R&D Focus Areas Based on 60,000 hr Life PEM Water Electrolysis Stack ExperiencePEM Water Electrolysis Stack Experience

E. Anderson, K. Ayers, and C. Capuano

First International Workshop on Durability and Degradation Issues in PEM Electrolysis Cells and its Componentsy p

Freiburg, Germany12 March 2013

™ ® Proton, Proton OnSite, Proton Energy Systems, the Proton design, StableFlow, StableFlow Hydrogen Control System and design, HOGEN, and FuelGen are trademarks or registered trademarks of Proton Energy Systems, Inc.

Any other brands and/or names used herein are the property of their respective owners.

Proton OnSiteManufacturer of packaged products, systems• Proton Exchange Membrane (PEM) expertise• H2 generation by water electrolysis• N generation by membrane and CMS• N2 generation by membrane and CMS• Founded in 1996• 100,000 ft2 manufacturing/R&D facility• ISO 9001:2008 registeredISO 9001:2008 registered

Over 2000 systems in more than 75 countries

P t ’ W ld H d t i W lli f d CT

2

Proton’s World Headquarters in Wallingford, CT

Proton’s Markets, Products & CapabilitiesPower Plants • Complete product development,

Heat Treating

Semiconductors

Laboratories

p p p ,manufacturing & testing

• Turnkey product installation• World-wide sales and service• Containerization and hydrogen

t l tiLaboratories

Government

storage solutions• Integration of electrolysis into RFC

systems

2011: C-Series

2000:S-Series1-2 kg/day13 b

2006:HPEM0.5 kg/day138 b

2009:OutdoorHPEM2 kg/day

65 kg/day, 30 bar

Steady History of Product Introduction

1999: GC

13 bar

2003:H S i

138 bar 165 bar

2006:StableFlow®

2010:300-600 mL/min13 bar

H-Series4-12 kg/day30 bar

StableFlow®Hydrogen Control System

Lab Line

Over 10 MW Shipped Future Growth from MW Scale PEM Electrolysis

3

Over 10 MW Shipped – Future Growth from MW-Scale PEM Electrolysis

Today…• Proton’s PEM-based hydrogen generators are

demonstrating excellent reliability in industrial li tiapplications

• Cell stack technology is the most reliable component in the systemcomponent in the system

• New energy applications present capital as well as operating cost challengesas operating cost challenges

• Necessary technology advances are the biggest risk to established durability and reliabilityrisk to established durability and reliability

• Meaningful accelerated stress tests could reduce that riskreduce that risk

4

Critical Needs for Energy Storage

• Renewable energy is growing rapidly world-wide in both wind and solar– Inherent intermittency has more impact as RE becomes a

larger portion of the grid capacity

– Up to 20-40% of wind energy can be stranded without storage

• Need generation technologies for storing excessNeed generation technologies for storing excess renewable capacity & balancing loads on the grid

• Energy storage can also provide a linkage between• Energy storage can also provide a linkage between utilities & transportation

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H2 Energy Product Attributes• Reliability – Cannot afford down-time or high replacement

costs

• Cost – Price targets for energy market apps more difficult (Capex vs. Opex)

L d f ll i• Load-following – Need to handle fast response of varying renewable power

• Operating Range Need to handle wide variability of• Operating Range – Need to handle wide variability of available renewable power(i.e. 100% turndown)

• Efficiency – Cost of electricity impact (Opex)

• Scale – MW-class electrolysis requiredScale MW class electrolysis required

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PEM Electrolysis Reliability• Cell Examples:

– Membrane chemical stability– Catalyst voltage decaySystem Level– Material oxidation– H2 embrittlement– Gas crossover

• Stack Examples:Stack Level

Stack Examples:– Active area and seal area

pressure– Flowfield component

tolerances

Cell Level

to e a ces– Interface differential pressure

• System Examples:– Operating profile

Reactant purity– Reactant purity– Power quality– Electromechanicals

(sensors, pumps, valves,…)

7

Established PEM Stack Durability

~60,000 hour life demonstrated in commercial stack designs2.6

3.0

ential

)

2003 Stack Design:1.3 A/cm2

200 psig (13 barg)

