NREL is a national laboratory of the U.S. Department of Energy, Office of Energy 

Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Contract No. DE-AC36-08GO28308

Entering a New Stage of 

Learning from the U.S. Fuel Cell 

Electric Vehicle Demonstration 

Project 

Preprint 

Keith Wipke, Sam Sprik, Jennifer Kurtz

and Todd Ramsden 

National Renewable Energy Laboratory

John Garbak

United States Department of Energy

To be Presented at 25th World Battery, Hybrid and Fuel Cell 

Electric Vehicle Symposium & Exhibition

Shenzhen, China 

November 5-9, 2010

Conference Paper

NREL/CP-5600-49202

October 2010
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1 

Entering a New Stage of Learning from the U.S. Fuel Cell Electric Vehicle 

Demonstration Project

Keith Wipke1, Sam Sprik1, Jennifer Kurtz1, Todd Ramsden1, and John Garbak2

1

National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, CO 80401, USA

2

United States Department of Energy, 1000 Independence Ave, SW, Washington, DC, 20585, USA

E-mail: keith.wipke@nrel.gov 

Abstract—The National Fuel Cell Electric Vehicle Learning Demonstration is a U.S. Department of Energy (DOE) 

project that started in 2004. The purpose of this project is to conduct an integrated field validation that simultaneously 

examines the performance of fuel cell vehicles and the supporting hydrogen infrastructure. The DOE’s National 

Renewable Energy Laboratory (NREL) has now analyzed data from over five years of the seven-year project. During 

this time, over 144 fuel cell electric vehicles have been deployed, and 23 project refueling stations were placed in use. 

We have analyzed data from over 430,000 individual vehicle trips covering 2,500,000 miles traveled and over 130,000 

kg hydrogen produced or dispensed. During 2010, two of the four project teams will be concluding their involvement in 

the project, and the other two are continuing. Thus we will be able to focus our analysis efforts on a smaller number of 

vehicles and stations and enter into a new stage of learning for this project. This will allow us to dig deeper into the data 

to provide additional technical value to the two remaining teams as they improve their systems’ technical performance in 

preparation for pre-commercial launch of larger fleets of vehicles in California and New York. It will also give us an 

opportunity to gather data and analyze performance of improved vehicles compared to those that have been previously 

demonstrated, since these vehicles are one step closer to commercially available customer vehicles.

Keywords— fuel cell electric vehicle, demonstration, fuel cell degradation, hydrogen fueling infrastructure

1. Introduction

This paper discusses key results based on data through 

December 2009 from the U.S. Department of Energy’s 

(DOE’s) Controlled Hydrogen Fleet and Infrastructure 

Validation and Demonstration Project, also referred to as 

the National Fuel Cell Electric Vehicle (FCEV) Learning 

Demonstration. NREL has now analyzed data from over

five years of the seven-year project. During this time, 144 

vehicles were deployed, 23 project refueling stations were 

placed in use, and no fundamental safety barriers were

identified. We have analyzed data from over 436,000 

individual vehicle trips covering 2,500,000 miles traveled 

and over 130,000 kg hydrogen produced or dispensed. 

Key objectives of the project are to evaluate fuel cell 

durability, vehicle driving range, and on-site hydrogen 

production cost. This evaluation is performed through 

validating the use of FCEVs and hydrogen refueling 

infrastructure under real-world conditions using multiple 

sites, various climates, and a variety of hydrogen sources. 

Figure 1 shows photographs of the first- and secondgeneration vehicles and the structure of the industry teams 

providing NREL data. 

This report also marks a transition with the makeup of 

the industry participants who initiated the project in 2004. 

The project started with four automotive original 

equipment manufacturers (OEM) and energy partner 

teams. Since that time, DOE’s California Hydrogen 

Infrastructure Project executed by Air Products began 

providing data, and additional hydrogen fueling 

infrastructure is being installed in California under state 

and local funding that will also be providing data to 

NREL. We have also seen completion of the project for 

two of the four original OEM and energy partner teams, 

who provided their last data by early 2010. New 

analytical results generated after this report will need to be 

different, given the fact that there are only two automotive 

companies now providing data, and their sensitive data 

still need to be protected. Therefore, while this paper is 

not a final paper for the project, it is potentially the last 

paper to provide new commentary on the data involving 

all four automotive OEM teams up to December 2009. 

