Your Heart of Energy
staxera is committed to supplying the highest
quality SOFC stacks in the world, with excellent customer service. Please do not hesitate
to contact us for further information.
staxera GmbH 2010
staxera GmbH
Gasanstaltstraße 2
01237 Dresden . Germany
phone:
+49-351-896797-0
fax:
+49-351-896797-831
info@staxera.de
www.staxera.de
staxera GmbH | Gasanstaltstraße 2 | 01237 Dresden . Germany | phone: +49-351-896797-0 | www.staxera.de
SOFC Stack Modules for Decentralized Power Generation
Your Heart of Energy
Customers around the world are demanding
services at lower cost and with less environmental impact. Electricity generation based
on high efficiency solid oxide fuel cells
(SOFC) is best able to meet this need.
The main barrier to market entry has been,
until now, the supply of a robust and stable
SOFC stack.
staxera has solved this problem and now
offers its integrated stack module (ISM) in
volume and at low cost. The ISM is the heart
of any SOFC energy conversion system.
This product provides staxera’s customers
with the opportunity to develop SOFC systems and then to enter and dominate the
market for decentralized power generation.
staxera is the world leading supplier of solid
oxide fuel cells for SOFC systems – the only
supplier with the staxera advantage.
Ready to deliver
Security of supply
staxera’s SOFC integrated stack modules (ISMs) are available immediately in
volumes of up to 500 units per year. Standardized ISMs can be supplied for
initial system development and customized ISMs can be developed to allow even
tighter system integration. High volume manufacture (up to 50.000 units per
year) is possible within two years, allowing for the construction of a new manufacturing hall, installation of automated assembly equipment, and commissioning.
n
active in more than 58 countries
n
automobile component supplier
n
1.6 billion € turnover in 2008
n
7.5% investment of turnover in R&D
n
more than 7000 employees
staxera GmbH is stably and securely held by Webasto AG, a German family
owned company and one of the world’s 100 largest automobile component
suppliers.
staxera was previously a 50:50 joint venture between Webasto AG and H.C. Starck. Webasto AG obtained full
control of staxera by purchasing H.C. Starck’s
50 % shareholding in late 2009. H.C. Starck
remains staxera’s cell supplier and development partner. Webasto AG and staxera
GmbH are committed to the long term
development of SOFC as a key component in the world’s clean tech future.
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Mk200 SOFC stack
The staxera Mk200 stack was developed using a top-down design process based
on clear system requirements for low cost, low pressure drop and robust operation.
Stamped sheet metal interconnects provide low cost while ESC cells provide thermal and redox stability.
The stack is compatible with a wide variety of fuel
gases, including CPOX and steam reforming. Air
flow can be either co-flow or counter-flow, simply by
selecting which side to use as the air inlet.
staxera has developed a deep understanding of the
temperature gradients and thermomechanics occuring within the Mk200 stack. This enables us to optimize the design and deliver world-class robustness
and endurance.
Low anode and cathode pressure drops help to minimize system parasitic losses, while an open cathode allows tight system integration if desired.
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Integrated stack module (ISM)
The staxera ISM provides the critical functional environment for the SOFC stack, thereby allowing
rapid system integration and robust performance.
Clearly defined interfaces for gases, sensors and
electrical current are provided, as well as components for compression loading, thermal insulation,
cathode manifolding; and pressure, voltage and
temperature measurement.
Using this approach staxera guarantees 5.000 hours
of operation and 20 thermal cycles when the ISM is
operated within pre-defined parameters.
The ISM is presently available with a rated power of
1.1 kW at a fuel utilization of 75%. Future ISMs will
have increased power, reduced heat loss, and higher
limits for fuel utilization.
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Your heart of energy
Continuous improvement
staxera delivers ISMs worldwide to a large variety of industrial customers,
staxera has been developing SOFC stacks since the company was founded in
supporting individual requirements whilst maintaining complete confiden-
2005. Products have been sold on the open market since 2006, when the
tiality. The ISM forms the heart of each customer's energy conversion sys-
Mk100 stack was first introduced. Each year thereafter has seen continuous
tem. Several of staxera’s customers are shown here.
improvement in staxera’s products, including the higher power Mk200 stack in
2007 and the integrated stack module (ISM) in 2008.