Proton Energy SystemsIn-House Cell Stack Endurance Testing

New designs have nodetectable voltage decay

1.8

2.2

Average Cell Pote

(Volts, 50oC 1.3 A/cm

4 µV/cell hr Decay Rate

2005 Stack Design:1.6 A/cm2

1.40 10,000 20,000 30,000 40,000 50,000 60,000

Operating Time (Hours)

Non Detectable Decay Rate

>20,000 hour lifedemonstrated at 165 bar in high pressure stack designhigh pressure stack design

Strong lineage to low pressure design

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pressure design

Cell Stack Reliability – Over the past 6 yrs…Part Quality: 292Million Cell HoursPart Quality: 292 Million Cell Hours

Total Cells Replaced

Hundreds of millions of cell-hours of fieldTotal Cells Replaced

Original Cells in Operation

of cell hours of field experience>> 99% reliability

Defect Breakdown

90%Customer ContaminationMaterial Supplier IssueMisalignment/part defect

Corrective actions in place to address

2 f il d9%

0.31%

Misalignment/part defectUnknown/System Operation top 2 failure modes

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1.25%

Technology Roadmap Development

• Clearly defined pathways enable directed research– Product cell stack and balance-of-plantProduct, cell stack, and balance of plant

• Balance portfolio with near and long term R&D• Leverage 3rd party funding to subsidize internal R&D

– Utilize military and aerospace as early adopters– Develop key partnerships to broaden skill base

• Feed into commercial markets as proven• Feed into commercial markets as proven

NSF ARPA- E DOE-EERE ONR CERL TARDECU.S. Funding Agencies:

Materials Feasibility Applied Deployable Prototypesresearch Demonstration R&D

Development Stage/Risk Level

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research Demonstration R&D

Cost Reduction InitiativesNoble Metal Reduction Flow Field CostNoble Metal Reduction Flow Field Cost3M NSTF electrode:5% of current 1 6

1.8

2

2.2

l (Vo

lts)

5% of current catalyst loading

1

1.2

1.4

1.6

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

Potentia

Current Density (Amps/cm2)

3M Cathode #1, 8 mil total3M Cathode #2, 8 mil totalProton Baseline , 7 mil

2.5

2.6

2.7

A i t t

1 7

1.8

1.9

2

2.1

2.2

2.3

2.4

Potential (V)

Approximate current production range

Adv membrane: Enables 2X current(lower Capex)

New design with ~50% less metal

1.4

1.5

1.6

1.7

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

Current Density (A/cm2)

90 micron

60 micron

Reduced voltage(lower Opex)

Lower Cost Membranes

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Lower Cost Membranes

Electrolysis Membranesy• Typically 170-250 microns thick versus 25-50

microns for fuel cellsmicrons for fuel cells• Need reinforcement to withstand high pressures• Durability requirements make qualification• Durability requirements make qualification

challenging• Accelerated testing: 2000

25003000

AMPS8_TRND H2PRES8_TRND

Accelerated testing: combination of pressure,voltage, and temperature 1000

1500

2000

urre

nt D

ensi

ty (a

sf)

1500

2000

2500

Pres

sure

(PSI

G)

g pcycling

0

500

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00

Cu

0

500

1000

12

Time Minutes (min)

Efficiency Needs and Progress: Membrane• Reduce Membrane Thickness• Increase Operating Temperature

2 2

2.3

2.4

Technology Progression

Baseline, 50CAdvanced Oxygen Catalyst, 50CAdvanced membrane, 80C Current Stack

1.9

2

2.1

2.2

tial (Volts)

Advanced membrane, 80CAdvanced cell design, 80C

Current Stack(~70% Eff (HHV)

Advanced membranes show pathway to high efficiency

1.6

1.7

1.8

Potent

Advanced Stack pathway to high efficiency

Durability promising but needs to be proven at 80C

1.4

1.5

0 0.5 1 1.5 2 2.5 3

Current Density (A/cm2)

Advanced Stack (>86% Eff (HHV)

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Cost Needs and Progress - Catalystg y

• Engineered structures for ultra low PGM loadingsultra-low PGM loadings

2 2 3M NSTF

1.8

2

2.2

Volts)