Previous comprehensive progress reports were published 

in July 2007 [1], November 2007 [2], and April 2008 [3], 

and another one will be published in August 2010. 

Figure 1: Photographs of the industry partners providing data to 

NREL on hydrogen fuel cell electric vehicles and fueling 

infrastructure (Photo credit: Keith Wipke)

Gen 1

Gen 2

Gen 2

Gen 1

(CHIP)

Gen 1 & 2

Gen 1 Gen 2

Daimler, BP GM, Shell

Chevron, 

UTC Power,

Hyundai-Kia

Air Products

Ford, BP
2 

Figure 2: Cumulative number of vehicles deployed, by hydrogen storage type and status

The three high-level objectives of this project are to 

validate hydrogen FCEVs and infrastructure against the 

following targets: 

• 250-mile range

• 2,000-hour fuel cell durability

• $3/gge hydrogen production cost (based on 

volume production). 

NREL works to provide the DOE and industry with 

maximum value from the data produced by this “learning 

demonstration.” We seek to understand the progress 

toward the technical targets, and provide that information 

to the Fuel Cell Technologies program research and 

development (R&D) activities. This information will 

allow the program to move more quickly toward costeffective, reliable hydrogen FCEVs and the supporting 

fueling infrastructure.

1.1 Approach

NREL’s approach to accomplishing the project’s 

objectives is structured around a highly collaborative 

relationship with each of the industry teams: 

Chevron/Hyundai-Kia, Daimler/BP, Ford/BP, GM/Shell, 

and Air Products. We are receiving raw technical data on 

both the hydrogen vehicles and the fueling infrastructure 

that allows us to perform unique and valuable analyses 

across all teams. Our primary objectives are to feed the 

current technical challenges and opportunities back into 

the DOE Fuel Cell Technologies Program and assess the 

current status and progress toward targets.

To protect the commercial value of these data for each 

company, we established the Hydrogen Secure Data 

Center (HSDC) at NREL to house the data and perform 

our analysis. To ensure value is fed back to the hydrogen 

community, we publish composite data products (CDPs) 

twice a year at technical conferences. These data products 

report on the progress of the technology and the project,

focusing on the most significant results. Additional CDPs 

are developed as additional trends and results of interest 

are identified. We also provide our detailed analytical 

results from each individual company’s data back to them 

to maximize the industry benefit from NREL’s analytical 

work and obtain feedback on our methodologies. These 

individual company results are not made available to the 

public.

In order to be able to evaluate such a large data set, 

NREL developed an in-house tool called the Fleet 

Analysis Toolkit (NRELFAT), which helped organize and 

automate the various analyses being performed on both the 

vehicles and the infrastructure. The tool has recently 

undergone a major rework to allow the analysis functions 

to be applied not only to FCEVs, but also to fuel cell 

buses, fuel cell forklifts, laboratory fuel cells, backup fuel 

cells, stationary fuel cells, and plug-in hybrid vehicles. 

The overall functionality of the NRELFAT has been 

covered in previous publications, so it will not be 

discussed in detail here. Having such a sophisticated tool 

in-house allowed us to rapidly respond to the DOE’s and 

the U.S. Department of Defense’s needs for evaluation of 

early market fuel cell applications.
3 

2. Demonstration Status

Industry teams were selected by DOE for this project in 

April 2004. The first data started flowing to NREL in 

September 2004 after DOE had signed cooperative 

agreements with the industry partners. Since that time 

data has been flowing continuously to NREL on a monthly 

or quarterly basis from the teams. The project was 

originally scheduled to be completed in September 2008, 

but was extended through September 2009. Two of the 

teams, Ford/BP and Chevron/Hyundai-Kia, completed 

their projects as scheduled in September 2009, while two 

other teams led by Daimler and GM continued beyond that 

time with a new scheduled completion date of September 

2011. Forty vehicles will be evaluated in the final portion 

of this project to track performance improvements from 

the latest technology. By the end of the project, it is 

anticipated that a cumulative total of 170 vehicles will 

have been evaluated.

This transition is reflected in some of the CDPs, which 

show the number and status of the FCEVs. As shown in 

Figure 2, there were a gradual number of vehicles retired 

through 2008 (approximately 20 vehicles), with a much 

larger number retired by the fourth quarter of 2009, when 

two teams completed their projects. Note that all of the 

first-generation vehicles utilizing 350-bar pressurized 

hydrogen storage or liquid hydrogen have been retired, 

and only 700-bar storage vehicles continue to operate. 

