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Pablo Sanchis - One of the best experts on this subject based on the ideXlab platform.
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integration of commercial alkaline water Electrolysers with renewable energies limitations and improvements
International Journal of Hydrogen Energy, 2016Co-Authors: Alfredo Ursua, Ernesto L Arrios, Julio Pascual, Idoia Sa Marti, Pablo SanchisAbstract:Abstract Hydrogen can be stored, transported and used in a large number of applications in which fossil fuels are currently used. From a sustainable point of view, the synergy existing between hydrogen and renewable energy sources shows great potential. In this respect, hydrogen can be produced from water electrolysis using the electricity generated by renewable systems. This paper studies the integration of a 1 Nm3 h−1 alkaline water Electrolyser with photovoltaic solar energy (PVE) and wind energy (WE) in a stand-alone system. In particular, a one year energy balance of the conventional integration of the Electrolyser with PVE and WE is carried out. To do so, actual weather data are used for irradiance, ambient temperature and wind speed, in addition to the technical specifications and characteristics of a 6.8 kWp PV generator and a 6 kW wind turbine. This energy evaluation reveals the main limitations of commercial Electrolysers, such as the lower operating limit and the number of stops permitted by manufacturers. Two strategies are therefore proposed to improve the integration of conventional Electrolysers, namely to allow the Electrolyser to operate for a period of 10 min under the lower operating limit and to integrate a battery bank. Both strategies achieve successful results, with a reduction in the number of stops by up to 62.1% for the PVE integration and 63.1% for the WE, which should increase the Electrolyser service life, and an increase in energy efficiency by up to 6.3% for the PVE integration and 7.6% for the WE.
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Design of a Programmable Power Supply to study the performance of an alkaline Electrolyser under different operating conditions
2012 IEEE International Energy Conference and Exhibition (ENERGYCON), 2012Co-Authors: Alfredo Ursua, I. San Martin, Pablo SanchisAbstract:The combination of electrolytic hydrogen production systems with renewable energy sources is arousing considerable interest due to the possibility of obtaining a clean and inexhaustible fuel supply. In turn, Electrolysers can play an important role by supporting the operation and energy management of power grids, microgrids and stand-alone systems. In order to optimally integrate Electrolysers into any of these scenarios, it is first essential to have a thorough knowledge of their operating characteristics, in stationary and dynamic conditions, with regard to electrical performance, hydrogen production, efficiency, etc. Consequently, this paper presents the design, development and implementation of a Programmable Power Supply (PPS) that is capable of supplying an electrical current having a wide range of amplitudes and variability. This PPS is used to study and analyse a 1 Nm3/h alkaline Electrolyser under different operating conditions. Specifically, this work presents the stationary electrical characterisation of the Electrolyser, an analysis of the real production of hydrogen and a study of the influence of harmonics on the Electrolyser power consumption.
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photovoltaic hydrogen production with commercial alkaline Electrolysers
18th World Hydrogen Energy Conference, 2010Co-Authors: Alfredo Ursua, Jesus Lopez, Detlef Stolte, E Gubia, Thomas Grube, Pablo Sanchis, Luis MarroyoAbstract:Renewable energy sources and Electrolysis generate the so-called green Hydrogen, a zeroemission and potentially fossil fuel independent energy source. However, the inherent variability of the renewable energy sources implies a mode of operation for which most current Electrolysers have not been designed. This paper analyses the operation of a water Electrolyser fed with photovoltaic (PV) generator electric profile. The system, Integrated by a 1 Nm/h Hydrogenics alkaline Electrolyser and a 5100 W PV generator with 60 BP585 modules, is installed at the Public University of Navarra (Spain). The PV generator profile fed to the Electrolyser is emulated by a custom-made apparatus designed and built by the authors of this paper. The profile is designed according to real irradiance data measured by a calibration cell. The irradiance data are converted to the electric power profile that the PV generator would have delivered in case of having been connected to the Electrolyser by means of a DC/DC converter with maximum power point tracking (MPPT). Finally, from previously measured power-current Electrolyser characteristic curves, the current profile to be delivered to the Electrolyser is obtained and programmed to the electronic device. The Electrolyser was tested for two types of days. During the first day, the irradiance was very stable, whereas during the second day, the irradiance was very variable. The experimental results show an average power consumption rate and an efficiency of 4908 Wh/Nm and 72.1%, on the first day, and 4842 Wh/Nm and 73.3% on the second day. The Electrolyser performance was particularly good in spite of the high variability of the electric supply of the second day.