3M NSTF

1 2

1.4

1.6

Potential (V

3M Cathode #1, 8 mil total3M Cathode #2, 8 mil totalProton Baseline , 7 mil

1

1.2

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0Current Density (Amps/cm2)

Brookhaven GDE approach

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Polarization curves: 3M loading < 1/20th baseline, Brookhaven <1/30th loading

Cost Needs and Progress: Flow Fields• New bipolar cell assembly design: 50% metal reduction

• Alternative coatings: Eliminates process stepsand mitigates hydrogenand mitigates hydrogenembrittlement

15

Flowfield/Bipolar Plate Reliabilityp y

• Typical materials are semi-precious metals

100%

Baselinep– Precious metal coatings

added to reduce resistance• Susceptible to oxidation

(anode) or embrittlement60%

80%

ke vs. Baseline Treatment 1

Treatment 2

Nitrided

(anode) or embrittlement (cathode) with prolonged operation

• Need lower cost alternatives 20%

40%

Hyd

rogen Uptak

Need lower cost alternatives• Investigating impact of

process methods & alternative non-precious metal coatings

0%0 200 400 600 800

Time (h)

on durability Accelerated H2 Exposure Testing(100 hrs → 10 yr operation)

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Intermittency and Variable Load Input• Electrolysis is well suited to load following

– Stable performance– Rapid response time to current signal– Tolerance to variable power input

50 ms response time demonstratedtime demonstrated

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Courtesy of NREL

Grid Support Using PEM Electrolysis*ApproachAC pp• Simulate deviation on diesel generator-

based AC mini-grid• Trigger electrolyzer at +/- 0.5 Hz from

60 Hz add or shed load to stabilize AC

AC mini-grid

60 Hz, add or shed load to stabilize AC grid by regulating frequency

60.5

61

Hz)

PEM Electrolyzer Results• Responded as

PEM Grid-Tied: Stack Step 25% to 100% 59

59.5

60

60.5

0 0 5 1 1 5 2

Freq

uenc

y (H

LB 10-0kW PEM 30kW

LB 10-0kW PEM 30-40kW

• Responded as needed

• Re-stabilization achieved in

3

4

5

2030405060

er L

evel

(V)

rren

t (A

rms)

p

~150 msresponse

0 0.5 1 1.5 2Time (sec)

60

60.5

61

cy (H

z)

LB 0-10kW PEM 40kW

LB 0-10kW PEM 40-30kW

achieved in less than 1 sec

• Large loads & varied trigger

1

2

01020

0 0.05 0.1 0.15 0.2

Trig

ge

AC C

u

Time (sec)

CurrentTrigger

response

59

59.5

0 0.5 1 1.5 2

Freq

uenc

Time (sec)

Red line – Without PEM Load

ggpoints can be use to optimize response

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Gold line – With PEM load*Courtesy of K Harrison, NREL, 2011

Adverse Environmental Conditions

2.10

• Short stack freeze-thaw cycle testing

2.17%

2.05

Avg. Cell Potential

% Change vs. Baseline

Operating Conditions1.8 A/cm2, 50°C

2.00

tial (Volts)

0.98%

0 53%

0.94%

0.60%

1.95

Potent

0.53%

0.41%

1.85

1.90

B li 1 t F 2 d F 3 d F 4th F 5th F 356th FBaseline 1st Freeze 2nd Freeze 3rd Freeze 4th Freeze 5th Freeze 356th Freeze

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Other Reliability Concerns

• Transition to multi-stack systems– Increased system complexity– Stack-to-stack interactions

• Power conversion/power quality issues• Sensing in unique environments

From Single to Multi-Stack SystemsFrom Single to Multi Stack Systems

HOGEN® H Series HOGEN® C SeriesUp to three stacks per systemHOGEN®

S Series

HOGEN®

GC

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Summary

• Industrial PEM electrolysis systems have excellent reliability track recordexcellent reliability track record

• New energy applications will challenge that reliability as technology advancements to drive y gycost and reliability are adopted

• Market needs for hydrogen energy storage are emerging rapidly

• Development of AST protocols could shorten d l t ti hil d i i k i d tdevelopment time while reducing risk in order to meet the growing market needs

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