Solar and wind hydrogen energy systems for standalone power supply

Transcription

1 Solar and wind hydrogen energy systems for standalone power supply Project leader: Associate Professor John Andrews Presented by: Dr Bahman Shabani School of Aerospace, Mechanical and Manufacturing Engineering (SAMME) RMIT University Australian Association for Hydrogen Energy (AAHE) 2010 Hydrogen workshop 1

2 A Basic Standalone PV-Hydrogen System PV Array Load Load splitter MPPT DC-AC Inverter Electrolyser H 2 Storage Fuel Cell 2

3 Barriers facing solar hydrogen systems entry into the market 1- Cost 2 - Low round-trip efficiency (although still better than batteries in long-term energy storage applications) 3- Fresh water supply (but can be recycled from fuel cell) Energy market 3

4 Grand goal More energy-efficient and economically competitive systems for production of hydrogen by electrolysis from solar and wind energy sources, and utilisation for electricity generation and heat 4

5 Research projects 1- Optimal coupling of photovoltaic panels with PEM electrolysers in solar/wind hydrogen systems for remote power supply 2- Optimal coupling of wind turbines and PEM electrolysers 3- Unitised Regenerative Fuel Cells (URFCs) 4- Solar-hydrogen Combined Heat and Power (CHP) systems 5- Solid state storages for hydrogen in Solar-hydrogen systems 6- Overall control system for a solar-hydrogen system 5

6 Safety measures Safety system are used for all the hydrogen-related experiments at SAMME, RMIT 6

7 Optimal coupling of photovoltaic panels with PEM electrolysers in solar-hydrogen systems for remote power supply Dr Biddyut Paul 7

8 Conventional and direct coupling of PV array and electrolyser DC-DC Converter/MPPT Electrolyser PV Array Conventional coupling of PV-PEM electrolyser Direct coupling of PV-PEM electrolyser 8

9 Current, I (amp) Characteristics of PV Panel G=1000 W/m MPP Voltage, V (volt) Simulated I-V characteristics curve of BP 275 (75 W) solar panel showing maximum power point (MPP) line 9

10 Current, I (amp) PEM Electrolyser Characteristics Voltage, V (volt) Experimental I-V characteristics curve of StaXX7 (50 W) PEM electrolyser 10

11 Current, I PV-Electrolyser Matching MPP Electrolyser Voltage, V Matching of maximum power point line of a PV module with current-voltage characteristic curve of a PEM electrolyser by changing the series-parallel stacking configuration in both the PV module and electrolyser 11

12 Series parallel stacking of PV panels and PEM electrolysers PV array Electrolyser bank 12

13 Loss of energy and hydrogen production from different combinations PV- electrolyser combination Annual energy Annual energy loss Annual hydrogen PV module combination Electrolyser stack combination loss E kwh E % production (g)

14 Experimental Setup for PV Electrolyser Coupling Pyranometer PV Terminals Electrolyser Switch Box E 1 E 2 E 3 E 4 E 5 PV Panels Power Transducer Data Acquisition (DT 800) 14

15 Comparison of experimental and theoretical energy transfer and hydrogen production Total direct coupling time (hr:min) = 728:10 (December 2007-January 2008) Effective operation time of electrolysers (hr: min) = 466:50 Maximum potential total PV energy available (kwh) = Theoretical maximum potential total PV energy deliverable to the electrolysers (kwh) = Experimental total PV energy delivered to the electrolysers (kwh) = Difference between theoretical and experimental energy transfer (% of total energy delivered) = 4.95 Theoretical hydrogen production = g Experimental hydrogen production = g Difference between theoretical and experimental hydrogen production = 1.2% 15

16 Direct coupling of RMIT 2.4 kw PV array with CSIRO 2 kw PEM electrolyser 2.4 kw roof mounted PV array at RMIT Bundoora East 2 kw PEM Electrolyser (Oreion Alpha 1) 16

