Stack Module Research Articles

Experimental Analysis of a 25 kWe Solid Oxide Fuel Cell Module for Co-Generation of Hydrogen and Power

The hydrogen refueling station infrastructure is a critical bottleneck that should be addressed for the penetration of the fuel cell vehicles in the automotive sector. The EU co-funded project, “Co-generation of hydrogen, heat and power (CH2P)”, aims to address this by developing a prototype for onsite hydrogen generation from methane rich gas using Solid Oxide Fuel Cells (SOFC). The prototype system will produce 25 kWe electric power and 20 kg of H2/day. It consists of a large SOFC stack module along with necessary balance of plant components. An experimental analysis on the 25 kWe SOFC module is performed to aid the development of the prototype system. The study focuses on understanding the electrochemical performance of the stack towers within the stack module, thermal behavior, such as the temperature distribution among the stack towers and heat losses, and pressure drops

Operation of an SOFC CHP System with Wood Gas from a Fixed-Bed Updraft Gasifier

This paper will show the results of operating an SOFC system with the product gas from a biomass gasifier for more than 200 hours under constant and dynamic operation. The SOFC system was operated at different load cases, 50 % and 100 % load, and achieved a gross electrical efficiency of 42 %. It shows a high dynamic behavior, so that electric load changes could be performed within a few seconds from full load to part load. Furthermore, AVL developed a simulation software by which a SOFC stack model can be simulated dynamically. A comparison of the measured and simulated values of the stack module will be presented. By using the results of the test runs the software could be validated successfully.

Analysis of Internal Gas Leaks in an MCFC System Package for an LNG-Fueled Ship

The airflow inside the housing of a 300-kW molten carbonate fuel cell (MCFC) system is designed to ensure safety in case of a gas leak by applying computational fluid dynamics (CFD) techniques. In particular, gas accumulating zones are identified to prevent damage to vulnerable components from high temperature and pressure. Furthermore, the location of the alarm unit with the gas-leak detector is recommended for construction of safe MCFC ships. In order to achieve this, a flow-tracking and contour field (for gas, temperature, and pressure) including a fuel-cell stack module, balance-of-plant, and various pipes is developed. With the simulated flow field, temperature flow is interpreted for the heating conditions of each component or pipe in order to find out where the temperature is concentrated inside the fuel cell system, as well as the increase in temperature at the exit. In addition, the gas leakage from the valves is investigated by using a flow simulation to analyze the gas and pressure distribution inside the fuel cell system.

Effect of Mechanical Stress Factors on Large Format Li-Ion Cell Thermal Runaway Characteristics

Expansion and contraction of Li-ion cell electrodes during cycling is known to exert mechanical stress and strain within cell components. During cell charge, Li-ion intercalation into the graphite anode structure increases anode swelling and thickness. Upon cell discharge, Li-ions de-intercalate from the carbon anode structure causing cell-level relaxation and a proportional reduction in cell swelling. Li-ion cell swelling has been shown to be a function of cell discharge rate, state-of-charge (SoC), and age. The impact of mechanical stress-strain swelling on Li-ion cells creates high contact pressure between electrode layers, degrades conductive carbon particle contact resistance, and irreversibly deforms the cell case structure. Mechanical stress loading also causes fatigue within internal cell components leading to an increase in cell impedance and capacity loss which may reduce cell cycle life performance. Li-ion battery (LIB) manufacturers have long recognized that the effects of cell-stack level stress fatigue on battery module architectures must be considered in LIB packaging designs requiring long cycle life performance. In LIB designs utilizing prismatic or elliptical-cylindrical cell geometries, cells are commonly packaged into modules by restraining the module stack by compression loading. In this manner, the adverse effects of cell stack deformation during charge-discharge cycling can be mitigated. In space applications, compression loading of cell modules also enables LIB’s to survive launch vehicle shock and vibration environments at high SoC’s. More importantly, mechanical abuse of LIB’s can result in an energetic catastrophic failure event. At high SoC’s, the hazards of a LIB safety incident may include venting, smoke, and fire indicative of catastrophic thermal runaway. Recently, the NASA has investigated the severity and consequences of catastrophic thermal runaway of large format Li-ion cell-based LIBs for human space flight applications. Thermal runaway safety testing of certain space-qualified Li-ion cell designs has shown that there is a correlation between applied cell compression forces and thermal runaway severity. This work focuses on the relationship between compression force and SoC on large format Li-ion cells qualified for human space flight applications. Empirical results from simulated internal short circuit trigger testing designed to induce catastrophic thermal runaway will be discussed.