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influence of the power supply on the energy efficiency of an alkaline water Electrolyser
International Journal of Hydrogen Energy, 2009Co-Authors: Alfredo Ursua, E Gubia, Luis Marroyo, Luis M. Gandía, P M Dieguez, Pablo SanchisAbstract:Abstract Electric energy consumption represents the greatest part of the cost of the hydrogen produced by water electrolysis. An effort is being carried out to reduce this electric consumption and improve the global efficiency of commercial Electrolysers. Whereas relevant progresses are being achieved in cell stack configurations and electrodes performance, there are practically no studies on the effect of the electric power supply topology on the Electrolyser energy efficiency. This paper presents an analysis on the energy consumption and efficiency of a 1 N m3 h−1 commercial alkaline water Electrolyser and their dependence on the power supply topology. The different topologies of power supplies are first summarised, analysed and classified into two groups: thyristor-based (ThPS) and transistor-based power supplies (TrPS). An Electrolyser Power Supply Emulator (EPSE) is then designed, developed and satisfactorily validated by means of simulation and experimental tests. With the EPSE, the Electrolyser is characterised both obtaining its I–V curves for different temperatures and measuring the useful hydrogen production. The Electrolyser is then supplied by means of two different emulated electric profiles that are characteristic of typical ThPS and TrPS. Results show that the cell stack energy consumption is up to 495 W h N m−3 lower when it is supplied by the TrPS, which means 10% greater in terms of efficiency.
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Electronic device for the emulation of wind systems and analysis of alkaline water Electrolysers
2009 13th European Conference on Power Electronics and Applications, 2009Co-Authors: Alfredo Ursua, Jesus Lopez, E Gubia, Luis Marroyo, Pablo SanchisAbstract:This paper proposes an electronic device that emulates the electric power generated by complete wind systems in order to test alkaline water Electrolysers under real operating conditions typical of wind regimes. This Wind Emulator has a rated power of 10 kW. It is first validated by means of experimental tests in order to probe its performance concerning quickness, accuracy and reliability. Afterwards, the Wind Emulator is used to test a commercial alkaline electrolyzer from Hydrogenics, whose nominal production rate is 1 Nm3h-1so as to obtain its electric characteristic curves. Finally, a wind emulation test is carried out based on real wind data applied to the commercial wind turbine INCLIN6000 from Bornay. By means of this test, the electrolyzer behaviour is analyzed when supplied by a wind energy profile. The results obtained in all the experimental tests have been satisfactory.
Alfredo Ursua - One of the best experts on this subject based on the ideXlab platform.
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integration of commercial alkaline water Electrolysers with renewable energies limitations and improvements
International Journal of Hydrogen Energy, 2016Co-Authors: Alfredo Ursua, Ernesto L Arrios, Julio Pascual, Idoia Sa Marti, Pablo SanchisAbstract:Abstract Hydrogen can be stored, transported and used in a large number of applications in which fossil fuels are currently used. From a sustainable point of view, the synergy existing between hydrogen and renewable energy sources shows great potential. In this respect, hydrogen can be produced from water electrolysis using the electricity generated by renewable systems. This paper studies the integration of a 1 Nm3 h−1 alkaline water Electrolyser with photovoltaic solar energy (PVE) and wind energy (WE) in a stand-alone system. In particular, a one year energy balance of the conventional integration of the Electrolyser with PVE and WE is carried out. To do so, actual weather data are used for irradiance, ambient temperature and wind speed, in addition to the technical specifications and characteristics of a 6.8 kWp PV generator and a 6 kW wind turbine. This energy evaluation reveals the main limitations of commercial Electrolysers, such as the lower operating limit and the number of stops permitted by manufacturers. Two strategies are therefore proposed to improve the integration of conventional Electrolysers, namely to allow the Electrolyser to operate for a period of 10 min under the lower operating limit and to integrate a battery bank. Both strategies achieve successful results, with a reduction in the number of stops by up to 62.1% for the PVE integration and 63.1% for the WE, which should increase the Electrolyser service life, and an increase in energy efficiency by up to 6.3% for the PVE integration and 7.6% for the WE.