The cumulative number of fueling stations deployed 

through this project is 23. Of those 23, as of December 

2009, 8 have been decommissioned, 10 are continuing 

operation outside of the project, and 5 are continuing 

within the project. However, several of the 10 that are 

shown as continuing outside of the project are expected to 

be decommissioned in 2010. Stations demonstrated four 

major technologies: 1) onsite hydrogen through natural gas 

reformation, 2) onsite production through water 

electrolysis, 3) delivered liquid hydrogen, and 4) delivered 

compressed gas hydrogen. The highest number of stations 

used delivered compressed hydrogen, followed by on-site 

electrolysis. Over half of the electrolysis stations have 

been retired, whereas only one of the five on-site natural 

gas reformation stations has been retired.

While many of the project stations may come to the end 

of their useful demonstration life in the next few years, 

many new or upgraded stations are being opened in 

California as a result of the combined efforts of the 

California Air Resources Board, the California Energy 

Commission, and the South Coast Air Quality 

Management District. These new stations are helping 

provide a bridge from the early demonstration stations 

(from this project and other demonstrations) to a point in 

the future when the number of FCEVs is large enough to 

create a market pull for private sector investment.

In order to obtain a variety of data, the project included 

geographically diverse locations for demonstration of the 

vehicles and infrastructure. Initially, there were five 

regions of the country involved, including the San 

Francisco Bay area, the Los Angeles area, the Detroit area, 

Orlando, and a corridor from Washington, DC, to New 

York. In the last year, as two of the teams completed their 

portions of the project, some of the stations have been 

decommissioned, including all of the stations in Florida. 

As of August 2010, our database indicates that there are a 

total of 58 operational hydrogen fueling stations in the 

United States. 

3. Key Project Results Compared to 

Objectives

Key objectives of the project are to evaluate fuel cell 

durability, vehicle driving range, and on-site hydrogen 

production cost. Progress towards these objectives will be 

briefly highlighted in the following subsections. 

3.1 Fuel Cell Stack Durability

Many improvements have been made in NREL’s fuel 

cell durability analysis methodology, including using a 

two-segment linear fit and using a weighting algorithm to 

come up with a more robust and automatic fleet average. 

Now that the data submissions are complete on firstgeneration stacks (no new first-generation stack data is 

being received), we can make some final conclusions 

about that generation of technology. The maximum 

number of hours a first-generation stack accumulated 

without repair is 2,375, which is the longest stack 

durability from a light-duty FCEV in normal use published 

to date that we are aware of. On average, the slope of the 

initial power degradation is steeper in the first 200 hours 

and becomes more gradual after that (Figure 3). We also 

found that around 1,000 hours of data were required to 

reliably determine the slope of the more gradual secondary 

degradation. Finally, with significant drops in power 

observed at 1,900–2,000 hours, it appears as though this is 

a solid upper bound on first-generation stack durability 

(characterizing 2003–2005 technology). 

For second-generation fuel cell stacks (2005–2007 

technology), the range of maximum hours accumulated 

from the four teams is now approximately 800 to over 

1,200 hours (Figure 4), with the range of team average 

hours accumulated of approximately 300 to 1,100 hours. 

Relative to projected durability, the Spring 2010 results 

indicate that the highest average projected team time to 

10% voltage degradation for second-generation systems 

was 2,521 hours, with a multi-team average projection of 

1,062 hours. Therefore, the 2,000-hour target for durability 

has been validated. 
4 

30

40

50

60

70

80

90

100

110

120

130

 0 100 200 300 400 500 600 700 800 900 10001100120013001400150016001700180019002000

Stack Op Hour Segments(2)

% Power(1)

Max Fuel Cell Power Loss vs Op Hours: Gen1

1) Normalized by fleet median value at 200 hours.

2) Each segment point is median FC power (+-50 hrs).

 Box not drawn if fewer than 3 points in segment.