Numerical analysis of an SOFC stack under loss of oxidant related fault conditions using a dynamic non-adiabatic model

This paper presents a numerical analysis of a 1000 W-class solid oxide fuel cell stack. The study includes simulation of dynamic operation of the unit under conditions which are qualified as faults. The simulation tool was developed to address the effects of oxidant-related faults on the operating parameters of the stack. Additionally, a control system was proposed in order to mitigate the effects of the sudden reduction in the flow of oxidant and passivation of the cells inside a 60-cell stack. In the current study, those occurrences were related to the loss of tightness of the sealants in the stack of planar cells. The model of an adiabatic-stack was used to generate the temperature profiles and was used in two reference cases. In the first case, the control system was activated in order to maintain the key parameters within the safe range, in the second case the simulations with deactivated controls enabled prediction of the temperature, voltage and power in the stack which continues operation without counteractions oriented toward minimizing the negative impacts on the performance due to exceeding the given limiting values of parameters. In the current study, two scenarios were analyzed: partial loss of oxidant and partial failure of stack modules resulting in decrease of the generated electric power. The results of both cases are presented, with and without the fault prevention control modules considered. Adjustment of the operating parameters can effectively limit the rapid increase in thermal gradients inside the stack. To complement the discussion, a classification of the typical faults of SOFC stack is presented.

Practical bioinstrumentation developments for AC magnetic field-mediated magnetic nanoparticle heating applications

Heat dissipation during magnetization reversal processes in magnetic nanoparticles (MNP), upon exposure to alternating magnetic fields (AMF), has been extensively studied in relation to applications in magnetic fluid hyperthermia (MFH). This current paper demonstrates the design, fabrication, and evaluation of three innovative advances in bioinstrumentation research, operating on this principle, for use as (i) a non-contact, in vitro, real-time temperature monitor; (ii) a drug release analysis system (DRAS); and (iii) a high flux density module for AMF-mediated MNP studies. The proposed DRAS is demonstrated by an AMF-mediated drug-release proof-of-principle experiment. Also, the technique described facilitates non-contact temperature measurements of specific absorption rate (SAR) as accurately as temperature measurements using a probe in contact with the sample. Numerical calculations estimating the absolute and root mean squared flux densities, and other MNP—AMF studies suggest that the proposed stacked planar coil module could be employed for calorimetry.

Improving Electrochemical Activity in a Semi-V-I Redox Flow Battery by Using a C–TiO2–Pd Composite Electrode

This study developed composite electrodes used in a semi-vanadium/iodine redox flow battery (semi-V-I RFB) system and designed semi-V-I RFB stacks to provide performance comparable to that of an all-vanadium redox flow battery (all-VRFB) system. These electrodes were modified using the electroless plating method and sol-gel process. The basic characteristics of the composited electrodes, such as the surface structural morphology, metal crystal phases, and electrochemical properties, were verified through cyclic voltammetry, field emission-scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray diffraction. The results show that the sintering C–TiO2–Pd electrode improved the electrocatalytic activity of the semi-V-I RFB system, thereby effectively increasing the energy storage ability of the system. The C–TiO2–Pd electrode was used as a negative electrode in a single semi-V-I RFB and exhibited excellent cyclic performance in a charge-discharge test of 50 cycles. The average values for coulomb efficiency, voltage efficiency, and energy efficiency were approximately 96.56%, 84.12%, and 81.23%, respectively. Moreover, the semi-V-I RFB stacks were designed using series or parallel combination methods that can effectively provide the desired operating voltage and linearly increase the power capacity. The amount of vanadium salt required to fabricate the semi-V-I RFB system can be reduced by combining large stack modules of the system. Therefore, this system not only reduced costs but also exhibited potential for applications in energy storage systems.

