Innovation for Our Energy Future Round Robin Testing

Innovation for Our Energy Future Round Robin Testing of Commercial Hydrogen Sensor Performance – Observations and Results NHA Hydrogen Conference & Expo Long Beach CA W. Buttner, R. Burgess, C. Rivkin, M. Post, L. Brett, G. Black, F. Harskamp, P. Moretti May 3 rd – 6 th, 2010 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.

Sensors Uses are Well Established Common Uses: – Used Every Day – Smoke/CO Detectors – Safety Alerting – Oxygen Sensors (cars) – Equipment Maintenance – Impact Sensors (airbags) – Seamless and Unnoticed – Infrared (remote control) – Integral part of modern life – Motion (stoplights) 2 Innovation for Our Energy Future

Sensors for the Safe Use of Hydrogen chemical safety sensors will be a critical aspect to safe hydrogen use in the future: – Sensors will alarm when unsafe conditions are present – Automatic shutdown can be initiated by sensors – Hydrogen Codes & Standards will require the use of sensors • NFPA 52 – Vehicular Gaseous Fuel Systems Code (9. 2. 3. 1) • NFPA 55 – Compressed Gases and Cryogenic Fluids Code (7. 9. 3. 2. 1) 3 Innovation for Our Energy Future

Sensors - Sensing Element vs. Detectors Sensing Element: • A small device that as the result of a chemical interaction or process between the analyte gas and the sensor device transforms chemical or biochemical information of a quantitative or qualitative type into an analytically useful (electronic) signal. Detector: • Comprised of sensing element and control electronics to generate a response (signal) that is directly related to concentration of the target analyte. • From ISO 26142: Assembly with an integrated or a remote hydrogen sensor that is intended to detect and measure the hydrogen volume fraction over a declared measuring range. 4 Innovation for Our Energy Future

Hydrogen Sensors Hydrogen Sensor Types (Sensing elements) • • Catalytic Bead (Pellistor) Electrochemical Metal Oxide (MOX) Metal Semiconductor (MOSFET) Optical Palladium Thin Film Surface Acoustic Wave (SAW) Thermal Conductivity Signal can be impacted (sensing element and detector) • • • Hydrogen Environmental effects (T, P, RH) Chemical effects (interferences, poisons) Physical Parameters (age, mechanical stresses) Human factors (deployment parameters) 5 Innovation for Our Energy Future

Sensor Performance Specifications DOE Hydrogen Sensor Targets – Multi-Year Research, Development & Demonstration Plan – Measurement Range: 0. 1% to 10% – Operating Temperature: -30°C to 80°C – Response Time: Faster than One Second – Accuracy: 5% of Full Scale – Gas Environment: Ambient Air, 10% to 98% Relative Humidity – Lifetime: 10 Years – Interference Resistant (e. g. , Hydrocarbons) International Standards (ISO 26142) • Hydrogen detection apparatus -- Stationary applications National Standards (UL 2075) • Standard for Safety Gas and Vapor Detectors and Sensors 6 Innovation for Our Energy Future

JRC Hydrogen Sensor Test Facility Test sensors under precisely controlled and monitored conditions – Gas Parameters • • Flow rate (25 to 1000 sccm) Composition – Environmental Parameters • • • Temperature (-40 to +130°C) Pressure (100 Pa to 250 k. Pa) Moisture (10 to 100% RH) – Accommodates multiple sensors – System control • • Attended operation Manually run and monitored – Extensive Sensor Testing • • 7 IJHE 33 (2008) 7648 -7657 IJHE 34 (2009) 562 -571 Innovation for Our Energy Future

NREL Safety Sensor Test Laboratory Test sensors under precisely controlled and monitored conditions – Gas Parameters • • Flow rate (25 to 1000 sccm) Composition – Environmental Parameters • • • Temperature (-25 to +80°C) Pressure (subambient to 1. 4 Bar) Moisture (<5 to 95% RH) – All common electronic interfaces – Accommodates multiple sensors – Fully automated control • • Around-the-clock operation Remotely run and monitored – Sensor Testing since 2008 • New Fixture Commissioned 2009 8 Innovation for Our Energy Future