Gen1 Data Range

25th & 75th Percentiles

Group Median

Outlier

NREL CDP69

Created: Mar-23-10 10:39 AM

Gen1 Gen2 Gen1 Gen2 Gen1 Gen2 0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800

2006 Target

2009 Target

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

Time (Hours)

DOE Learning Demonstration Fuel Cell Stack Durability:

Based on Data Through 2009 Q2

Max Hrs Accumulated1,2 Avg Hrs Accumulated1,3 Projection to 10% Voltage Degradation4,5,6

Max Projection

Avg Projection

NREL CDP01

Created: Mar-23-10 10:39 AM

(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 projection bars 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 2009 Q2 data, includes an upper projection limit based on demonstrated op hours.

Figure 4: Hours accumulated and projected hours to 10% stack voltage degradation

Figure 3: Maximum fuel cell power degradation, Gen 1 stacks
5 

0 50 100 150 200 250 300 0

5

10

Percentage of Refuelings

Distance between refuelings [Miles]2

Distance Driven Between Refuelings: All OEMs

Gen1

Gen2

NREL CDP80

Created: Mar-23-10 10:53 AM

Total Refuelings1 = 25811

 Gen1

 Refuelings = 18941

 Median distance between refuelings = 56 Miles

 Gen2

 Refuelings = 6870

 Median distance between refuelings = 81 Miles

1. Some refueling events are not detected/reported due to data noise or incompleteness.

2. Distance driven between refuelings is indicative of driver behavior and does not represent the full range of the vehicle.

Figure 5: Actual miles between refuelings, comparing Gen 1 (green) with Gen 2 (orange)

3.2 Vehicle Driving Range

In FY 2008, the driving range of the project’s FCEVs 

was evaluated based on fuel economy from dynamometer 

testing (EPA adjusted) and on-board hydrogen storage 

amounts and compared to the 250-mile target. The 

resulting second-generation vehicle driving range was 

between 196 and 254 miles from the four teams and met 

the 250-mile range objective. In June 2009, an on-road 

driving range evaluation was performed by NREL in 

collaboration with Toyota and Savannah River National 

Laboratory. The results indicated a 431-mile on-road range 

was possible in southern California using Toyota’s FCHVadv fuel cell vehicle [4] (Table 1). 

Table 1: Toyota range analysis intermediate values and final 

results

Trip 

dist. 

(miles)

H2

used

(kg)

Remain

usable 

H2 (kg)

Calc.

remain 

range

(miles)

Total 

Range 

(miles)

Avg

Total 

Range 

(miles)

V1 331.50 4.826 1.4854 102.04 433.55 431 V2 331.45 4.875 1.4328 97.41 428.87

More recently, the significant on-road data that have 

been obtained from second- and first-generation vehicles 

allowed a comparison of the real-world driving ranges of 

all the vehicles in the project. The data show that there has 

been a 45% improvement in the median real-world driving 

range of second-generation vehicles (81 miles) as 

compared to first-generation (56 miles), based on actual 

distances driven between over 25,000 refueling events 

(Figure 5). Obviously the vehicles are capable of two to 

three times greater range than this, but the median distance 

travelled between refuelings is one way to measure the 

improvement in the vehicles’ capability and the way in 

which they are actually being driven. 

3.3 Onsite Hydrogen Production Cost

Cost estimates from the Learning Demonstration energy 

company partners were used as input to an H2A analysis 

to project the hydrogen cost for 1,500 kg/day early market 

fueling stations (H2A is DOE’s suite of hydrogen analysis 

tools, with the H2A Production model focused on 

calculating the costs of producing hydrogen). Results 

indicate that on-site natural gas reformation could lead to a 

price range of $8-$10/kg, and on-site electrolysis could 

lead to a range of $10-$13/kg hydrogen cost. While these 

results do not achieve the $3/gge cost target, two external 

independent review panels commissioned by DOE 

concluded that distributed natural gas reformation could 

lead to a price range of $2.75–$3.50/kg [5] and distributed 

electrolysis could lead to a price range of $4.90–$5.70/kg

[6]. Therefore, this objective was met outside of the 

Learning Demonstration project.

3.4 Overall Performance Summary

We have summarized the previously discussed key 

performance numbers, along with other metrics of interest 

such as fuel economy and fuel cell efficiency, and 

compared them to DOE targets in Table 2. This table 

shows that this project has exceeded the expectations 

established in 2003 by DOE, with all of the key targets 

being achieved except for on-site hydrogen production 

cost, which would have been difficult to demonstrate 

through this project. 