System Level Exergy Assessment of Strategies Deployed for Solid Oxide Fuel Cell Stack Temperature Regulation and Thermal Gradient Reduction

Several operational strategies for solid oxide fuel cell (SOFC) temperature regulation and temperature gradient minimization at cell scale have previously been assessed by the authors (Amiri et al., Ind. Eng. Chem. Res., 2016). The application of such strategies at system scale, however, requires a numerical linkage between the cell and the system performance metrics allowing simultaneous evaluation of the dominant process interactions. The objective of this study is to analytically examine the effectiveness and applicability of the mentioned thermal management methods at system scale. To achieve this, a system level exergy analysis is presented by using a modeling platform in which a detailed four-cell short stack module and the balance-of-plant (BoP) are integrated. Linkage between the system performance metrics and the stack internal temperature gradient is specifically emphasized. For this, the exergy intensive points (unit operations) are identified throughout the plant. Subsequently, the effective strategies that had been employed for the cell level thermal management proposed in our previous work (Amiri et al., Ind. Eng. Chem. Res., 2016) are examined at the system level capturing the effects on the state of BoP exergy intensive components. Moreover, fuel design is proposed and evaluated as a potential thermal management strategy. Combination of a variety of measures including the exergy destruction rates, the electrical and thermal efficiencies, and the stack internal temperature gradient provides a comprehensive set of data contributing to the SOFC system thermal management.

Design and Implementation of a Compact 3-D Stacked RF Front-End Module for Micro Base Station

In the current 4G Long Term Evolution and the incoming 5G mobile communication technology, as the number of radio frequency (RF) devices in the RF front-end module is increasing fast, miniaturization is essential and significant. The 3-D RF system-in-package (SiP) technology is an excellent miniaturization solution. In this paper, a 700–2900-MHz 3-D stacked RF module with the size of 23 mm $\times$ 23 mm $\times$ 3.3 mm has been designed and implemented, which is used for a micro base station. It is more compact than other reported 3-D RF SiP products used for micro base stations. The 3-D RF module integrates four bare dies, one quad flat no-lead packaged chip, and more than 200 passive devices. Considering the electromagnetic isolation requirement, mechanical performance, and effective interconnection, the detailed structure design is presented in this paper. Simulations are performed for the electrical characterization and the thermal performance evaluation of the stacked module. The simulation results show that the insertion loss ( $S_{21}$ ) and return loss ( $S_{11}$ ) of the RF signal transmission lines are controlled below 0.42 dB and over 15 dB within 3 GHz, respectively. The electromagnetic isolation between different RF and/or intermediate frequency signal transmission lines is no less than 65 dB within 3 GHz. In thermal management simulation, the highest junction temperature of the chips in the 3-D structure is below 94 °C at the severe condition (50 °C ambient temperature and nature air convection). Finally, the assembly flow is presented, and the test results indicate the good electrical performance of the 3-D RF module.

Perovskite Photovoltaic Modules: Life Cycle Assessment of Pre-industrial Production Process

SummaryPhotovoltaic devices based on perovskite materials have a great potential to become an exceptional source of energy while preserving the environment. However, to enter the global market, they require further development to achieve the necessary performance requirements. The environmental performance of a pre-industrial process of production of a large-area carbon stack perovskite module is analyzed in this work through life cycle assessment (LCA). From the pre-industrial process an ideal process is simulated to establish a benchmark for pre-industrial and laboratory-scale processes. Perovskite is shown to be the most harmful layer of the carbon stack module because of the energy consumed in the preparation and annealing of the precursor solution, and not because of its Pb content. This work stresses the necessity of decreasing energy consumption during module preparation as the most effective way to reduce environmental impacts of perovskite solar cells.

Effect of the Electron Transport Layer on the Interfacial Energy Barriers and Lifetime of R2R Printed Organic Solar Cell Modules.

Understanding the phenomena at interfaces is crucial for producing efficient and stable flexible organic solar cell modules. Minimized energy barriers enable efficient charge transfer, and good adhesion allows mechanical and environmental stability and thus increased lifetime. We utilize here the inverted organic solar module stack and standard photoactive materials (a blend of poly(3-hexylthiophene) and [6,6]-phenyl C61 butyric acid methyl ester) to study the interfaces in a pilot scale large-area roll-to-roll (R2R) process. The results show that the adhesion and work function of the zinc oxide nanoparticle based electron transport layer can be controlled in the R2R process, which allows optimization of performance and lifetime. Plasma treatment of zinc oxide (ZnO) nanoparticles and encapsulation-induced oxygen trapping will increase the absolute value of the ZnO work function, resulting in energy barriers and an S-shaped IV curve. However, light soaking will decrease the zinc oxide work function close to the original value and the S-shape can be recovered, leading to power conversion efficiencies above 3%. We present also an electrical simulation, which supports the results. Finally, we study the effect of plasma treatment in more detail and show that we can effectively remove the organic ligands around the ZnO nanoparticles from the printed layer in a R2R process, resulting in increased adhesion. This postprinting plasma treatment increases the lifetime of the R2R printed modules significantly with modules retaining 80% of their efficiency for ∼3000 h in accelerated conditions. Without plasma treatment, this efficiency level is reached in less than 1000 h.