Comparison of Facilities – similar but not identical Sensor chamber Environmental Control • NREL: 4 Liter; 1 L/min standard flow • Unique T, P, moisture control and monitoring systems • JRC: 2. 4 L; 0. 35 to 1 L/min standard flow • Different suppliers of gas standards Operational Logging Profile • NREL: Automated, remotely accessible, unattended around-the-clock • NREL: Fixed Rate • JRC: Variable (fast during change) • JRC: Automated with manual control, restricted operational time Step Duration Personnel • NREL: Sensor Steady-State • JRC: Sensor Steady-State 9 Innovation for Our Energy Future

Manufacturers and Stakeholders Benefits: – – Unbiased platform to test technology test data and analytical feedback is provided Specific test data results is kept confidential General data will be compiled and made available to stakeholders – “waiting list” of interested manufacturers exist Working with manufacturers will ensure that emerging commercial technologies meet end-user needs Working with stake-holders will assist in selection of proper technology 10 Innovation for Our Energy Future

SINTERCOM Sensor INTERlaboratory COMparison (SINTERCOM) • International Collaboration • The National Renewable Energy Laboratory (NREL) of the US Department of Energy (DOE) • Institute for Energy of the European Commission’s Joint Research Centre (JRC) • Round-Robin Testing • Independent, unbiased assessment of sensor performance • Opportunity to test more sensors • Improvement of test methods 11 Innovation for Our Energy Future

The SINTERCOM Protocol Technology Selection & Procurement • Identify and acquired representative technology type • Provide 3 units to each participating laboratory Technology Testing • Round 1: Analytical performance assessment • Performed in each lab on 3 units • Round 2: Analytical performance assessment; • Exchange 3 units and repeat Round 1 protocol • Validation of laboratory • Round 3: Interferent / poison and Long-term stability • Exchange and Compare Data after each round 12 Innovation for Our Energy Future

SINTERCOM Round-Robin Test (Round 1) Test Plan Standard Condition • 25°C, 1 Bar, 50% RH (unless noted) • Initial/Final Sensor Calibration • • Standard Condition First test of Round 1 1% and 2% Certified Standards First and last test in each round • Linear Range Test • Standard condition • 7 concentrations (0 to 2%) • ascending and descending 13 Innovation for Our Energy Future

SINTERCOM Round-Robin Test (Round 1) Test Plan • Short Term Stability • Standard Condition • 4 concentrations • 0. 0, 0. 2, 1. 0, 2. 0 % Hydrogen • Repeated 9 X in 48 hours • Environmental Stresses • • Temperature (-20 to 85°C) Pressure (0. 8 to 1. 2 Bar) Moisture (<5 to 85%) “Standard Condition” • 1 variable parameter • Performed 1 X for each condition • Range restricted to manufacturer spec 14 Innovation for Our Energy Future

Test Sequence and Parameters (Round 1 and Round 2) 15 Innovation for Our Energy Future

SINTERCOM Round-Robin Test NREL • NREL tests on Unit 1 JRC • JRC tests on Unit 2 • 1 L/min Flow Rate • Fixed Step Duration 1 hour • Final Indication after 59 min • • Test performed at 0, 0. 2, 1. 0, 2. 0 0. 35 L/min Flow Rate Fixed Step Duration 45 min Final Indication after 44 min • Test performed at 0, 0. 6, 1. 0, 2. 0 • 0. 2 below LDL of instrument • 16 Protocol adjusted Innovation for Our Energy Future

