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Energy needs in urban areas are heterogeneous by their nature, spatial distribution and temperature level required. Three concepts of district energy networks that could provide the energy services efficiently to a city centre are compared. The focus is on the energy and technological aspects. These networks are characterized by similar temperature levels; between 9.5 °C and 18 °C, rely on free cooling for most of the cooling services and use a combination of centralized and decentralized heat pumps to provide the heating services. Two of these concepts exploit the latent heat of evaporation/condensation of CO2 and of the refrigerant R1234yf to store and transfer heat. The third concept is more conventional and uses the sensible heat of liquid water, however with a small temperature spread. The proposed networks allow the waste heat emitted by the users requiring cooling to be transferred and valourised by the users requiring heating, thus reducing the load on the central plant. For the area considered, where the annual heating and cooling demand are 53.1 GWh and 49.4 GWh respectively, the annual electricity required to supply the thermal services amounts to 10.87 GWh for CO2, 10.52 GWh for water and 9.60 GWh for R1234yf.
Samuel Henchoz; Patrick Chatelan; Francois Marechal; Daniel Favrat. Key energy and technological aspects of three innovative concepts of district energy networks. Energy 2016, 117, 465 -477.
AMA StyleSamuel Henchoz, Patrick Chatelan, Francois Marechal, Daniel Favrat. Key energy and technological aspects of three innovative concepts of district energy networks. Energy. 2016; 117 ():465-477.
Chicago/Turabian StyleSamuel Henchoz; Patrick Chatelan; Francois Marechal; Daniel Favrat. 2016. "Key energy and technological aspects of three innovative concepts of district energy networks." Energy 117, no. : 465-477.
Victor Codina Gironès; Stefano Moret; François Maréchal; Daniel Favrat. Strategic energy planning for large-scale energy systems: A modelling framework to aid decision-making. Energy 2015, 90, 173 -186.
AMA StyleVictor Codina Gironès, Stefano Moret, François Maréchal, Daniel Favrat. Strategic energy planning for large-scale energy systems: A modelling framework to aid decision-making. Energy. 2015; 90 ():173-186.
Chicago/Turabian StyleVictor Codina Gironès; Stefano Moret; François Maréchal; Daniel Favrat. 2015. "Strategic energy planning for large-scale energy systems: A modelling framework to aid decision-making." Energy 90, no. : 173-186.
Samuel Henchoz; Céline Weber; François Maréchal; Daniel Favrat. Performance and profitability perspectives of a CO2 based district energy network in Geneva's City Centre. Energy 2015, 85, 221 -235.
AMA StyleSamuel Henchoz, Céline Weber, François Maréchal, Daniel Favrat. Performance and profitability perspectives of a CO2 based district energy network in Geneva's City Centre. Energy. 2015; 85 ():221-235.
Chicago/Turabian StyleSamuel Henchoz; Céline Weber; François Maréchal; Daniel Favrat. 2015. "Performance and profitability perspectives of a CO2 based district energy network in Geneva's City Centre." Energy 85, no. : 221-235.
This chapter contains sections titled: Introduction Structuring Phase Optimization Phase The Postprocessing Phase Resolution Strategy of the Optimization Phase Mathematical Formulation of the Optimization Phase Test Case Application Optimization Conclusions References
François Maréchal; Céline Weber; Daniel Favrat. Multiobjective Design and Optimization of Urban Energy Systems. Process Systems Engineering 2014, 39 -83.
AMA StyleFrançois Maréchal, Céline Weber, Daniel Favrat. Multiobjective Design and Optimization of Urban Energy Systems. Process Systems Engineering. 2014; ():39-83.
Chicago/Turabian StyleFrançois Maréchal; Céline Weber; Daniel Favrat. 2014. "Multiobjective Design and Optimization of Urban Energy Systems." Process Systems Engineering , no. : 39-83.
Leonidas Tsikonis; Joel Albrektsson; Jan Van Herle; Daniel Favrat. The effect of bias in gas temperature measurements on the control of a Solid Oxide Fuel Cells system. Journal of Power Sources 2014, 245, 19 -26.
AMA StyleLeonidas Tsikonis, Joel Albrektsson, Jan Van Herle, Daniel Favrat. The effect of bias in gas temperature measurements on the control of a Solid Oxide Fuel Cells system. Journal of Power Sources. 2014; 245 ():19-26.
Chicago/Turabian StyleLeonidas Tsikonis; Joel Albrektsson; Jan Van Herle; Daniel Favrat. 2014. "The effect of bias in gas temperature measurements on the control of a Solid Oxide Fuel Cells system." Journal of Power Sources 245, no. : 19-26.
Matthias Bendig; Francois Marechal; Daniel Favrat. Defining “Waste Heat” for industrial processes. Applied Thermal Engineering 2013, 61, 134 -142.