Additional data accumulated and analyzed in 2010 – 

2012 will assess the latest generations of FCEV 

technology, which include improvements over the secondgeneration systems analyzed in the results to date. Future 

assessments will also include data analysis from many 

new hydrogen stations being commissioned in California, 

all of which will have 700-bar fueling capability. 
6 

4. Other Vehicle Results

4.1 Fuel Cell System Efficiency

Researchers from the car companies measured fuel cell 

system efficiency from select vehicles on a vehicle chassis 

dynamometer at several steady-state points of operation. 

NREL worked with the data and the companies to ensure 

that appropriate balance-of-plant electrical loads were 

included. This ensured that the results were comparable to 

the target and based on the entire system rather than just 

the stack. DOE’s technical target for net system efficiency 

at one-quarter power is 60%. Baseline data from the four 

Learning Demonstration teams several years ago showed a 

range of net system efficiency from 51% to 58% for firstgeneration systems, which was very close to the target. As 

second-generation vehicles were introduced, the 

companies also performed baseline dynamometer testing 

that revealed an efficiency of 53% to 59% at one-quarter

power, within one percentage point of the target (Figure 

6). We have expanded this CDP to include a comparison 

of the efficiency at full power, where DOE’s target was 

50% net system efficiency. The data show first-generation 

systems as having 30% to 54% efficiency at full power 

while second-generation systems have 42% to 53 % 

efficiency, exceeding the 50% target. 

4.2 Voltage Transients

In discussions with fuel cell researchers, the voltage 

cycling of the stack was identified as something that 

would be worth the team investigating further. Prior to 

this, only the amount of time spent at different voltages 

was evaluated, and not the rate of change of the voltage or 

the number of times the voltage changed. Our overall 

approach was to 1) define a voltage transient cycle, 2) find 

voltage transient cycles in the on-road stack data, and 3) 

categorize and collect voltage transient cycle details.

We found a relatively symmetric distribution of the 

magnitude of voltage change about 0, with most of the 

cycles lasting less than 15 seconds. Once we had the 

voltage cycles characterized, the first thing we noticed was 

that the number of cycles per trip mile (and per trip 

minute) was drastically reduced between Gen 1 and Gen 2 

for at least one team by a factor of 4 (lower left portion of 

Figure 7). We found that the dominant transient cycle 

category was a “slow down, fast up” category, which was 

a slow voltage drop followed by a fast voltage rise. This 

could come from a gradual acceleration of the FCEV, 

followed by taking the foot off the accelerator pedal due to 

traffic at a stop sign or light. The frequency of each of 

these five cycle categories is now available to us as a new 

input to our multivariate analysis. We also examined the 

number of the voltage cycles that were outside of a 

threshold between 70% and 90% of maximum stack 

voltage. We found that these more extreme voltage 

transients occurred on average less than twice per mile 

(accounting for about one-quarter of all voltage transients), 

with the drop below 70% maximum stack voltage 

occurring more times per mile than the rise above 90% 

maximum stack voltage.

Vehicle Performance Metrics Gen 1 Vehicle Gen 2 Vehicle 2009 Target

Fuel Cell Stack Durability 2,000 hours

Max Team Projected Hours to 

10% Voltage Degradation 1,807 hours 2,521 hours

Average Fuel Cell Durability Projection 821 hours 1,062 hours

Max Hours of Operation 

by a Single FC Stack to Date 2,375 hours 1,261 hours

Driving Range 103-190 miles 196-254miles 250 miles

Fuel Economy (Window Sticker) 42 – 57 mi/kg 43 – 58 mi/kg no target

Fuel Cell Efficiency at 1⁄4 Power 51 - 58% 53 - 59% 60%

Fuel Cell Efficiency at Full Power 30 - 54% 42 - 53% 50%

Infrastructure Performance Metrics 2009 Target

H2 Cost at Station (early market)*

On-site natural gas 

reformation

$7.70 - $10.30

On-site 

Electrolysis 

$10.00 - $12.90

$3/gge

Average H2 Fueling Rate 0.77 kg/min 1.0 kg/min

*Outside of this project, DOE independent panels concluded at 500 replicate stations/year:

Distributed natural gas reformation at 1500 kg/day: $2.75-$3.50/kg (2006)

Distributed electrolysis at 1500kg/day: $4.90-$5.70 (2009)