A DC – DC converter for PEMFC stack power conditioning applications

Fuel cell technology is one of the most sought – after renewable technology. However, the output voltage of fuel cell (FC) stacks is inherently unstable, as such; it is of little or no use for most power supply applications. In addition to the unstable output voltage, FC stacks are susceptible to high current ripples, which can reduce the system’s life expectancy. It is therefore a requirement that the output voltage is stabilised and the high current ripple reduced in order to make FC technology useful. In order to achieve this, a power-conditioning unit (PCU) is interfaced directly to the FC stack module. The PCU is realised by means of a DC – DC converter or DC – AC inverter or a combination of both. This paper presents a PWM DC – DC Interleaved Boost Voltage Multiplier (IBVM) converter as the PCU for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) stack. The mathematical modelling of the converter is validated by simulation in MATLAB/SIMULINK. Important simulation results are presented herein: which show that the output voltage of a PEMFC stack can be stabilised.

Optical modeling of structured silicon-based tandem solar cells and module stacks.

Silicon-based tandem solar cells and modules are complex systems that require optical modeling for the optimization towards highest efficiencies. The fact that such devices typically incorporate surface structures of different optical regimes poses high requirements to the involved simulation tools. The OPTOS formalism is ideally suited to deal with such complexity. Within this work OPTOS is extended in order to calculate the layer resolved absorptance in silicon-based tandem solar cells and module stacks. After describing the relevant mathematical details, a good agreement between OPTOS absorptance simulation results and EQE measurements of the current 33.3% record efficiency III-V on silicon two-terminal tandem solar cell is found. Furthermore, a detailed loss analysis is performed for an exemplary perovskite silicon solar cell with and without module encapsulation. The comparison reveals a lower photocurrent density for the module stack due to increased reflectance and absorption in the EVA.

A versatile computational tool for model-based design, control and diagnosis of a generic Solid Oxide Fuel Cell Integrated Stack Module

This work focuses on the development of a control and diagnosis-oriented model of a Solid Oxide Fuel Cell (SOFC) integrated system module (ISM). Fuel cell researchers and developers are currently investing significant resources on such fuel cell-based energy conversion systems, as a consequence of their adaptability to a variety of applications and power size. In this configuration, heat exchanges among components are difficult to manage and, consequently, reliable model-based tools are required to enhance the design phase. Therefore, the main heat exchange mechanisms (including radiation, here modeled via view-factors-based approach) are evaluated by simplifying 3-D geometries, as well as assuming the outlet temperature from each component as its state variable. The resulting lumped parameters model was proven effective in achieving the required compromise between accuracy and computational time, particularly in view of its real-world deployment for advanced balance of plant (BoP) analyses, as well as within control and diagnostic model-based tasks. Moreover, the entire SOFC ISM model is generic and can be suitably applied to different layouts, through the characterization of main model parameters. Simulation results are in agreement with experimental data collected on a non-conventional micro-CHP system, named HoTBox™, tested under nominal operating conditions within the EU funded project DIAMOND.

Theoretical study of pyramid sizes and scattering effects in silicon photovoltaic module stacks.

Front side pyramids are the industrial standard for wafer based monocrystalline silicon solar cells. These pyramids fulfill two tasks: They act as anti-reflective structure on the one hand and as a light-trapping structure on the other hand. In recent development smaller pyramids with sizes below 1 µm attract more and more interest. In this paper an optical analysis of periodically arranged front side pyramids is performed. The impact on the reflectance as well as on the useful absorption within the solar cell is investigated depending on the pyramids size, the amount of additional scattering in the system and the quality of the rear side reflector. In contrast to other investigations not only the solar cell, but the full photovoltaic (PV) module stack is considered. This can strongly influence results, as we show in this paper. The results indicate that in a PV module stack with realistic assumptions for the amount of scattering as well as for the rear side reflectance only small differences for pyramids with sizes above 600 nm occur. Preliminary conclusions for random pyramids deduced from these results for periodically arranged pyramids indicate that these differences could become even smaller.