AMA StyleMatthias Bendig, Francois Marechal, Daniel Favrat. Defining “Waste Heat” for industrial processes. Applied Thermal Engineering. 2013; 61 (1):134-142.
Chicago/Turabian StyleMatthias Bendig; Francois Marechal; Daniel Favrat. 2013. "Defining “Waste Heat” for industrial processes." Applied Thermal Engineering 61, no. 1: 134-142.
Matteo Morandin; Mehmet Mercangöz; Jaroslav Hemrle; Francois Marechal; Daniel Favrat. Thermoeconomic design optimization of a thermo-electric energy storage system based on transcritical CO2 cycles. Energy 2013, 58, 571 -587.
AMA StyleMatteo Morandin, Mehmet Mercangöz, Jaroslav Hemrle, Francois Marechal, Daniel Favrat. Thermoeconomic design optimization of a thermo-electric energy storage system based on transcritical CO2 cycles. Energy. 2013; 58 ():571-587.
Chicago/Turabian StyleMatteo Morandin; Mehmet Mercangöz; Jaroslav Hemrle; Francois Marechal; Daniel Favrat. 2013. "Thermoeconomic design optimization of a thermo-electric energy storage system based on transcritical CO2 cycles." Energy 58, no. : 571-587.
The present paper is the third and last part of an investigation on what determines reliability in fuel cell model identification. In continuation to the effect of experimental design (Part I) and a process method for stochastic calculation of a model's parameters (Part II), this paper concentrates on the assessment of a model validation. Four criteria are examined. The fit of the model's output to experimental data, the determinant of the covariance matrix of the parameters, the determinant of their correlation matrix, and the product of their variances. As regards the fit to the data, results show that this is mainly a function of the number of measurement points. Repetitions do not seem to improve the average of the fit significantly, but it does improve its variation. For the other three criteria, which are also mathematically linked, results show a counterbalance between them, leading to the conclusion that they cannot be optimized simultaneously. This happens especially between the determinants of the covariance and the correlation matrices.
L. Tsikonis; J. Van Herle; Daniel Favrat. Investigating Reliability on Fuel Cell Model Identification. Part III: Behavior of Assessment Criteria and Limits in Identification. Fuel Cells 2013, 13, 1 .
AMA StyleL. Tsikonis, J. Van Herle, Daniel Favrat. Investigating Reliability on Fuel Cell Model Identification. Part III: Behavior of Assessment Criteria and Limits in Identification. Fuel Cells. 2013; 13 (5):1.
Chicago/Turabian StyleL. Tsikonis; J. Van Herle; Daniel Favrat. 2013. "Investigating Reliability on Fuel Cell Model Identification. Part III: Behavior of Assessment Criteria and Limits in Identification." Fuel Cells 13, no. 5: 1.
Young-Min Kim; Dong-Gil Shin; Sun-Youp Lee; Daniel Favrat. Isothermal transcritical CO2 cycles with TES (thermal energy storage) for electricity storage. Energy 2013, 49, 484 -501.
AMA StyleYoung-Min Kim, Dong-Gil Shin, Sun-Youp Lee, Daniel Favrat. Isothermal transcritical CO2 cycles with TES (thermal energy storage) for electricity storage. Energy. 2013; 49 ():484-501.
Chicago/Turabian StyleYoung-Min Kim; Dong-Gil Shin; Sun-Youp Lee; Daniel Favrat. 2013. "Isothermal transcritical CO2 cycles with TES (thermal energy storage) for electricity storage." Energy 49, no. : 484-501.
As more and more solar tower thermal power plants are being operated, built or planned, effort is put both on the development and research to bring costs down and increase the plant efficiency. In those plants, the central receiver is one of the key components, accounting for a large investment share. Receivers have to sustain strong thermal stresses caused by irradiation transients, mainly due to cloud passages. To avoid premature failures, increase the receiver cyclic life, and allow longer daily operation periods, an anticipation of the most likely or the worst situations is required. First the calculation of the receiver incident flux distribution is performed, second the cloud and cloud passage characteristics are identified for a given location, third the most likely case is simulated by covering and uncovering the heliostat field, then a worst case configuration is presented, and finally a strategy for the start-up/shut-down of the heliostats is proposed. The value of terms such as the heat flux peak, the maximal flux gradient, the fastest flux transient and total power transients are needed to choose the control strategies regarding heliostat orientation and the receiver operation, as well as the elimination of some bad plant layouts during the design phase.
Germain Augsburger; Daniel Favrat. Modelling of the receiver transient flux distribution due to cloud passages on a solar tower thermal power plant. Solar Energy 2013, 87, 42 -52.
AMA StyleGermain Augsburger, Daniel Favrat. Modelling of the receiver transient flux distribution due to cloud passages on a solar tower thermal power plant. Solar Energy. 2013; 87 ():42-52.