SINTERCOM: Short-Term Stability (1%) As received (no recalibration) NREL Unit 1 (♦) JRC Unit 2 (□) “Field” Calibrated Vendor NREL Unit 1 (♦) JRC Unit 2 (□) ISO Instrument Performance in SINTERCOM (SHORT TERM STABILITY) - Unit 1 (♦) NREL and Unit 2 tested at JRC (□) - Excellent consistency between laboratories and between two units - Similar results for all six units - Sensor performance as compared to ISO (▬) and Vendor Specifications (▬) - Sensor meets vendor’s spec (± 20%), needs “calibration” for ISO (± 10%) - Specifications are “arbitrary” and depend on USER REQUIREMENTS 17 Innovation for Our Energy Future

SINTERCOM: Temperature Stress Test ISO Vendor NREL Unit 1 (♦) JRC Unit 2 (□) Instrument Performance in SINTERCOM (TEMPERATURE STRESS TEST) - Unit 1 (♦) NREL and Unit 2 tested at JRC (□) - Excellent consistency between laboratories and between two units - Similar results for all six units - Sensor performance as compared to ISO (▬) and Vendor Specifications (▬) - Sensor meets vendor’s specification (± 20%) except at very low T - Sensor meets ISO T specification (± 30%) except at very low T - Specifications are “arbitrary” and depend on USER REQUIREMENTS 18 Innovation for Our Energy Future

SINTERCOM: Pressure Stress Test ISO Vendor NREL Unit 1 (♦) JRC Unit 2 (□) Instrument Performance in SINTERCOM (PRESSURE STRESS TEST) - Unit 1 (♦) NREL and Unit 2 tested at JRC (□) - Excellent consistency between laboratories and between two units - Similar results for all six units - Sensor performance as compared to ISO (▬) and Vendor Specifications (▬) - Sensor meets vendor’s specification (± 20%) except at very low P - Sensor meets ISO P specification (± 30%) - Specifications are “arbitrary” and depend on USER REQUIREMENTS 19 Innovation for Our Energy Future

SINTERCOM: Moisture Stress Test ISO Vendor NREL Unit 1 (♦) JRC Unit 2 (□) Instrument Performance in SINTERCOM (Moisture STRESS TEST) - Unit 1 (♦) NREL and Unit 2 tested at JRC (□) - Excellent consistency between laboratories and between two units - Similar results for all six units - Sensor performance as compared to ISO (▬) and Vendor Specifications (▬) - Negligible effect of moisture on sensor performance - Sensor meets vendor’s (± 20%) and ISO (± 30%) specification - Specifications are “arbitrary” and depend on USER REQUIREMENTS 20 Innovation for Our Energy Future

SINTERCOM Status • Round 1 completed for initial technology • Reviewed with manufacturer and between laboratories • Round 2 is starting • Instrument Exchange completed • Round 3 is pending • Additional technology • Second technology has been selected, acquired, and distributed • Additional technology has been selected • Representative of alternative sensor types 21 Innovation for Our Energy Future

Round-Robin Testing of Hydrogen Sensors BENEFITS Sensor Interlaboratory Comparison (SINTERCOM) • Support of Technology Development • Independent, unbiased assessment of performance • Expert analysis and feed back opportunities • Exposure to international markets • Test Laboratories • Venue to critically evaluate sensor test protocols • Validate competences of participating laboratories • End-User benefits • Information on sensor performance • Importance of sensor use 22 Innovation for Our Energy Future

Summary • Sensors are reliable and well established safety components • Codes & Standards will require the use of hydrogen safety sensors • SINTERCOM is an international effort to improve hydrogen sensors • First Round testing has been completed • Strong agreement among units and between labs • Additional technology has been selected • Results will be compiled and reported 23 Innovation for Our Energy Future

Thank You The National Renewable Energy Laboratory (NREL) of the US Department of Energy (DOE) • W. Buttner, R. Burgess, C. Rivkin, M. Post Institute for Energy of the European Commission’s Joint Research Centre (JRC) • L. Brett, G. Black, F. Harskamp, P. Moretti Innovation for Our Energy Future