Optimal design and analysis of hybrid photovoltaic-fuel cell power generation system for an advanced converter technologies

Nowadays, the entire world is concentrated on alternative energy sources (AES) or renewable energy sources (RES) for developing the power in economical cost and the sources like tidal power, solar energy, geothermal energy, wind energy, biomass, fuel cells etc. Among all those sources solar energy and fuel cells are chosen for developing the hybrid power generation (HPG) system. The photovoltaic (PV) module is designed with an efficient maximum power point tracking (MPPT) technique of neuro-fuzzy (NF) tracking controller is developed to extract the maximum power and fed to boost DC-DC converter. In the meanwhile, air breathe fuel cell (ABFC) is designed and fed to the high step-up DC-DC converter with lesser duty cycle. The main concentration of this paper is to design the efficient HPG system for a competitive multilevel inverter (MLI) topology with less device count is the merit of this topology which is called packed U cell (PUC). In addition, this paper describes the mathematical analysis, design and operation of PV module, neuro-fuzzy (NF) MPPT controller based boost converter, ABFC, high step-up converter and PUC inverter. The P-V, I-V characteristics of PV module and ABFC stack effects on hydrogen pressure changes and temperature is examined. And also, the performance of HPG based PV-FC fed MLI is sifted for different load conditions. The overall performance is checked in terms of total harmonic distortion (THD) for phase voltages (Vph) and phase currents (Iph) which are accomplished through FFT analysis for each load case. The whole simulations are carried out in MATLAB/Simulink environment.

Control-Oriented Models for SO Fuel Cells from the Angle of V&V: Analysis, Simplification Possibilities, Performance

In this paper, we take a look at the analysis and parameter identification for control-oriented, dynamic models for the thermal subsystem of solid oxide fuel cells (SOFC) from the systematized point of view of verification and validation (V&V). First, we give a possible classification of models according to their verification degree which depends, for example, on the kind of arithmetic used for both formulation and simulation. Typical SOFC models, consisting of several coupled differential equations for gas preheaters and the temperature distribution in the stack module, do not have analytical solutions because of spatial nonlinearity. Therefore, in the next part of the paper, we describe in detail two possible ways to simplify such models so that the underlying differential equations can be solved analytically while still being sufficiently accurate to serve as the basis for control synthesis. The simplifying assumption is to approximate the heat capacities of the gases by zero-order polynomials (or first-oder polynomials, respectively) in the temperature. In the last, application-oriented part of the paper, we identify the parameters of these models as well as compare their performance and their ability to reflect the reality with the corresponding characteristics of models in which the heat capacities are represented by quadratic polynomials (the usual case). For this purpose, the framework UniVerMeC (Unified Framework for Verified GeoMetric Computations) is used, which allows us to employ different kinds of arithmetics including the interval one. This latter possibility ensures a high level of reliability of simulations and of the subsequent validation. Besides, it helps to take into account bounded uncertainty in measurements.

Optical performance of the honeycomb texture – a cell and module level analysis using the OPTOS formalism

A comprehensive analysis of the optical properties of different surface textures for silicon solar cells must include (i) the optical performance at cell level as well as encapsulated to a module stack and (ii) a varying angle of incidence of the solar irradiation, as it influences the optical yield. Within this work, the OPTOS formalism (Optical Properties of Textured Optical Sheets) was used to compare a honeycomb texture featuring a high aspect ratio with state of the art random pyramids and the isotexture. The honeycomb texture exhibits an increased absorbed photocurrent density of 2.3mA/cm2 before and 0.7mA/cm2 after encapsulation compared to the isotexture for a 180µm thick solar cell. The simulated absolute value of 42.3mA/cm2 after encapsulation is even superior to the random pyramid texture with 41.5mA/cm2. Furthermore, a simulation-based optical yield analysis reveals that the angular irradiance of three exemplary terrestrial locations plays a minor role for the relative performance between the textures compared to influence of encapsulation effects.