Chicago/Turabian StyleGermain Augsburger; Daniel Favrat. 2013. "Modelling of the receiver transient flux distribution due to cloud passages on a solar tower thermal power plant." Solar Energy 87, no. : 42-52.
The solid oxide fuel cell (SOFC) technology has to face many challenges before its large-scale commercialisation. Costs reduction, along with enhanced reliability, durability, fuel flexibility, load following capabilities and compactness are needed. Yet, despite all the research, the exact underlying mechanisms of the electrochemical reactions have not yet been unambiguously identified. The high-temperature environment promotes physicochemical modifications of the materials that alter the electrochemical and mechanical properties after prolonged use. The driving forces of these degradation processes that arise from chemical interactions between the SOFC materials themselves, on the one hand, and the volatile contaminants transported by the fed gases, on the other hand, have not yet been fully clarified.
Arata Nakajo; Jan Van Herle; Daniel Favrat. Current State of Models for the Prediction of Mechanical Failures in Solid Oxide Fuel Cells. Smart and Sustainable Planning for Cities and Regions 2012, 121 -162.
AMA StyleArata Nakajo, Jan Van Herle, Daniel Favrat. Current State of Models for the Prediction of Mechanical Failures in Solid Oxide Fuel Cells. Smart and Sustainable Planning for Cities and Regions. 2012; ():121-162.
Chicago/Turabian StyleArata Nakajo; Jan Van Herle; Daniel Favrat. 2012. "Current State of Models for the Prediction of Mechanical Failures in Solid Oxide Fuel Cells." Smart and Sustainable Planning for Cities and Regions , no. : 121-162.
Arata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. Progressive activation of degradation processes in solid oxide fuel cells stacks: Part I: Lifetime extension by optimisation of the operating conditions. Journal of Power Sources 2012, 216, 449 -463.
AMA StyleArata Nakajo, Fabian Mueller, Jacob Brouwer, Jan Van Herle, Daniel Favrat. Progressive activation of degradation processes in solid oxide fuel cells stacks: Part I: Lifetime extension by optimisation of the operating conditions. Journal of Power Sources. 2012; 216 ():449-463.
Chicago/Turabian StyleArata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. 2012. "Progressive activation of degradation processes in solid oxide fuel cells stacks: Part I: Lifetime extension by optimisation of the operating conditions." Journal of Power Sources 216, no. : 449-463.
Arata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. Progressive activation of degradation processes in solid oxide fuel cell stacks: Part II: Spatial distribution of the degradation. Journal of Power Sources 2012, 216, 434 -448.
AMA StyleArata Nakajo, Fabian Mueller, Jacob Brouwer, Jan Van Herle, Daniel Favrat. Progressive activation of degradation processes in solid oxide fuel cell stacks: Part II: Spatial distribution of the degradation. Journal of Power Sources. 2012; 216 ():434-448.
Chicago/Turabian StyleArata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. 2012. "Progressive activation of degradation processes in solid oxide fuel cell stacks: Part II: Spatial distribution of the degradation." Journal of Power Sources 216, no. : 434-448.
Samuel Henchoz; Florian Buchter; Daniel Favrat; Matteo Morandin; Mehmet Mercangöz. Thermoeconomic analysis of a solar enhanced energy storage concept based on thermodynamic cycles. Energy 2012, 45, 358 -365.
AMA StyleSamuel Henchoz, Florian Buchter, Daniel Favrat, Matteo Morandin, Mehmet Mercangöz. Thermoeconomic analysis of a solar enhanced energy storage concept based on thermodynamic cycles. Energy. 2012; 45 (1):358-365.
Chicago/Turabian StyleSamuel Henchoz; Florian Buchter; Daniel Favrat; Matteo Morandin; Mehmet Mercangöz. 2012. "Thermoeconomic analysis of a solar enhanced energy storage concept based on thermodynamic cycles." Energy 45, no. 1: 358-365.
Energy storage systems are increasingly gaining importance with regard to their role in achieving load levelling, especially for matching intermittent sources of renewable energy with customer demand, as well as for storing excess nuclear or thermal power during the daily cycle. Compressed air energy storage (CAES), with its high reliability, economic feasibility, and low environmental impact, is a promising method for large-scale energy storage. Although there are only two large-scale CAES plants in existence, recently, a number of CAES projects have been initiated around the world, and some innovative concepts of CAES have been proposed. Existing CAES plants have some disadvantages such as energy loss due to dissipation of heat of compression, use of fossil fuels, and dependence on geological formations. This paper reviews the main drawbacks of the existing CAES systems and presents some innovative concepts of CAES, such as adiabatic CAES, isothermal CAES, micro-CAES combined with air-cycle heating and cooling, and constant-pressure CAES combined with pumped hydro storage that can address such problems and widen the scope of CAES applications, by energy and exergy analyses. These analyses greatly help us to understand the characteristics of each CAES system and compare different CAES systems.