17 Optimal coupling of wind turbines and PEM electrolysers Dr Akraphon Janon 17

18 coupling of wind turbines and PEM electrolysers PEM electrolyser AIR 403 (400 W) Wind Turbine The best configuration, has a power transfer efficiency of between 94-99% within the wind speed range 6-12 m/s (total losses 34.3 kwh/year) Series-parallel configuration of individual cells to achieve the desired I-V characteristic Monitoring of cell degradation over a long period of time due to electrical input fluctuation Numerical simulation of I-V characteristic and power output Studying of generator coil layouts to achieve desired I- V characteristic that best matches the PEM electrolyser 18

19 Unitised Regenerative Fuel Cells Dr Arun Doddathimmaiah 19

20 A schematic of a unitised regenerative fuel cell system (URFC) Water in Power from solar/wind/other source H 2 O 2 Hydrogen Storage Charge cycle Discharge cycle URFC Charge cycle Discharge cycle Oxygen Storage H 2 O 2 Power out Water out 20

21 Round-trip energy efficiencies at maximum power input and output of experimental URFCs: one of the main challenges 45 R ound trip energ y effic ienc y (%) Dhar (1993) Swette et al (1994) Swette et al (1994) Swette et al (1994) Swette et al (1994) Ledjeff et al (1994) Mitlitsky et al (1998a) Mitlitsky et al (1998a) Mitlitsky et al (1998a) Mitlitsky et al (1998a) Zhigang et al (1999) Ioroi et al (2000) Ioroi et al (2001) Ioroi et al (2002) Ioroi et al (2002) Jorissen (2004) Yim et al (2004) Yim et al (2005) Wittstadt et al (2005) Song et al (2006) Other Technical Challenges: Design of bifunctional oxygen electrodes Extending lifetime Stack design URFC energy storage system design Lowering unit costs 21

22 New theoretical model of URFC Covers both electrolyser (E) and fuel cell (FC) mode operation Oxygen electrode j j O cell H cell j j O O H O O O O O 2F (1 )2F exp exp RT RT O O O O 2F (1 )2F exp exp RT RT 1 E FC j sat j sat O O jo jo Hydrogen electrode H H H H 2F (1 )2F exp exp RT RT H H H H 2F (1 )2F exp exp RT RT 1 E FC j sat j sat H H jo jo Additional terms based on logistic function to incorporate saturation effects at high current densities in both modes Use same equations for both modes by changing signs of overpotentials (η O and η H ) and hence current densities between modes 22

23 Voltage, [V] Experimental tests O2 side: IrO2-1 mg/cm2 H2 side: Pt - 2 mg/cm O2 side: IrO2-2 mg/cm2 H2 side: Pt - 2 mg/cm2 O2 side: Pt/IrO2-2 mg/cm2 H2 side: Pt - 2 mg/cm2 O2 side: Pt/IrO2-4 mg/cm2 H2 side: Pt - 4 mg/cm Current density, [A/cm 2 ] Measured URFC polarisation curves for MEAs with 2-4 mg/cm2 Pt loading on H-side and various catalyst loading on O-side 23

24 Performance evaluation of URFCs Energy efficiencies H 2 side catalyst and loading O 2 side catalyst and loading Electrolyser Efficiency Fuel cell Efficiency Round trip efficiency Ranking Pt mg/cm 2 Pt -0.4 mg/cm % 41.5% 29.6% 14 Pt - 2 mg/cm 2 Pt mg/cm % 41.2% 29.8% 12 Pt mg/cm 2 Pt -1 mg/cm % 43.2% 30.9% 11 Pt - 2 mg/cm 2 Pt - 1mg/cm % 43.2% 31.3% 10 Pt - 4 mg/cm 2 Pt - 1 mg/cm % 43.4% 32.9% 9 Pt - 2 mg/cm 2 Pt - 2 mg/cm % 46.3% 33.6% 8 Pt - 4 mg/cm 2 Pt - 2 mg/cm % 46.5% 35.4% 6 Pt - 4 mg/cm 2 Pt - 4 mg/cm % 48.5% 37.0% 5 Pt - 2 mg/cm 2 IrO 2-1 mg/cm % 32.3% 27.5% 17 Pt - 4 mg/cm 2 IrO 2-2 mg/cm % 33.2% 28.9% 16 Pt - 2 mg/cm 2 IrO 2 RuO 2-2 mg/cm % 35.2% 29.4% 15 Pt - 2 mg/cm 2 Pt/IrO 2 RuO 2-4 mg/cm % 44.8% 38.9% 4 Pt - 2 mg/cm 2 IrRuO x - 2 mg/cm % 36.2% 29.8% 13 Pt - 2 mg/cm 2 Pt/IrORuO x - 4 mg/cm % 46.3% 40.5% 2 Pt - 2 mg/cm 2 IrRu - 2 mg/cm % 31.0% 26.2% 18 Pt - 2 mg/cm 2 Pt/IrRu - 4 mg/cm % 42.3% 34.6% 7 Pt - 2 mg/cm 2 Pt/IrO 2-2 mg/cm % 45.5% 39.7% 3 Pt - 4 mg/cm 2 Pt/IrO 2-4 mg/cm % 46.5% 41.6% 1 Various measured energy efficiency values for the experimental URFCs. The ranking in the final column is in terms of roun-dtrip energy efficiency 24

