Reversible Solid Oxide Fuel Cell (RSOFCEL) Development at Versa Power Systems

Transcription

1 Reversible Solid Oxide Fuel Cell (RSOFCEL) Development at Versa Power Systems ENE41-2 Solid Oxide Electrolysis Systems Co-Authors: A. Wood, H. He, T. Joia, C. Brown, B.Borglum, E. Tang, M. Pastula, M. Richards, Presented by: Randy Petri

2 Contents Company Overview RSOFCEL Technical Approach SOFC Development Status Cell Performance Lifetime testing Stack Performance SOEL Development Status Cell Performance Lifetime testing Stack Performance RSOFCEL Development Status Accelerated cyclic testing RSOFCEL lifetime testing Summary Acknowledgements 2

3 FuelCell Energy is a publicly listed company (NASDAQ, FCEL) and delivers stationary fuel cells to customers in the Americas, Europe, and Asia Commercializing Molten Carbonate Fuel Cells (MCFC) & Developing SOFC Product in Parallel, for small /medium commercial/dg Versa Power Systems is a developer of high efficiency Solid Oxide Fuel Cells (SOFCs) and is a wholly owned subsidiary of FuelCell Energy Fuel Cell Energy 15 MW fuel cell park 59 MW fuel cell park Versa Power Systems operates a 33,000 ft2 R&D and pilot manufacturing facility 3

4 Global Manufacturing Footprint Manufacturing Torrington, CT Module Assembly & Stacking 65,000 ft² facility (pre-expansion) Opened 2001 North America Corporate Danbury, CT Research labs Engineering design Global Service center Conditioning SOFC Research Littleton, Colorado Calgary, Canada Research labs Asia & Europe Manufacturing Pohang, South Korea Capacity for Asian market via partner, POSCO Energy Manufacturing Ottobrunn, Germany Capacity for European market via FCES, GmbH 4

5 Integrated Fuel Cell Company Research & Development Global fuel cell technology platform Robust intellectual property portfolio Leveraging core technology for new market opportunities Sales, Manufacture & Project Execution Project development Direct Sales Global manufacturing (200+ MW capacity) Engineering, Procurement and Construction Services Operate & Maintain power plants 100+ DFC plants operating at 50+ sites globally >4 billion kwh ultra-clean power produced > 300 MW installed/backlog Fuel cell stack Four-Stack Module 1.4 megawatts Completed module 1.4 megawatts 2.8 MW power plant 5 unit fuel cell park 5

6 Reversible Solid Oxide Development Reversible Solid Oxide Cells (RSOFCELs) are energy conversion devices which can integrate renewable production of electricity and hydrogen when power generation (SOFC) and steam electrolysis (SOEL) are coupled in a system, and have the potential to maximize/firm renewable (intermittent) energy Thrust Area To advance RSOFCEL cell / stack technology in the areas of endurance and performance e - e - e - e - e - Anode 2O = u O 2 + 4e - _ O 2 O 2 Cathode O 2 + 4e - u 2O = + e - e - O = Electrolyte O = O = Electrolyte O = e - H 2 O e - Cathode 2H 2 O + 4e - u 2H 2 + 2O = + H2 H 2 Anode 2H 2 + 2O = u 2H 2 O + 4e - _ e - H 2 O 6

7 Facilities/Activities 32,000 ft 2 pilot manufacturing and fuel cell development facility As-received powders cells stacks stack modules integrated systems Development activities in both SOFC, SOEL and RSOFCEL Tape Casting Screen Printing One Step Co-Firing Test Infrastructure 7

8 Technical Approach Planar anode-supported cells (500 m) Cross-flow gas delivery Ferritic stainless steel sheet metal interconnects Stacks can be integrated into various arrangements, depending on power applications Cathode Electrolyte Anode 8

