This document discusses specifications for solid oxide electrolysis stacks to be coupled with wind turbines or nuclear power. It provides an overview of a workshop on high temperature water electrolysis limiting factors held in Karlsruhe, Germany in June 2009. The document discusses the potential for high temperature steam electrolysis to produce hydrogen using excess electricity from wind power or nuclear power. It examines considerations for solid oxide electrolysis stack specifications including operating temperature, degradation rate, operating profile, current density, and cell voltage.

2. International Workshop on high temperature
water electrolysis limiting factors
Specifications for
Solid Oxide Electrolysis Stacks
to be coupled with
Wind Turbines or
Nuclear Power
Thomas Nietsch / Helion
John Boegild Hansen / Haldor Topsoe
Karlsruhe/Germany, 9&10 June 2009
HELION

3. Overview
1. Introduction
Areva – Helion
Haldor Topsoe
2. Introduction
High temperature steam electrolysis
3. The wind case
4. The nuclear case
5. Summary
3 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 3

4. Introduction
Areva – Helion
Haldor Topsoe
HELION

5. An integrated offer serving energy professionals
5 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 5

6. HELION – an AREVA R Subsidiary
Wind power Bioenergies Hydrogen power
Biomass power plant Fuel cell & electrolyser
Offshore wind energy design & integration
business based systems
MULTIBRID KOBLITZ HELION
6 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 6

7. HELION Hydrogen Power – Key figures
A R&D oriented company specialized in hydrogen energy and fuel cells
moving towards an industrial company, profitable on its early niche
markets
Founded in 2001, HELION designs,
manufactures and integrates PEM
fuel cell and electrolysis solutions
A strong R&D backbone in
electrochemistry and engineering
Headcount: more than 50
employees
75% engineers
Headquarter : Aix-en-Provence
(France)
( Environment dedicated high-tech
facilities complex )
7 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 7

8. HELION Hydrogen Power
HELION develops PEM Fuel Cell and Electrolyser for:
Backup power applications
Niche transport applications Hydrogen production
Air-independent applications Energy storage
8 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 8

9. Briefly on Topsoe Fuel Cell
Development, manufacturing, marketing
and sales of SOFC technology
Founded in 2004
Subsidiary of Haldor Topsøe A/S (wholly
owned)
SOFC research & development since
1989
Employees: 100+
Strategic research partnership with Risø
DTU (National Laboratory for
Sustainable Energy)
>50 empl. engaged in SOFC
9 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 9

10. Introduction
High temperature steam electrolysis
HELION

11. SOEC more efficient than present Electrolysers
5,0
theoretical and real energy imput to electrolyser
4,5
real PEM E
4,0 system
"real" SOEC
theoretical stack total enery demand system
3,5
= heat demand + electrical energy demand: Δhr
H2
3
Energy E/kwh/m
3,0
2,5
theoretical stack electrical energy demand: Δgr
2,0
steam
1,5
liquid water
1,0
theoretical stack heat demand: TΔsr
0,5
p = 1 bar
0,0
0 100 200 300 400 500 600 700 800 900 1000
Temperature T/°C
11 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 11

12. Results from Hi2H2 project, a pre assessor of
RelHy
12 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 12

13. RelHY Project – 2.9 M€ Support
from EU 7th framework program
Goals
Participants 1 A/cm2
CEA, F Steam utilsation > 60 %
DTU Risø, DK 800 °C
ECN, NL System efficiency = 80 %
Imperial College, UK Degradation < 1 %/1000 h
Topsoe Fuel Cell, DK Availability = 99 %
Eiffer (EDF), F
Helion (Arreva), F
13 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 13

14. RelHy Project Overview
RelHy Integration of
25-cell stack optimised materials and
prototype, innovative design in a
operated at reliable and efficient
800°C laboratory electrolyser
prototype
d
te
en
um 5-cell
tr
I ns Stacks
Design innovations
Thermo mechanics, Tightness,
SRUs Water management
State of the Art
• Good cells Cells Materials optimisation
• No compromise Durable electrodes/electrolyte, Sealing,
Material compatibility and stability,
in stacks nor SRUs
Cost effective materials and processes
between durability
and efficiency
14 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 14

15. Technical challenges: generic roadmap
From electrolysis »Cell efficiency + durability
technology… (electrolyte conductivity,
catalysts efficiency, stability vs corrosion)
Material knowledge
»Stack efficiency
(fluids, heat, mass transfer management,
Mechanical assembly, Gas tight conception)
Thermomechanical, thermohydraulic,
gasketing and assembly knowledge
»Module architecture
(stack association, process management )
Electrochemical and
thermodynamical
processes knowledge
»Plant definition
(module association, process management )
… to H2 production plant Plant process, regulation
and safety knowledge
15 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 15

16. The wind case
HELION

17. Wind Power Production - West Denmark
As percent of consumption and production
Averages 26 and 24 %
140%
% of Production
% of Consumption
120%
100%
W ind power %
80%
60%
40%
20%
0%
0 1000 2000 3000 4000 5000 6000 7000 8000 9000
Hours of 2007
17 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 17

18. Electricity spot price – West Denmark
Diurnal Variations - 2007
200
180
160
140
120
€/MWh
100
80
60
40
20
0
0 2 4 6 8 10 12 14 16 18 20 22 24
Hours no 2007
18 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 18

19. Average spot COE price as function of operating hours
West Denmark 2007
35
30
25
20
€/MWh
15
10
5
0
0 1000 2000 3000 4000 5000 6000 7000 8000 9000
Operating Hours
19 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 19