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Design of a Programmable Power Supply to study the performance of an alkaline Electrolyser under different operating conditions
2012 IEEE International Energy Conference and Exhibition (ENERGYCON), 2012Co-Authors: Alfredo Ursua, I. San Martin, Pablo SanchisAbstract:The combination of electrolytic hydrogen production systems with renewable energy sources is arousing considerable interest due to the possibility of obtaining a clean and inexhaustible fuel supply. In turn, Electrolysers can play an important role by supporting the operation and energy management of power grids, microgrids and stand-alone systems. In order to optimally integrate Electrolysers into any of these scenarios, it is first essential to have a thorough knowledge of their operating characteristics, in stationary and dynamic conditions, with regard to electrical performance, hydrogen production, efficiency, etc. Consequently, this paper presents the design, development and implementation of a Programmable Power Supply (PPS) that is capable of supplying an electrical current having a wide range of amplitudes and variability. This PPS is used to study and analyse a 1 Nm3/h alkaline Electrolyser under different operating conditions. Specifically, this work presents the stationary electrical characterisation of the Electrolyser, an analysis of the real production of hydrogen and a study of the influence of harmonics on the Electrolyser power consumption.
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photovoltaic hydrogen production with commercial alkaline Electrolysers
18th World Hydrogen Energy Conference, 2010Co-Authors: Alfredo Ursua, Jesus Lopez, Detlef Stolte, E Gubia, Thomas Grube, Pablo Sanchis, Luis MarroyoAbstract:Renewable energy sources and Electrolysis generate the so-called green Hydrogen, a zeroemission and potentially fossil fuel independent energy source. However, the inherent variability of the renewable energy sources implies a mode of operation for which most current Electrolysers have not been designed. This paper analyses the operation of a water Electrolyser fed with photovoltaic (PV) generator electric profile. The system, Integrated by a 1 Nm/h Hydrogenics alkaline Electrolyser and a 5100 W PV generator with 60 BP585 modules, is installed at the Public University of Navarra (Spain). The PV generator profile fed to the Electrolyser is emulated by a custom-made apparatus designed and built by the authors of this paper. The profile is designed according to real irradiance data measured by a calibration cell. The irradiance data are converted to the electric power profile that the PV generator would have delivered in case of having been connected to the Electrolyser by means of a DC/DC converter with maximum power point tracking (MPPT). Finally, from previously measured power-current Electrolyser characteristic curves, the current profile to be delivered to the Electrolyser is obtained and programmed to the electronic device. The Electrolyser was tested for two types of days. During the first day, the irradiance was very stable, whereas during the second day, the irradiance was very variable. The experimental results show an average power consumption rate and an efficiency of 4908 Wh/Nm and 72.1%, on the first day, and 4842 Wh/Nm and 73.3% on the second day. The Electrolyser performance was particularly good in spite of the high variability of the electric supply of the second day.
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influence of the power supply on the energy efficiency of an alkaline water Electrolyser
International Journal of Hydrogen Energy, 2009Co-Authors: Alfredo Ursua, E Gubia, Luis Marroyo, Luis M. Gandía, P M Dieguez, Pablo SanchisAbstract:Abstract Electric energy consumption represents the greatest part of the cost of the hydrogen produced by water electrolysis. An effort is being carried out to reduce this electric consumption and improve the global efficiency of commercial Electrolysers. Whereas relevant progresses are being achieved in cell stack configurations and electrodes performance, there are practically no studies on the effect of the electric power supply topology on the Electrolyser energy efficiency. This paper presents an analysis on the energy consumption and efficiency of a 1 N m3 h−1 commercial alkaline water Electrolyser and their dependence on the power supply topology. The different topologies of power supplies are first summarised, analysed and classified into two groups: thyristor-based (ThPS) and transistor-based power supplies (TrPS). An Electrolyser Power Supply Emulator (EPSE) is then designed, developed and satisfactorily validated by means of simulation and experimental tests. With the EPSE, the Electrolyser is characterised both obtaining its I–V curves for different temperatures and measuring the useful hydrogen production. The Electrolyser is then supplied by means of two different emulated electric profiles that are characteristic of typical ThPS and TrPS. Results show that the cell stack energy consumption is up to 495 W h N m−3 lower when it is supplied by the TrPS, which means 10% greater in terms of efficiency.