EBZ GmbH has developed a 3 kW system demonstrator based on
steam reforming of natural gas. This system can be modified to suit
The ISM is now staxera’s main product, owing to its defined interfaces and ease
a range of fuels such as biogas and landfill gas; and is also capable
of use. Since 2009 staxera’s has supplied large customers with customized
of acting as a combined heat and power (CHP) system. The system
ISM designs, according their individual requirements.
is available for purchase – please contact www.ebz-dresden.de for further details.
Vaillant GmbH is one of
Europe’s largest manufacturers of heating, ventilation and air conditioning
systems. Vaillant is developing a 1 kW microCHP
system for single family houses. Vaillant selected the
staxera SOFC as it's basis for a microCHP system
2006
2007
2008
2010
over competing technologies such as stirling engines,
PEM fuel cells and internal combustion engines.
Year
Company improvement
Callux is Germany’s big-
2005
Company founded
gest practical test project
2006
Mk100 stack, 350 W
for small residential fuel cell based heating systems.
2007
Mk200 stack, 500 W
As part of the National Innovation Program for Hy-
2008
Integrated stack module (ISM), 1 kW
drogen and Fuel Cell Technology (NIP), industry and
2009
ISM 1.1 kW, customer specific solutions
government are together investing 1 billion € to
2010
ISM 1.4 kW
promote this innovative concept. More than 50 fuel
2011
ISM 1.7 kW
cell heaters are already up and running, and by the
2012
ISM
3 kW
end of 2012 some 800 units will undergo trials.
2013
ISM
5 kW
www.callux.net
A significant number of these units will be constructed by Vaillant using ISMs from staxera.
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staxera advantage
SOFC system developers can save time and reduce cost and risk by sourcing ISMs from staxera. This
produces the best possible business case for the SOFC developer – the staxera advantage.
Time to market
The ISM is available immediately in volumes of up to 500 units per year. Standardized ISMs can be supplied
staxera’s expertise is SOFC stack engineering de-
for initial system development, and customized ISMs can be developed to allow even tighter system inte-
sign and manufacture, focussing on thermomechanics,
gration. High volume manufacture (up to 50.000 units per year) is possible within two years, allowing for
tolerances and scale up.
the construction of a new manufacturing hall.
Development cost and production cost
Sourcing ISMs from staxera is cheaper than either developing a new SOFC stack design or manufacturing
Fraunhofer IKTS is staxera’s R&D partner, focus-
at a separate facility. staxera has already developed the stack, together with a family of proprietary and pa-
sing on materials science, sealing glasses, contact
tented production processes. SOFC production costs are strongly dependent upon production volume,
pastes and protective coatings.
and our customers benefit from staxera’s quantity of scale. In series production the profit margins from
staxera will be comparable with suppliers from the automotive industry.
Backup by broad R&D support
staxera’s technical results are backed by a multi-year joint research program between the Fraunhofer IKTS
H.C. Starck is staxera’s cell, paste, and glass sup-
and staxera. IKTS is investigating the degradation mechanisms of interconnector steels, contact elements
plier; with a manufacturing capacity of 3 million cells
and sealing glasses, and the results of this work will lead to a new generation of materials and therefore to
per year.
improved stack performance. This deep understanding of failure mechanisms substantially reduces our customer’s long term development risk.
Technical risk
The optimum performance of SOFC stacks in a system environment requires specific stack characteris-
ThyssenKrupp VDM is staxera’s supplier for high
tics. These are not obvious if you start with a bottom up stack development program from cells to stacks.
temperature ferritic sheet steel, optimized for SOFC
staxera has manufactured and tested hundreds of stacks; has conducted an initial HAZOP analysis; and
operation.
has improved the design accordingly.
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Technical performance
ISMs from staxera have excellent technical performance in the critical areas of power, thermal cycling,
lifetime and redox stability. These parameters are absolutely crucial for successful system performance.
Power
The staxera SOFC stack delivers both high power and high efficiency, owing to
it’s capacity to operate at 75% fuel utilization.