Development of a Highly Flexible SOFC CCHP System Towards Demand-Oriented Power Generation from Renewable Fuels

This paper presents the current development status of AVLs stationary SOFC CCHP (combined cooling, heat and power) platform with special focus on the coupling of an SOFC with an absorption heat pump. Furthermore, the SOFCs fuel capability was extended towards the utilization of multiple renewable fuels such as biogas, biomass product gas and synthetic diesel. In the past AVL developed a natural gas operated SOFC CHP platform in the power range of 5 – 10 kWel with an electrical efficiency of >55 % using the Plansee/IKTS stack technology. For certain applications such as buildings, a heat driven operation mode leads to low operating hours per year for conventional CHP systems due to the low heat demand during summer season. The option to generate cooling power in addition to heat will increase the annual operating hours per year and thus economic efficiency significantly. This work will show the coupling of a stationary 6 kWel SOFC CHP system developed by AVL using an IKTS stack module with a 5 kWcooling absorption heat pump developed by TU Graz, Institute of Thermal Engineering. The exhaust gas heat from the SOFC which is available at >200 °C will be used to operate the thermally driven heat pump. The SOFC exhaust gas heat is transferred in the generator of the absorption heat pump to be converted to cooling power. To maximize the cooling power output of the SOFC CCHP system it is important to utilize as much SOFC exhaust gas heat as possible in the absorption heat pumping process. Furthermore, it is important to optimize the energy efficiency ratio of the absorption heat pump. In this context the influence of the cold and cooling water temperatures of the absorption heat pumping process on the system size and system total efficiency were investigated. It can be shown that for cold and cooling water temperatures as required in office buildings and hospitals a ratio between electrical power and cooling power of 4 - 6 can be achieved by the SOFC CCHP system. This analysis presents the capability of the SOFC CCHP system for a flexible and demand-oriented generation of electricity, heat and cooling power. As the electrical efficiency of the SOFC determines the exhaust gas heat output the system performance was further investigated towards the operation of renewable fuels. Biogas or synthetic diesel for instance may lead to lower electrical efficiencies compared to natural gas. Therefore, the type of fuel also influences the SOFC exhaust mass flow and temperature which is the main driving power for the absorption heat pump. In this work the fuel capability of the platform was extended from natural gas to renewable fuels. From economic point of view it is desired to benefit from volume effects for stacks and balance of plant components which is why AVLs system development approach is oriented towards a multi-fuel platform which requires only minor design adaptions when it comes to the utilization of different fuels including renewables. As a technology provider this approach is certainly a major advantage for customers who are used to a power generation technology that can be easily applied in various regions all over the world while facing varying fuel specifications. Therefore, this work will provide an overview of the most relevant renewable fuels and its composition for stationary SOFC CHP applications. Consequently, design synergies regarding the process design of the hot anode gas recirculation loop in terms of the recirculation ratio and reforming temperature which are influenced by the specific fuel, are shown. A comparison of system performance results based on process simulations will be discussed. The process simulation uses results from specific reforming tests for e.g. biogas and diesel which will be shown. Furthermore, compared to natural gas based systems a considerably higher effort has to be done in terms of the gas cleaning for biogas and biomass product gas. In case of biogas the main impurities are S, Cl, NH3 which need to be eliminated before sending the fuel to the steam reformer and stack respectively. A low cost gas cleaning concept for biogas based on several low temperature adsorption steps was developed by TU Graz. It can be shown that the absorption efficiency is highly depending on the fuel mixture. The influence of CH4, CO2 and H2O was identified to allow a proper design of the gas cleaning unit. Finally, the build-up of the prototype including first test results will be shown in this work.

Development of a Highly Flexible SOFC CCHP System Towards Demand-Oriented Power Generation from Renewable Fuels

The coupling of AVLs 6 kWEL SOFC CHP system using an IKTS stack module with a 5 kWCOLD absorption heat pump developed by TU Graz will be presented. The exhaust gas heat from the SOFC which is available at >200 °C will be used to operate the thermally driven heat pump. The SOFCs fuel capability was extended towards renewable fuels such as biogas, and synthetic diesel using a novel gas cleaning concept. For buildings, a heat driven operation mode leads to low operating hours per year for conventional CHP systems during summer season. Generating cooling power in addition to heat will increase the annual operating hours per year and thus economic efficiency significantly. This analysis presents the capability of the SOFC CCHP system for a flexible and demand-oriented generation of electricity, heat and cooling power and shows how cold and cooling water temperatures influence the overall system size