Table 2: Learning Demonstration key performance metrics summary
7 

4.3 Fuel Cell System Power Density and Specific 

Power 

DOE’s target for fuel cell system power density in 2010 

and 2015 is 650 W/L and for fuel cell system specific 

power is 650 W/kg. System level data were gathered from 

the fuel cell teams and aggregated into ranges for first- and 

second-generation systems separately. First-generation 

fuel cell systems had a specific power of 183 to 323 W/kg, 

while second-generation systems improved to a range of 

306 to 406 W/kg. Fuel cell system power density, on the 

other hand, stayed the same or dropped slightly (staying in 

the range of 300 to 400 W/L), perhaps because the Gen 2 

systems had more balance of plant in order to support the 

freeze tolerance required.

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

10

20

30

40

50

60

Net System Power [%]

Efficiency [%]

Fuel Cell System1 Efficiency2

 Eff. at 25% Pwr Eff. at 100% Pwr

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

Gen1 51 - 58% 30 - 54%

Gen2 53 - 59% 42 - 53%

DOE Target at 25% Power

DOE Target at 100% Power

Gen 1 Efficiency Range

Gen 2 Efficiency Range

NREL CDP08

Created: Sep-02-09 11:27 AM

1

 Gross stack power minus fuel cell system auxiliaries, per DRAFT SAE J2615. Excludes power electronics and electric drive.

2

 Ratio of DC output energy to the lower heating value of the input fuel (hydrogen). 

3

 Individual test data linearly interpolated at 5,10,15,25,50,75,and 100% of max net power. Values at high power linearly extrapolated 

 due to steady state dynamometer cooling limitations.

Figure 6: Fuel cell system efficiency, comparing Gen 1 and Gen 2

0 2 4 6 8 10 12 14 16 18 20

0

5

10

15

20

Cycle Per Mile

Trip Frequency [%]

Number of Cycles1

 per Trip Mile

0 2 4 6 8 10 12 14 16 18 20

0

10

20

30

40

50

60

Cycle Per Min

Trip Frequency [%]

Number of Cycles1

 per Trip Minute

Gen1 Gen2

0

10

20

30

40

Cycle per Mile

Range of Fleet Average Cycle1 per Mile

Gen1 Gen2

1

2

3

4

5

6

7

Cycle per Min

Range of Fleet Average Cycle1 per Min

NREL CDP74

Created: Mar-22-10 4:46 PM 1) A fuel cell voltage transient cycle has a decrease and increase with a minimum delta of 5% max stack voltage.

Figure 7: Fuel cell voltage transients, comparing Gen 1 and Gen 2
8 

Because of the attention that plug-in hybrid vehicles 

were getting, we were asked to generate fuel cell system 

power density and specific power results that also included 

the hydrogen storage, and then compare the results to the 

FreedomCAR targets. We found that while Gen 1 to Gen 

2 showed significant progress, the 178 to 261 W/kg was 

still shy of the 325 W/kg FreedomCAR research goal 

when the hydrogen storage system was included. The fuel 

cell system power density, when the hydrogen storage was 

included, came extremely close (with both Gen 1 and Gen 

2) to satisfying the 2010 and 2015 FreedomCAR research 

goal of 220 W/L (Gen 1 was 152 to 214 W/L, and Gen 2 

was 127 to 213 W/L). This indicates that fuel cell systems 

are a relatively compact means of storing both energy and 

power relative to batteries.

5. Infrastructure Results – Fueling Rates

Hydrogen vehicle refueling needs to be as similar as 

possible to conventional vehicle refueling to allow an 

easier commercial market introduction. Over 25,000 

refueling events have been analyzed to date, and the 

refueling amount, time, and rate have been quantified. 

The average time to refuel was 3.26 minutes with 86% of 

the refueling events taking less than 5 minutes. The 

average amount per fill was 2.13 kg, reflecting both the 

limited storage capacity of these vehicles (approximately 4 

kg maximum) and peoples’ comfort level with letting the 

fuel gauge get close to empty (shown in previous papers). 

DOE’s initial target refueling rate is 1 kg/min, and these 

Learning Demonstration results indicate an average of 

0.77 kg/min, with 23% of the refueling events exceeding 1 

kg/minute (Figure 8). Therefore, we can conclude that 

high-pressure gases are approaching adequate refueling 

times and rates for consumers; however, the challenge is 

still in packaging enough high-pressure hydrogen onboard 

to provide adequate range or finding alternate advanced 

hydrogen storage materials that can replace the need for 

high-pressure tanks.