25 Solar-hydrogen Combined Heat and Power (CHP) systems for remote area power supply Dr Bahman Shabani 25

26 Typical Sankey Diagram for the fuel cell 26

27 An Example to show the Fuel cell heat generation Theoretical analysis on a 500 W PEM BCS fuel cell hydrogen stoichiometry 1.2; air stoichiometry 2 ; inlet hydrogen pressure ~ 3-4 psi; exit air pressure 4 psi 27

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29 Computer Simulation Program RMIT Solar-Hydrogen Analysis Program (RSHAP) Mathematical models of the main components PV array: Diode-resistant model Fuel cell and Electrolyser: Modified Butler-Volmer equations Hydrogen Storage Tank: Low pressure conventional hydrogen tank 29

30 A case study using RSHAP Remote household in southeast Australia (family of two) Hourly solar radiation profile of Melbourne used as the typical profile for south-eastern Australia Daily electrical demand: 5 kwh Peak electrical demand: 0.3 kw Daily hot water consumption C A fuel cell stack based on the performance of a single cell of a 500 W BCS PEM fuel Cell An electrolyser stack based on the performance of a single cell of a 50 W StaXX7 electrolyser stack BP275 PV module 30

31 Fuel cell heat recovery to improve the round-trip energy efficiency of the energy storage sub-system Before heat recovery: Fuel cell efficiency= 999/2398= 41% Round-trip energy efficiency = 999/3323=30% After heat recovery: Fuel cell CHP efficiency= ( )/2398= 63% Round-trip energy efficiency = ( )/3323=45.5% 31

32 System optimisation by oversizing the fuel cell 32

33 System optimisation by oversizing the fuel cell 33

34 Experimental study Based on a 500 W water-cooled BCS PEM fuel cell 34

35 Fuel cell cooling load Fuel cell electrical and CHP energy efficiencies 35

36 Conference Papers: Publications 1- Mac E., Gray A., Webb C.J., Andrews J., Shabani B. et al., Hydrogen storage for off-grid power supply, 3rd International Symposium on Hydrogen in Matter Dec. 2009, Chennai, India 2- Shabani B., Andrews J., Badwal S.P.S., Theoretical and experimental investigation into using a PEM fuel cell to supply combined heat and power in a solar-hydrogen system, Sustainable Energy Technology Conference (SET 2009), 31 Aug.-3 Sept. 2009, Aachen, Germany 3- Shabani B., Andrews J., Badwal S.P.S., Fuel-cell heat recovery, electrical load management, and the economics of solar-hydrogen systems, 3rd IASTED, Asian Conference on power and energy systems, Oct. 2009, Beijing, China 4- Shabani B., Andrews J., Modelling of a solar-hydrogen combined heat and power system for remote power supply, 17th World Hydrogen Energy Conference (WHEC), June 2008, Brisbane, Australia 5- Paul, B & Andrews, J, 'Direct coupling of PV panels with PEM electrolysers in solar hydrogen systems: experimental performance analysis', paper presented to 17th World Hydrogen Energy Conference, Queensland, Australia, June Clarke, RC, Giddey, S, Ciacchi, FT, Badwal, SPS, Paul, B & Andrews, J, 'A stand-alone 2 kw PEM electrolyser integrated with a solar PV system for hydrogen generation', paper presented to 17th World Hydrogen Energy Conference, Queensland, Australia, June Paul, B & Andrews, J, 'Direct coupling of photovoltaic panels with PEM electrolyser in solar-hydrogen systems,' paper presented to Third IASTED Asian Conference on Power and Energy Systems, Phuket, Thailand, 2-4 April