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Electronic device for the emulation of wind systems and analysis of alkaline water Electrolysers
2009 13th European Conference on Power Electronics and Applications, 2009Co-Authors: Alfredo Ursua, Jesus Lopez, E Gubia, Luis Marroyo, Pablo SanchisAbstract:This paper proposes an electronic device that emulates the electric power generated by complete wind systems in order to test alkaline water Electrolysers under real operating conditions typical of wind regimes. This Wind Emulator has a rated power of 10 kW. It is first validated by means of experimental tests in order to probe its performance concerning quickness, accuracy and reliability. Afterwards, the Wind Emulator is used to test a commercial alkaline electrolyzer from Hydrogenics, whose nominal production rate is 1 Nm3h-1so as to obtain its electric characteristic curves. Finally, a wind emulation test is carried out based on real wind data applied to the commercial wind turbine INCLIN6000 from Bornay. By means of this test, the electrolyzer behaviour is analyzed when supplied by a wind energy profile. The results obtained in all the experimental tests have been satisfactory.
Marcus Newborough - One of the best experts on this subject based on the ideXlab platform.
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Electrolysers as a load management mechanism for power systems with wind power and zero carbon thermal power plant
Applied Energy, 2010Co-Authors: E Troncoso, Marcus NewboroughAbstract:For an isolated power system the deployment of a large stock of Electrolysers is investigated as a means for increasing the penetrations of wind power plant and zero-carbon thermal power plant. Consideration is given to the sizing and utilization of an Electrolyser stock for three Electrolyser implementation cases and three operational strategies, installed capacity ranges of 20-100% for wind power and 10-35% for zero-carbon thermal power plant (as proportions of the power system's maximum electrical demand) were investigated. Relative to wind-hydrogen alone, hydrogen yields are substantially increased especially on low-wind days. The average load placed on fossil-fuelled power plant is substantially decreased (while achieving a virtually flat load profile) and the carbon intensity of electricity can be reduced to values of
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implementation and control of Electrolysers to achieve high penetrations of renewable power
International Journal of Hydrogen Energy, 2007Co-Authors: E Troncoso, Marcus NewboroughAbstract:Abstract The mass deployment of Electrolysers, within a power system serving a region of high wind resource, as the enabling mechanism for achieving five key objectives is assessed (that is: a very high installed capacity of wind power plant (WPP); zero wind curtailment during times of low demand; a very high load factor for thermal power plant; an electricity supply of low-carbon intensity; and a hydrogen supply of low-carbon intensity). Three Electrolyser implementation cases were simulated for three days characterised mainly by wind availability and emphasis was placed on maximizing the smoothness of the load profile (LF) applied to thermal power plant. If zero-carbon hydrogen is to be produced a daily load factor for thermal power plant of 90% is the upper limit, but load factors of up to 100% are achievable if a carbon intensity of 3 kgCO 2 / kgH 2 is permitted. For wind penetrations exceeding approximately 30% of system maximum demand, the Electrolyser stock must include implementations close to WPP if curtailment is to be avoided. To achieve very high wind penetrations and very high load factors for thermal power plant requires a large stock of Electrolysers—for the system investigated approximately 1.1 MW of Electrolyser capacity is required per installed MW of wind power.
E Troncoso - One of the best experts on this subject based on the ideXlab platform.
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off grid test results of a solar powered hydrogen refuelling station for fuel cell powered unmanned aerial vehicles
International Journal of Hydrogen Energy, 2014Co-Authors: E Troncoso, N Lapenarey, O ValeroAbstract:Abstract Fuel cell (FC) propulsion for small (MTOW From the results obtained, the operation of the CPV array and the CPV inverter connected to the Electrolyser were both satisfactory, and no significant operational issues were observed. The overall energy efficiency of the CPV-inverter-Electrolyser system was below 40%, mainly due to the excessively long start-up periods during which the Electrolyser is not producing hydrogen, the slow dynamic response due to regular pressurization and depressurization cycles of the Electrolyser and the excessive power consumption of the Electrolyser auxiliaries. It is expected that if some optimization is carried out, mainly related to the control system of the Electrolyser, the overall energy efficiency should increase and the dynamic response of the Electrolyser can be improved.
