel economy data for all teams (as used in CDP #6);

conversion efficiency values are the production efficiency data used in CDP #13.

2. Baseline conventional passenger car and light duty truck GHG emissions are determined by GREET 1.8b, based on the EPA window-sticker fuel economy of a conventional

gasoline mid-size passenger car and mid-size SUV, respectively. The Learning Demonstration fleet includes both passenger cars and SUVs.

3. The Well-to-Wheels GHG probability distribution represents the range and likelihood of GHG emissions resulting from the hydrogen FCV fleet based on window-sticker fuel

economy data and monthly conversion efficiency data from the Learning Demonstration.

4. On-site electrolysis GHG emissions are based on the average mix of electricity production used by the Learning Demonstration production sites, which includes both

grid-based electricity and renewable on-site solar electricity. GHG emissions associated with on-site production of hydrogen from electrolysis are highly dependent on

electricity source. GHG emissions from a 100% renewable electricity mix would be zero, as shown. If electricity were supplied from the U.S. average grid mix, average GHG

emissions would be 1241 g/mile.

H2 FCVs Offer 

Significant Reduction 

of GHGs, even from 

Natural Gas Ref.

Electrolysis Reformation
National Renewable Energy Laboratory 26 Innovation for Our Energy Future

Summary

• Learning Demo evaluation is ~80% complete

– 140 vehicles and 20 stations deployed

– 1.9 million miles traveled, 90,000 kg H2 produced or dispensed

– 346,000 individual vehicle trips analyzed

– Project to continue through 2010

• Many new technical results since last NHA presentation

– All but 2 updated since last NHA

• H2 production efficiency, compressor efficiency, vehicle GHG emissions

• 350 vs. 700 bar refueling rates

• Several new FC stack usage statistics

• Ambient temperature distribution

• H2 fueling station maintenance by system

• Fuel cell vehicle maintenance by system

– All new results live on web site today 

• Roll-out of 2nd generation vehicles is now complete

• Station deployment nearing completion
National Renewable Energy Laboratory 27 Innovation for Our Energy Future

Questions and Discussion

Project Contact: Keith Wipke, National Renewable Energy Lab

303.275.4451 keith.wipke nrel.gov

All public Learning Demo and FC Bus Evaluation papers and presentations are available 

online at http://www.nrel.gov/hydrogen/proj_tech_validation.html

Systems Integration & Analysis

Basic Research & Applied R&D

DELIVERY

FUEL CELLS

STORAGE

PRODUCTION

Education

Market Transformation Market Transformation Market Transformation

Technology 

Validation

Safety, Codes & Standards

Manufacturing R&D

@