9 SOFC Cell Performance 9

10 Voltage (V) SOFC Long Term Performance Single Stack Repeat Unit Overall: Overall: 58 mv over hrs 3.17 mv or 0.32% / 1000 hrs 51 mv over 18,000 hrs (2.06 y) 2.79 mv or 0.32% / 1000 hrs Cell Stack - 81 cm 2 Active Area Furnace Temperature: 750 C Fuel: 50 H 2 :50 N 2 + 3% H 2 O, Uf = 50% Oxidant: Air, Ua = 25% Current: 40.5 A (0.5 A/cm 2 ) Test Elapsed Time (hours) 10

11 Average Cell Voltage (V) SOFC Stack Steady State Performance: 121 cm 2 x 28-Cell Overall: Overall: 66 mv over hrs 3.3 mv or 0.39% / 1000 hrs 66 mv over 20,000 hrs (2.29 y) 3.3 mv or 0.39% / 1000 hrs Cell Count: 28 Cell Active Area: 121 cm 2 Furnace Temperature: 670 C Fuel: 55 H 2 :45 N 2 + 3% H 2 O, Uf = 65% Oxidant: Air, Ua = 40% Current: 45 A (0.372 A/cm 2 ) Test GT Elapsed Time (hours) 11

12 SOFC Large Area Stack (550 cm 2 ): Long Term Performance Overall: 33 mv over 11,197 hours (1.28 y) 2.9 mv or 0.33% / 1000 hours Cell Count: 64 Cell Active Area: 550 cm 2 Furnace Temperature: 690 C Fuel: Simulated reformate, DIR= 36%, Uf = 68% Oxidant: Air, Ua = 15% Current: 160A (0.291 A/cm 2 ) GT

13 Voltage, V SOEL Status: high current density % humidity Hydrogen/air operation 1.67 V 800 C 750 C 75% efficiency HHV: V V TN750 =1.285 V A/cm A/cm A/cm A/cm A/cm Current Density, A/cm 2 High performance cells can reduce hydrogen production costs and allow system 13 integrators to achieve high water electrolysis efficiencies >75% 13

14 Voltage, V SOEL Stability Single Stack Repeat Unit Cell Stack - 81 cm 2 Active Area Furnace Temperature: 750 C Air Flow = L/min Fuel Flow = L/min Fuel (N2/Water = 1:1) Current: 40.5 A (0.5 A/cm 2 ) Degradation Rate = 9 mv/1000 hrs (0.7 % per 1000 hours) Elapsed Time, h 14

15 Voltage (V) Current (A) GT TC1 Average Voltage kw-class SOEL Stack with Large Area Cells (550 cm 2 ) mv (~3%) / 1000 hours ~45g/hour H 2 production rate Average Voltage Current Elapsed Time 15

16 Voltage, V V RSOFCEL Status: Stack Repeat Unit 50% humidity Hydrogen/air operation Glob ; RSOFC V ASR (.cm 2 ) SOEC SOFC V V Electrolyser Mode 0.8 Fuel Cell Mode H 2 O H 2 + ½ O 2 H 2 + ½ O 2 H 2 O Current Density, A/cm 2 16

17 Voltage, V RSOFCEL Accelerated Cycling Tests 1 Cell Stack - 81 cm 2 Active Area hour cycles (180) 20 min cycles (5900) Total 6,080 cycles 0.03 mv/cycle degradation Furnace Temperature: 800 C Fuel: H % H 2 O, Uf/UH 2 O = 30% Oxidant: Air, Ua = 30% Current: ± 24.3 A (0.3 A/cm 2 ) Electrolysis Voltage Fuel Cell Voltage Equivalent daily cycles 1 year 5 years 10 years 15 years Elapsed Time, h 17

18 Voltage, V RSOFCEL Stack Repeat Unit Daily Cyclic Operation Electrolysis Voltage Fuel Cell Degradation: 51 mv over 8,137 hours 6.3 mv per khours 0.6 % per khours Fuel Cell Voltage 1st Cycle hrs Operational Conditions SOFC SOEC Current A/cm 2 Temperature C Active area cm 2 Air flow slpm H2 flow slpm H2O flow slpm utilization % 338th Cycle hrs Elapsed Time, h Simulated RSOFCEL Operating Profile 24hr daily solar cycle 18