20. Depreciation cost vs operating hours/yr
750 €/kW – 10 years depreciation
100
90
80
70
60
€/MWh
50
40
30
20
10
0
0 1000 2000 3000 4000 5000 6000 7000 8000 9000
Hours no 2007
20 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 20

21. Cost of Hydrogen
Investment 750 €/kW + average spot COE price 35 €/MWh
0,25
0,20
2 US $/kg
0,15
€/Nm3 H2
0,10
1.55 V
1.9 V
0,05
70 €/kWh => 3.x US$/kg
0,00
0 1000 2000 3000 4000 5000 6000 7000 8000 9000
Hours of operation per year
21 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 21

22. HTSE with wind power in Denmark
(Cheap CO2 free) electricity from wind
Heat from existing CHP plants / district heating
From biomass using oxygen for increasing the efficiency
and easier CO2 sequestration
Complex system
Energy management is crucial
22 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 22

23. Active Power Control valuable in Wind Scenario
Consumer's Electrolyser’s Wind mils answer
power demand answer
Increases Decrease Load Increase generation
Fast Response ? Only possible in
special cases with
prior reduction
Decreases Increase Load Decrease
Generation
Slow Response
Fast response
< 5 seconds
23 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 23

24. The nuclear case
HELION

25. Current density
1 000 000
200 t/day H2
The figure gives an example
3,8 kWh/m3
26 petrol stations
for the number of cells vs
800 000
current density with active
area as parameter.
total number of cells
600 000
S_A
This figure illustrates nicely
100 cm²
400 000 that a reasonable reduction
200 cm² of number of cells can be
200 000 400 cm² achieved for an active area
1 000 cm² 800 cm² 600 cm²
around 600 cm² and around
0 a current density of 2 A/cm².
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0
current density j A/cm²
25 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 25

26. Operating temperature
The steam temperature of a Evolutionary Pressurised Nuclear
Reactor (EPR) is some what near 300 °C.
The sate of the art operating temperature for SOFCs is some
what around 850 °C, therefore this temperature is considered
as starting or reference temperature.
Operating temperature reduction in the future is proposed for:
Better match the nuclear reactors outlet temperature so higher
efficiency
Easier and more efficient heat transport
Using cheaper materials and
(Lower the degradation rate).
(The steam temperatures of a High Temperature Nuclear
Reactor (HTR) or a Very High Temperature Reactor (VHTR) can
be higher than 800 °C.)
26 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 26

27. Degradation / life time
There is no definition for life time or for end of life
neither for SOFC nor SOEC.
A commonly proposed criterion for end of life is a loss
in performance of 20 %.
Assuming a life time of about 40 000 h for achieving
cost targets in the SOFC case give a degradation rate of
about 5 to 10 µV/h.
SOFC targets are chosen as a starting point
27 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 27

28. Operating profile
Coupled with nuclear Coupled with RES (wind).
power. Stochastic energy
Flat out production during production by RES but
a long period of time, smoothened by thermal
possibly a year or longer. capacity of the stack.
Start up time can be one Start up time about one
working shift. hour.
A very few start ups, shut Some more thermal / redox
downs and redox cycles cycles required.
during life time are
required.
28 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 28

29. Cell voltage
Efficiency, energy consumption and cell voltage are
closely related.
Modern PEM and alkaline electrolyser systems are
aiming for efficiencies of about 75 % and 80 %
respectively or about 1,6 V. (Ref: fuel cells and hydrogen joint undertaking (FCH JU),
annual implementation plan 2008 )
A HTSE should aim for higher efficiency to compensate
for possible higher capital cost.
Assuming an 85 % efficient HTSE gives a stack voltage
around 1,47 V.
241 KJ/mol/2/(96500As/mol)/0,85 = 1,47 V
29 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 29

30. Example: sketch of HTSE coupled with a
pressurized water reactor,
heat extraction at 280 °C from the boiler
Remark: the boiler could be fired by biomass
30 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 30

31. Example: sketch of HTSE coupled with a
pressurized water reactor,
heat extraction at 180 °C from HP turbine outlet
Remark: the boiler could be fired by biomass
31 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 31

32. Deployment for HTSE plant
EPRTM use in a
cogeneration mode:
Production targeted: 500 t/d
of H2
Electrical Input: 720 MW
Thermal Energy extracted:
140 MW at 240°C
32 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 32

33. 33 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 33

34. Summary
HELION

35. Differences Nuclear/Wind Scenario
RelHY milestone delivered in January
Nuclear Wind
Short Medium Short Medium
Degradation (µ/h) 10 5 15 5
Lifetime (h) 10000 20000 16000 40000
Thermal cycles/year 2 5 7 14
Voltage/cell (V) 1.5 1.45 1.7 1.55
Current (A/cm2) 1.5 2.0 1.0 1.5
Pressure max (bar) 50 50 20 30
Active Area (cm2) 400 800 300 600
Start up from 600 C <4h < 4h <2 < 1h
Turn down to 20 % ? ? < 2 min. < 30 sec.
35 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 35

36. HELION

37. References
(1) JP Py and A. Capiyaine, Hydrogen production by high temperature
electrolysis of water vapor and nuclear reactors, WHEC 2006, Lyon
(2) Hering, INL, NEA, 3rd IEM, 5 Oct 05
(3) Hotely 1982, US Department for Commerce, NTIS
(4) M. Zahid, high efficient, high temperature hydrogen production by
water electrolysis, Hi2H2, hydrogen and fuel cells review days 2007,
Brussels, 10th & 11th October
37 HELION > Int Workshop on HTWE Specifications for SOE Stacks, Karlsruhe, June 09 T. Nietsch, J.B. Hansen Helion 23983 37