37 Conference Papers: Publications 8- Doddathimmaiah, A & Andrews, J, 'Modelling and performance measurement of unitised regenerative fuel cells', paper presented to 17th World Hydrogen Energy Conference, Queensland, Australia, June Doddathimmaiah, A. and Andrews, J., The use of PEM unitised regenerative fuel cells in solar- hydrogen systems for remote area power supply, World Hydrogen Energy Conference, Lyon, France, June Andrews, J., Doddathimmaiah, A., Ali, S. and Akbarzadeh A, 'Solar hydrogen systems for remote area power supply from triple bottom line prospective', Proceedings of 2005 Solar World Congress - Bringing Water to the World, D. Y. Goswami et al. (ed.), American Solar Energy Society, Orlando, Florida 11- Doddathimmaiah, A.K., Andrews, J. and Akbarzadeh, A., Performance analysis of a proton exchange membrane unitised regenerative fuel cell for solar hydrogen systems for remote area power supply in ANZSES 2005 annual conference, Dunedin, New Zealand, November Janon, A & Andrews, J., 'Direct coupling of a fixed-pitch variable speed aerogenerator to PEM electrolysers in a wind hydrogen system for remote area power supply', paper presented to 17th World Hydrogen Energy Conference, Queensland, Australia, June Janon, A. and Andrews J., Modelling Small Wind-Hydrogen Energy Systems for Coastal Sites, ANZSES Solar 2006 Conference, Canberra

38 Journal Papers: Publications 1- Shabani B., J. Andrews, S. Watkins (2010) Energy and cost analysis of a solarhydrogen combined heat and power system for remote area power supply using a computer simulation. International Solar Energy Journal, 84 (1) E.MacA. Gray, C.J. Webb, J. Andrews, B. Shabani, P..J.Tsai, S.L.I. Chan (2010). Hydrogen storage for off-grid power supply International Journal of Hydrogen Energy, In Press Corrected Proof, Available online 16 October Shabani B., J. Andrews, S. Badwal (2010). Fuel-cell heat recovery, electrical load management, and the economics of solar-hydrogen systems. International Journal of Power and Energy Systems, 30 (4) (this paper was originally submitted to the 3rd IASTED conference in China 2009 and later was selected by IASTED to be published in this journal). 4- Shabani B., J. Andrews (2010). An experimental investigation of a PEM fuel cell to supply both heat and power in a solar-hydrogen RAPS system. International Journal of Hydrogen Energy, under review. 5- Paul B. and J. Andrews (2008). Optimal coupling of PV arrays to PEM electrolysers in solar-hydrogen systems for remote area power supply. International Journal of Hydrogen Energy 33(2): Clarke R. E., S. Giddey, F. T. Ciacchi, S. P. S. Badwal, B. Paul and J. Andrews (2009). Direct coupling of an electrolyser to a solar PV system for generating hydrogen. International Journal of Hydrogen Energy 34: Doddathimmaiah A. and J. Andrews (2009). "Theory, modeling, and performance measurement of unitised regenerative fuel cells." International Journal of Hydrogen Energy 34(19):

39 Ongoing and Future Work Need for complete demonstration of a solar-hydrogen system in a suitable remote application R&D into MH storages for solar/wind-hydrogen energy systems Control system for solar-hydrogen system Many opportunities for commercial take-up of developed to date by Australian and/or international companies come and talk to us! 39

40 Some of the key findings from the case study Solar-hydrogen CHP system 40

41 Some of the key findings from the case study Solar-hydrogen CHP system 41