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Electrolysers as a load management mechanism for power systems with wind power and zero carbon thermal power plant
Applied Energy, 2010Co-Authors: E Troncoso, Marcus NewboroughAbstract:For an isolated power system the deployment of a large stock of Electrolysers is investigated as a means for increasing the penetrations of wind power plant and zero-carbon thermal power plant. Consideration is given to the sizing and utilization of an Electrolyser stock for three Electrolyser implementation cases and three operational strategies, installed capacity ranges of 20-100% for wind power and 10-35% for zero-carbon thermal power plant (as proportions of the power system's maximum electrical demand) were investigated. Relative to wind-hydrogen alone, hydrogen yields are substantially increased especially on low-wind days. The average load placed on fossil-fuelled power plant is substantially decreased (while achieving a virtually flat load profile) and the carbon intensity of electricity can be reduced to values of
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implementation and control of Electrolysers to achieve high penetrations of renewable power
International Journal of Hydrogen Energy, 2007Co-Authors: E Troncoso, Marcus NewboroughAbstract:Abstract The mass deployment of Electrolysers, within a power system serving a region of high wind resource, as the enabling mechanism for achieving five key objectives is assessed (that is: a very high installed capacity of wind power plant (WPP); zero wind curtailment during times of low demand; a very high load factor for thermal power plant; an electricity supply of low-carbon intensity; and a hydrogen supply of low-carbon intensity). Three Electrolyser implementation cases were simulated for three days characterised mainly by wind availability and emphasis was placed on maximizing the smoothness of the load profile (LF) applied to thermal power plant. If zero-carbon hydrogen is to be produced a daily load factor for thermal power plant of 90% is the upper limit, but load factors of up to 100% are achievable if a carbon intensity of 3 kgCO 2 / kgH 2 is permitted. For wind penetrations exceeding approximately 30% of system maximum demand, the Electrolyser stock must include implementations close to WPP if curtailment is to be avoided. To achieve very high wind penetrations and very high load factors for thermal power plant requires a large stock of Electrolysers—for the system investigated approximately 1.1 MW of Electrolyser capacity is required per installed MW of wind power.
Antonio Urbina - One of the best experts on this subject based on the ideXlab platform.
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simple pem water Electrolyser model and experimental validation
International Journal of Hydrogen Energy, 2012Co-Authors: Rafael Garciavalverde, Nieves Espinosa, Antonio UrbinaAbstract:Abstract We propose in this work a simple model for atmospheric or low-pressure PEM water Electrolysers, which allows for simulating the electrochemical, thermal and H2 output flow behaviours with enough precision for engineering applications. The model has been validated by good agreement with experimental measurements performed in two different Electrolysers. The electrochemical submodel allows for obtaining the operating stack voltage from the input current and the stack temperature conditions. After non-linear fitting and statistical analysis from experimental data we conclude that the electrochemical submodel can be extrapolated for any PEM water Electrolyser knowing two parameters with physical meaning: activation energy of the “water oxidation” for the anode electrocatalyst and the activation energy for proton transport in the solid polymer membrane. This submodel was validated with experimental polarisation curves at different temperatures from two different PEM water Electrolysers. The standard error of the model was less than 0.03. The results showed that the worst values of the estimation were obtained below 50 °C, indicating that the assumption of constant anode charge transfer coefficient is not true at lower temperature, which is in accordance with recent results. In order to complete the electrochemical submodel, a practical methodology is presented here to obtain simple semi-empirical submodels for the H2 production and thermal behaviours for this kind of Electrolysers. Both submodels are also discussed based on the experimental validations.
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optimized method for photovoltaic water Electrolyser direct coupling
International Journal of Hydrogen Energy, 2011Co-Authors: Rafael Garciavalverde, Nieves Espinosa, Antonio UrbinaAbstract:Abstract Photovoltaics and Electrolyser coupling is one of the most promising options for obtaining hydrogen from a renewable energy source. Both are well known technologies and direct coupling is possible; however, due to high variability of the solar radiation, an efficient relative sizing still presents some challenges. In fact, relative sizing is always a key issue when coupling renewable electric sources to water Electrolysers. Few previous works addressed the relative sizing and an easy and efficient method is still missing. This work presents a new method for relative sizing between both components based on simple modelling of both polarisation curves. Modelling and simulation is used for extracting a cloud of maximum power points at all the radiation and temperature conditions for a normalised PV generator. Then, the ideal ratio between the size of components is obtained by fitting a normalised polarisation curve for the Electrolyser to this cloud of maximum power points. PV generator and PEM Electrolyser models are proposed and the method is applied, as example, to two different PEM water Electrolysers. The method helps the relative sizing issue for designing solar hydrogen production systems based on water electrolysis, because it is derived from manufacturer parameters and the used of uncomplicated numerical methods.