The Power to Flex project aims to promote the development of storage possibilities from sustainable energy sources. Hydrogen is opted to be a feasible energy carrier, which can also be stored for prolonged times without further losses and can be transformed into electricity and heat when needed. Producing hydrogen from electrolysis processes has a low CO2 footprint, however the efficiency at both the system, stack and cell level still increases due to further research and development.Electrolysis is conventionally performed with direct current, of which the energy is usually supplied from the grid. Rectifiers are necessary to provide the energy source for electrolysis, which unfortunately waste some of the efficiency, albeit becoming more efficient. Although it is known that distortions, harmonics and ripple, in the current supply can cause decreased performance of the electrolysis, a fundamental understanding is often not provided in published research. Controlled modulation of the electrolysis process can however form a possibility to enhance the performance of electrolysis
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Author supplied from the article: Abstract A temperature compensated hydrogen sensor was designed and made capable of detecting H2 within a broad range of 100–10.000 ppm while compensating instantaneously for large (±25 °C) temperature variations. Two related operational constraints have been simultaneously addressed: (1) Selective, and sensitive detection under large temperature changes, (2) Fast warning at low and increasing H2 levels. Accurate measurements of hydrogen concentrations were enabled by matching relevant time-constants. This was achieved with a microchip having two temperature coupled palladium nanowires. One of the H2 sensitive Pd nanowires was directly exposed to hydrogen, whilst the other nanowire was used as a temperature sensor and as a reference. A drop forging technique was used to passivate the second Pd wire against H2 sensing. Temperature effects could be substantially reduced with a digital signal processing algorithm. Measurements were done in a test chamber, enabling the hydrogen concentration to be controlled over short and long periods. An early response for H2 sensing is attainable in the order of 600 milliseconds and an accurate value for the absolute hydrogen concentration can be obtained within 15 s.
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This paper proposes a Hybrid Microgrid (HμG) model including distributed generation (DG) and a hydrogen-based storage system, controlled through a tailored control strategy. The HμG is composed of three DG units, two of them supplied by solar and wind sources, and the latter one based on the exploitation of theProton Exchange Membrane (PEM) technology. Furthermore, the system includes an alkaline electrolyser, which is used as a responsive load to balance the excess of Variable Renewable Energy Sources (VRES) production, and to produce the hydrogen that will be stored into the hydrogen tank and that will be used to supply the fuel cell in case of lack of generation. The main objectives of this work are to present a validated dynamic model for every component of the HμG and to provide a strategy to reduce as much as possible the power absorption from the grid by exploiting the VRES production. The alkaline electrolyser and PEM fuel cell models are validated through real measurements. The State of Charge (SoC) of the hydrogen tank is adjusted through an adaptive scheme. Furthermore, the designed supervisor power control allows reducing the power exchange and improving the system stability. Finally, a case, considering a summer load profile measured in an electrical substation of Politecnico di Torino, is presented. The results demonstrates the advantages of a hydrogen-based micro-grid, where the hydrogen is used as medium to store the energy produced by photovoltaic and wind systems, with the aim to improve the self-sufficiency of the system
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Carbon dioxide (CO2) is the final waste product for all carbon-containing products. Its reuse will partly mitigate climate change and, in addition, provide a valuable feedstock for fuels and chemicals. Zuyd University of Applied Sciences (ZUYD), Innosyn B.V., and Chemtrix B.V. will develop a flow reactor for photochemical reactions with gases conducted at high pressure. This reactor is the necessary first development towards artificial photosynthesis: the connection of hydrogen (H2) to the ultimate waste product CO2 to store energy in a chemical bond, in order to produce so-called solar fuels and C1-chemicals/products. With an increasing amount of renewables in the energy system, energy storage becomes increasingly important to continuously match supply and demand. In a cooperation between three ZUYD research groups with Chemtrix B.V. and Innosyn B.V., multiple cost-efficient reactor designs for this flow reactor will be analyzed and two designs will be selected to be implemented by small extensions of existing equipment. Simultaneously, two appropriate test re-actions involving a gas (E-Z isomerization followed by hydrogenation) and with a CO2 analogue (a hydrogenation of a carboxylic acid) will be developed to be conducted in the reactor when the con-struction has been finished. We aim to disseminate the new capabilities developed in this KIEM proposal by the project partners with respect to the new reactors to several selected stakeholders. Furthermore, to expand the project several options (SIA-RAAK and H2020 grants) will be explored.