Young-Min Kim; Jang-Hee Lee; Seok-Joon Kim; Daniel Favrat. Potential and Evolution of Compressed Air Energy Storage: Energy and Exergy Analyses. Entropy 2012, 14, 1501 -1521.
AMA StyleYoung-Min Kim, Jang-Hee Lee, Seok-Joon Kim, Daniel Favrat. Potential and Evolution of Compressed Air Energy Storage: Energy and Exergy Analyses. Entropy. 2012; 14 (8):1501-1521.
Chicago/Turabian StyleYoung-Min Kim; Jang-Hee Lee; Seok-Joon Kim; Daniel Favrat. 2012. "Potential and Evolution of Compressed Air Energy Storage: Energy and Exergy Analyses." Entropy 14, no. 8: 1501-1521.
L. Tsikonis; S. Diethelm; H. Seiler; A. Nakajo; J. Van Herle; Daniel Favrat. Investigating Reliability on Fuel Cell Model Identification. Part II: An Estimation Method for Stochastic Parameters. Fuel Cells 2012, 12, 685 -708.
AMA StyleL. Tsikonis, S. Diethelm, H. Seiler, A. Nakajo, J. Van Herle, Daniel Favrat. Investigating Reliability on Fuel Cell Model Identification. Part II: An Estimation Method for Stochastic Parameters. Fuel Cells. 2012; 12 (5):685-708.
Chicago/Turabian StyleL. Tsikonis; S. Diethelm; H. Seiler; A. Nakajo; J. Van Herle; Daniel Favrat. 2012. "Investigating Reliability on Fuel Cell Model Identification. Part II: An Estimation Method for Stochastic Parameters." Fuel Cells 12, no. 5: 685-708.
Y.M. Kim; C.G. Kim; Daniel Favrat. Transcritical or supercritical CO2 cycles using both low- and high-temperature heat sources. Energy 2012, 43, 402 -415.
AMA StyleY.M. Kim, C.G. Kim, Daniel Favrat. Transcritical or supercritical CO2 cycles using both low- and high-temperature heat sources. Energy. 2012; 43 (1):402-415.
Chicago/Turabian StyleY.M. Kim; C.G. Kim; Daniel Favrat. 2012. "Transcritical or supercritical CO2 cycles using both low- and high-temperature heat sources." Energy 43, no. 1: 402-415.
Arata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. Mechanical reliability and durability of SOFC stacks. Part II: Modelling of mechanical failures during ageing and cycling. International Journal of Hydrogen Energy 2012, 37, 9269 -9286.
AMA StyleArata Nakajo, Fabian Mueller, Jacob Brouwer, Jan Van Herle, Daniel Favrat. Mechanical reliability and durability of SOFC stacks. Part II: Modelling of mechanical failures during ageing and cycling. International Journal of Hydrogen Energy. 2012; 37 (11):9269-9286.
Chicago/Turabian StyleArata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. 2012. "Mechanical reliability and durability of SOFC stacks. Part II: Modelling of mechanical failures during ageing and cycling." International Journal of Hydrogen Energy 37, no. 11: 9269-9286.
Arata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. Mechanical reliability and durability of SOFC stacks. Part I : Modelling of the effect of operating conditions and design alternatives on the reliability. International Journal of Hydrogen Energy 2012, 37, 9249 -9268.
AMA StyleArata Nakajo, Fabian Mueller, Jacob Brouwer, Jan Van Herle, Daniel Favrat. Mechanical reliability and durability of SOFC stacks. Part I : Modelling of the effect of operating conditions and design alternatives on the reliability. International Journal of Hydrogen Energy. 2012; 37 (11):9249-9268.
Chicago/Turabian StyleArata Nakajo; Fabian Mueller; Jacob Brouwer; Jan Van Herle; Daniel Favrat. 2012. "Mechanical reliability and durability of SOFC stacks. Part I : Modelling of the effect of operating conditions and design alternatives on the reliability." International Journal of Hydrogen Energy 37, no. 11: 9249-9268.
Emanuele Facchinetti; Martin Gassner; Matilde D’Amelio; Francois Marechal; Daniel Favrat. Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass. Energy 2012, 41, 408 -419.
AMA StyleEmanuele Facchinetti, Martin Gassner, Matilde D’Amelio, Francois Marechal, Daniel Favrat. Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass. Energy. 2012; 41 (1):408-419.
Chicago/Turabian StyleEmanuele Facchinetti; Martin Gassner; Matilde D’Amelio; Francois Marechal; Daniel Favrat. 2012. "Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass." Energy 41, no. 1: 408-419.