Thermal cycling
staxera has demonstrated 150 thermal cycles with a 30-cell Mk200 stack, and
50 thermal cycles with a ISM. This is world class performance.
Lifetime
staxera has demonstrated over 10.000 hours of stable operation on both the older
Mk100 and the present Mk200 stack designs, with degradation less than 0.4%
per 1.000 hours. Commercial targets are between 40.000 and 80.000 hours.
Redox stability
ESCs have excellent redox stability as the anode (which expands and contracts
as it oxidizes and reduces) is very thin, and is supported by the thicker electrolyte.
The power delivered by a staxera ISM is dependent upon the fuel composition, fuel utilization and the
operating temperature. To improve our customer service staxera has selected one reference operating
condition which all organizations can reproduce:
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fuel composition of 40% hydrogen and 60% nitrogen
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fuel utilization of 75%
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operating temperature 850°C
The diagram above shows the power as a function of current at the reference operating condition, and
also at two other typical gas compositions.
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SOFC stacks must be able to operate reliably and stably over a long period of time. For typical
SOFC stacks must be able to turn on and off with the SOFC system. This is called thermal cycling,
applications such as microCHP or decentralized power generation, our customers require a life-
and the number of cycles required is dependent upon each customer and each system application. The
time of at least 40.000 hours, with some customers requiring 80.000 hours. The degradation
diagram above shows that the Mk200 stack can survive over 160 complete power and thermal cycles.
over this time period must usually be less than 0.5% per 1.000 hours.
The stack cycles between 850°C and 100°C, and also between full load (22 A) and no load. This is
world class performance.
staxera has conducted endurance tests of over 10.000 hours with both the older Mk100 stack design
and the present Mk200 stack design. The diagram above shows that the total stack degradation after
12.000 hours is less than 4%, which translates to less than 0.4% per 1.000 hours.
Since this data was collected staxera has improved the cycling capability of the Mk200 stack, which
should prevent sharp changes in degradation as observed at 7.500 hours above. Until this time, the
stack had a total degradation of less than 0.1% per 1.000 hours.
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3 kW system demonstrator
The 3 kW system demonstrator is a product from the
company EBZ GmbH, which is also located in Dresden, Germany. EBZ and staxera cooperated on the
development of this system.
The system was developed to show that the staxera
ISM can operate reliably and efficienctly when fuelled
with steam reformate, particularly with internal reforming. Secondly, the system is intended as the first
step towards 20 kW systems for decentralized electricity generation.
The 3 kW system demonstrator is designed for a peak
stack power of 3 kW, using two staxera ISMs, each
with a peak power of up to 1.5 kW. At present the
system is operating with two 1.1 kW ISMs. Future
systems will have a power output of 5 kW and then
The 3 kW system demonstrator is the ideal platform for SOFC system research
20 kW. staxera and EBZ are seeking an industrial
and development. Control strategies can be adjusted and some components
partner for this project.
(such as ISM, blowers) can be exchanged.
Customized solutions
The system is able to be modified to suit each customer’s individual requirements. For example, for operation with biogas or LPG, or with power levels from
1 to 5 kW. For more details please contact EBZ directly: www.ebz-dresden.de
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Your Heart of Energy
staxera is committed to supplying the highest
quality SOFC stacks in the world, with excellent customer service. Please do not hesitate
to contact us for further information.
staxera GmbH 2010
staxera GmbH
Gasanstaltstraße 2
01237 Dresden . Germany
phone:
+49-351-896797-0
fax:
+49-351-896797-831
info@staxera.de
www.staxera.de
Your Heart of Energy
staxera is committed to supplying the highest
quality SOFC stacks in the world, with excellent customer service. Please do not hesitate
to contact us for further information.
staxera GmbH 2010
staxera GmbH
Gasanstaltstraße 2
01237 Dresden . Germany
phone:
+49-351-896797-0
fax:
+49-351-896797-831
info@staxera.de
www.staxera.de
staxera GmbH | Gasanstaltstraße 2 | 01237 Dresden . Germany | phone: +49-351-896797-0 | www.staxera.de
SOFC Stack Modules for Decentralized Power Generation