The intermittency of renewable energy technologies requires adequate storage technologies. Hydrogen systems consisting of electrolysers, storage tanks, and fuel cells can be implemented as well as batteries. The requirements of the hydrogen purification unit is missing from literature. We measured the same for a 4.5 kW PEM electrolyser to be 0.8 kW for 10 min.A simulation to hybridize the hydrogen system, including its purification unit, with lithium-ion batteries for energy storage is presented; the batteries also support the electrolyser. We simulated a scenario for operating a Dutch household off-electric-grid using solar and wind electricity to find the capacities and costs of the components of the system.Although the energy use of the purification unit is small, it influences the operation of the system, affecting the sizing of the components. The battery as a fast response efficient secondary storage system increases the ability of the electrolyser to start up.
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The European Commission has selected the Northern Netherlands to become the leading European hydrogen region and supports establishment of a complete local (green) hydrogen ecosystem covering production, storage, distribution, refueling and final use of hydrogen (Cordis, H2Valley, 2019). In line with the European recognition, the Dutch government has set the goal to establish a hydrogen ecosystem by 2025 that would further expand to Western Europe by 2030. Yet before the European Union nominated the Northern Netherlands as European Hydrogen Valley, the key stakeholders in the Northern Netherlands – industry, SMEs, knowledge institutions and government – committed to the long-term cooperation in development of the green hydrogen market. Subsequently, the three regional governments of the Northern Netherlands, - Groningen, Friesland and Drenthe, - prepared the common Hydrogen Investment Agenda (2019), which was further elaborated in the common Hydrogen Investment Plan (2020). The latter includes investments amounting to over 9 billion euro, which is believed will secure some 66.000 existing jobs and help create between 25 thousands (in 2030) and 41 thousands (in 2050) new jobs.However, implementation of these ambitious plans to establish a hydrogen ecosystem of this scale will require not only investments into development of a new infrastructure or technological adaptation of present energy systems, e.g., pipelines, but also facilitation of economic transformation and securing the social support and acceptance. What are the prospects for the social support for the developing European Hydrogen Valley in the Northern Netherlands and its acceptance by inhabitants? The paper discusses the social support and acceptance aspects for a hydrogen ecosystem in the context of regional experiences of energy transition, including the concerns of energy justice, safety, and public trust that were raised in the recent past.
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This report describes the creation and use of a database for energy storage technologies which was developed in conjunction with Netbeheer Nederland and the Hanze University of Applied Sciences. This database can be used to make comparisons between a selection of storage technologies and will provide a method for ranking energy storage technology suitability based on the desired application requirements. In addition, this document describes the creation of the energy storage label which contains detailed characteristics for specific storage systems. The layout of the storage labels enables the analysis of different storage technologies in a comprehensive, understandable and comparative manner. A sampling of storage technology labels are stored in an excel spreadsheet and are also compiled in Appendix I of this report; the storage technologies represented here were found to be well suited to enable flexibility in energy supply and to potentially provide support for renewable energy integration [37] [36]. The data in the labels is presented on a series of graphs to allow comparisons of the technologies. Finally, the use and limitations of energy storage technologies are discussed. The results of this research can be used to support the Dutch enewable Energy Transition by providing important information regarding energy storage in both technically detailed and general terms. This information can be useful for energy market parties in order to analyze the role of storage in future energy scenarios and to develop appropriate strategies to ensure energy supply.
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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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Within the Flexnode Plus project the long-term degradation characteristics of a proton exchange membrane (PEM) electrolyzer (5.5 kW, AC, 1 Nm3/h H2) and fuel cell (1.0 kW, DC, 0.9 Nm3/h) was experimentally tested. The electrolyzer unit was operated at various loads and pressures for approximately 750 hours in total, while the fuel cell was operated at a constant load of 1 Ω resistance for approximately 1120 hours in total. The efficiency of the hydrogen production in the electrolyzer and the electricity production in the fuel cell was expressed using the hourly average system efficiency and average cell efficiency. Inorder to predict the state of health and remaining lifetime of the electrolyzer cell and fuel cell, the decay of the cell voltage over time was monitored and the direct mapping from aging data method was used.The electrolyzer cell showed a stable cell voltage and cell efficiency in the studied time period, with an average cell voltage decay rate of 0.5 μV/h. The average cell voltage of the fuel cell dropped with a rate of 2 μV/h during the studied time period.
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This report focuses on the feasibility of the power-to-ammonia concept. Power-to-ammonia uses produced excess renewable electricity to electrolyze water, and then to react the obtained hydrogen with nitrogen, which is obtained through air separation, to produce ammonia. This process may be used as a “balancing load” to consume excess electricity on the grid and maintain grid stability. The product, ammonia, plays the role of a chemical storage option for excess renewable energy. This excess energy in the form of ammonia can be stored for long periods of time using mature technologies and an existing global infrastructure, and can further be used either as a fuel or a chemical commodity. Ammonia has a higher energy density than hydrogen; it is easier to store and transport than hydrogen, and it is much easier to liquefy than methane, and offers an energy chain with low carbon emissions.The objective of this study is to analyze technical, institutional and economic aspects of power-to-ammonia and the usage of ammonia as a flexible energy carrier.
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With increased share of energy generated from variable renewable sources, storagebecomes a critical issue to ensure constantly balanced supply/demand.Methane is a promising vector for energy storage and transport.
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Wind and solar power generation will continue to grow in the energy supply of the future, but its inherent variability (intermittency) requires appropriate energy systems for storing and using power. Storage of possibly temporary excess of power as methane from hydrogen gas and carbon dioxide is a promising option. With electrolysis hydrogen gas can be generated from (renewable) power. The combination of such hydrogen with carbon dioxide results in the energy carrier methane that can be handled well and may may serve as carbon feedstock of the future. Biogas from biomass delivers both methane and carbon dioxide. Anaerobic microorganisms can make additional methane from hydrogen and carbon dioxide in a biomethanation process that compares favourably with its chemical counterpart. Biomethanation for renewable power storage and use makes appropriate use of the existing infrastructure and knowledge base for natural gas. Addition of hydrogen to a dedicated biogas reactor after fermentation optimizes the biomethanation conditions and gives maximum flexibility. The low water solubility of hydrogen gas limits the methane production rate. The use of hollow fibers, nano-bubbles or better-tailored methane-forming microorganisms may overcome this bottleneck. Analyses of patent applications on biomethanation suggest a lot of freedom to operate. Assessment of biomethanation for economic feasibility and environmental value is extremely challenging and will require future data and experiences. Currently biomethanation is not yet economically feasible, but this may be different in the energy systems of the near future.
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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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