19 VPS SOEL System Implications The lower cell voltage of SOEL cells results in: about 30% lower power consumption at any given hydrogen production rate; and 4x the hydrogen production rate at any given power consumption rate. An SOEL system with higher maximum operating current limit will better match the charging rates for solar and wind based renewable energy sources. This leads to better integration to meet the energy conversion and storage needs from a wider variety of renewable energy sources. 19

20 The new EERE Project Target: reach the DOE 2020 water electrolysis efficiency (LHV) target of 78%. Approach: develop SOEL technology capable of delivering ultra high electrolysis current of more than 3 A/cm2 at up-limit water electrolysis cell voltage of ~1.6 V for 78% LHV efficiency VPS baseline cell, RSOFC-7 can deliver ~1.6V, at a high voltage of 3 A/cm 2 Perspective: a PEM-based regenerative cell will have a lower current density of less than 0.5 A/cm 2 at this voltage. Cost reduction is driven primarily by improvements in stack current density in most systems. Improvements in stack current density result in a reduction of cell active area and a corresponding decrease in material cost. 20

21 Most Recent SOEL Performance Improvements Cell Voltage, V * ECS Transactions, 33 (1) 3-15 (2010); K. E. Ayers et al Research Advances Towards Low Cost, High Efficiency PEM Electrolysis **Eric Tang, Tony Wood, Sofiane Benhaddad, Casey Brown, Hongpeng He, Jeff Nelson, Oliver Grande,. Advanced Materials for RSOFC Dual Operation with Low Degradation. s.l. : US DoE, % Efficiency LHV Thermoneutral Voltage at 800 C Regenerative PEM* RSOFC-7 Cell ** HiPoD Cell - Oct Current Density, A/cm 2 21

22 Single repeat unit tests Demonstrated power density greater than 2 W/cm 2 Cell operated over 18,000 h 0.3 % per 1000h degradation Stack testing ~1 kwe stack operated 20,000 h <0.4% per 1000h degradation ~9 kwe, large area stack operated over 11,000 h 0.33% per 1000h degradation Large area stacks up to 25kWe tested System Testing SOFC development at demonstration stage 4 x 120-cell stacks delivered to FCE and integrated into a 50kWe module now under test SOFC Status Summary 22

23 Cell Voltage, V Single repeat unit tests 3.1 A/cm2 at 75% eff,(lhv) Cell operated over 1,600 h 0.7 % (9 mv) per 1000h degradation >6,000 accelerated cycles demonstrated equivalent to >15 years of daily cycling < 0.03 mv per cycle-deg Cell operated over 8,500 h >330 reversible daily cycles 0.6% per kh degradation rate Most Recent: ~6.2 A/cm2 at 75% eff,(lhv) Stack testing Large area stack operated (early stage technology) 6-cell stack generated 45 g/hour hydrogen RSOFCEL Status Summary Thermoneutral Voltage at 800 C Current Density, A/cm 2 75% Efficiency LHV Regenerative PEM* RSOFC-7 Cell ** HiPoD Cell - Oct 2015 equates to 900 g/hour hydrogen for a 120-cell stack, or 86 kg/day hydrogen for a 4-stack quad Encouraging results are being obtained in the area of RSOFCEL Stack Development. NEXT-- Cell materials development: Ultra High Current Density Performance and improved degradation rate SOEL stack operation with latest materials technology RSOFCEL cycling stack and system testing requires demonstration

24 Acknowledgements U.S. Department of Energy National Energy Technology Laboratory U.S. Department of Energy Energy Efficiency and Renewable Energy 24

25 Thank you! 25 25

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27 HiPod Cell in Fuel Cell Operation 27