The refueling histogram in Figure 8 includes all types of 

refueling events. There has been much interest from 

industry and from the codes and standards community 

about the potential for communication fills to occur at a 

higher rate and with a more complete fill. A 

communication fill means that the vehicle communicates 

data about the state of its hydrogen storage tank(s) to the 

refueling station, such as tank temperature, pressure, and 

max pressure rating. The average fill rate for all 

communication fills is 0.86 kg/min vs. 0.66 kg/min for 

non-communication fills, with 30% and 12%, respectively, 

exceeding DOE’s 1 kg/min target. We can thus conclude 

that communication fills in this project are, on average, 

faster than non-communication fills.

Another partition of the fueling rate data we performed 

was by the storage system employed by each vehicle, 

comparing the fueling rate for 350-bar and 700-bar fills. 

Two major conclusions can be drawn from the results. 

The first is that the project has experienced many more 

350-bar fills (19,659) than 700-bar fills (5,590), since the 

700-bar fuelings mainly began with the second-generation 

vehicles halfway through the project. The second is that 

the fueling rate for the higher pressure fills is still slower 

than the lower pressure fills, with 29% of the 350-bar fills 

exceeding 1 kg/min and only 4% of the 700-bar fills 

exceeding the target. The average fill rate for 350-bar fills 

is 0.82 kg/min, while the average rate for 700-bar fills is 

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

Avg Fuel Rate (kg/min)

Number of Fueling Events

Histogram of Fueling Rates

All Light Duty Through 2009Q4

5 minute fill of

5 kg at 350 bar

3 minute fill of

5 kg at 350 bar

25464 Events

Average = 0.77 kg/min

23% >1 kg/min

2006 MYPP Tech Val Milestone

2012 MYPP Tech Val Milestone

NREL CDP18

Created: Mar-09-10 3:18 PM

Figure 8: Fueling rates for over 25,000 events, all types included
9 

0.63 kg/min. This does not appear to be a limitation of the 

technology, as very high fill rates at 700 bar have been 

demonstrated in Germany and Canada, but rather a 

reflection of the current technology that has been deployed 

in this first wave of 700-bar stations in the U.S. Station 

data received in the coming years from the new stations in 

California should demonstrate the full capability of 700-

bar fueling. 

In the final fueling rate analysis, we have sliced the 

same data by year. We found the number of fueling events 

has increased year-to-year during each of the 5 years of the 

project to date. While the fueling rate initially increased 

from 0.66 kg/min to 0.74 kg/min to 0.81 kg/min, it has 

now settled at a value of 0.77 kg/min for the last two 

years. Due to the number of automotive companies being 

reduced from four to two in 2010, the overall number of 

fueling events will decrease until the new California 

stations come online.

6. Conclusions and Future Directions

NREL has now completed the first five years of the 

seven-year project with 144 vehicles deployed in fleet 

operation, 23 project refueling stations constructed, and no 

major safety barriers encountered. We have analyzed data 

from 436,000 individual vehicle trips covering 2.5 million 

miles traveled and 130,000 kg hydrogen produced or 

dispensed. We have published 80 technical CDPs to date 

and made them directly accessible to the public from an 

NREL Web site [7]. We have summarized the key project 

performance numbers, along with other metrics of interest 

such as fuel economy and fuel cell efficiency, and 

compared them to DOE targets in Table 1. The table 

shows that this project has exceeded the expectations 

established in 2003 by DOE, with all of the key targets 

being achieved except for onsite hydrogen production cost, 

which would have been difficult to demonstrate through 

this project. 

From all of the results that we have generated, it is our 

conclusion that FCEVs have advanced rapidly in the last 

five years, and are expected to continue at this same rate of 

development in the next five years. There do not appear to 

be any major technical hurdles that the automotive 

companies and their suppliers cannot overcome, and they 

appear to have a glide-path to getting the costs down to a 

manageable incremental cost. We therefore expect 

continued progress to lead to market-ready vehicles in the 

2015 timeframe. Several vehicle manufacturers will 

introduce thousands of vehicles to the market in that 

timeframe, and the hydrogen community will have its first 

true test of whether the technology will be embraced by 

the public. 

Additional data accumulated and analyzed in 2010–

2012 will assess the latest generations of FCEV 

technology, which include improvements over the secondgeneration systems included in the results to date. NREL 

will create new and updated CDPs based on data collected 

through June 2010 (Fall 2010 CDPs) and present results 

for publication in the fall. We will support the automotive 

manufacturers, energy companies, and state organizations 

in California in coordinating early infrastructure plans. 

We will gather and analyze data from a hydrogen fueling 

station in Burbank, California, which has a relatively highrate of onsite hydrogen production from natural gas, along 

with many new stations that are being opened in California 

in the next year. Future assessments will include data 

analysis from many of the new hydrogen stations being 

commissioned in California, all of which will have 700-

bar fueling capability. 

NREL will continue to identify opportunities to feed 

findings from the project back into the DOE Vehicle 

Technologies and Fuel Cell Technologies programs and 

industry R&D activities to maintain the project as a 

“learning demonstration.” We will continue to gather data 

from FCEVs and hydrogen stations through 2011, and 

publish the Spring 2011 and Fall 2011 CDPs and likely

one final set of results in Spring 2012. As the last 

expected deliverable from this project, we will write a 

final summary report for publication, which will both 

include new results from the final two years as well as 

reference and build on the results included in the 2010 

interim progress report. All 80 CDPs published to date are 

directly accessible from our Hydrogen Technology 

Validation Web site [7]. 

7. References

[1] Wipke, K., Sprik, S., Thomas, H., Welch, C., Kurtz, J., 

“Learning Demonstration Interim Progress Report - Summer 

2007,” NREL/TP-560-41848, June 2007.

[2] Wipke, K., Sprik, S., Kurtz, J., Thomas, H., “Learning 

Demonstration Progress Report—September 2007,” NREL/TP560-42264, November 2007.

[3] Wipke, K., Sprik, S., Kurtz, J., “Learning Demonstration 

Progress Report—Spring 2008,” NREL/TP-560-42986, April 

2008. 

[4] Wipke, K., Anton, D., and Sprik, S., “Evaluation of Range 

Estimates for Toyota FCHV-adv Under Open Road Driving 

Conditions,” prepared under SRNS CRADA number CR-04-003, 

August 2009.

[5] Fletcher, J., and Callaghan, V., “Evaluation Cost of 

Distributed Production of Hydrogen from Natural Gas – 

Independent Review,” NREL/BK-150-40382, October 2006.

[6] Genovese, J., Harg, K., Paster, M., and Turner, J., “Current 

(2009) State-of-the-Art Hydrogen Production Cost Estimate 

Using Water Electrolysis – Independent Review,” NREL/BK6A1-46676, September 2009.

[7] http://www.nrel.gov/hydrogen/proj_learning_demo.html 

8. Primary Author

Keith Wipke, Senior Engineer and 

Manager of Hydrogen Analysis

Tel. 1.303.275.4451

Email: keith.wipke@nrel.gov

Mr. Wipke is a Senior Engineer and Manager 

of Hydrogen Analysis at the National 

Renewable Energy Laboratory, where he has 

worked in the area of advanced vehicles for 

over 17 years. He has responsibility for staff working on NREL’s 

hydrogen Technology Validation, Infrastructure Analysis, and 

Education activities. He received his master’s degree in 

mechanical engineering from Stanford University.
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Entering a New Stage of Learning from the U.S. Fuel Cell Electric 

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14. ABSTRACT (Maximum 200 Words)

The National Fuel Cell Electric Vehicle Learning Demonstration is a U.S. Department of Energy (DOE) project that 

started in 2004. The purpose of this project is to conduct an integrated field validation that simultaneously examines 

the performance of fuel cell vehicles and the supporting hydrogen infrastructure. The DOE’s National Renewable 

Energy Laboratory (NREL) has now analyzed data from over five years of the seven-year project. During this time, 

over 144 fuel cell electric vehicles have been deployed, and 23 project refueling stations were placed in use.

15. SUBJECT TERMS

National Fuel Cell Electric Vehicle Learning Demonstration; Fuel Cells; hydrogen; vehicles; alternative fuel; National 

Fuel Cell Electric Vehicle Learning Demonstration; World Battery, Hybrid and Fuel Cell Electric Vehicle Symposium & 

Exhibition; hydrogen vehicles; vehicle deployment

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