111,912 research outputs found
Coupling of Biomass Gasification and SOFC - Gas Turbine Hybrid System for Small Scale Cogeneration Applications
No full textIn this study the performances of small cogeneration power plants fed by biomass and based on conventional and advanced technologies are presented. Three system configurations have been considered and analyzed. They are characterized by: a) a biomass gasification (G) unit, based on down-draft technology; b) a power unit, based on the SOFC technology or on the micro gas turbine (MGT) technology or on a hybrid configuration SOFC-MGT; c) a thermal recovery unit. The energy analysis of the proposed power plants has been conducted by using thermochemical/thermodynamic models able to study the integrated systems and each unit in terms of operating and performance parameters. © 2017 The Authors
Electrical energy storage systems based on resoc technology: A novel approach for the grid integration of renewable energy sources
No full textThe aim of this study is to analyze the behavior and the performance of an integrated power plant in which a renewable energy system, based on photovoltaic and wind power units, is coupled with a hydrogen energy storage system. The storage system is based on the ReSOC (Reversible Solid Oxide Cell) technology, that is an electrochemical device able to work both as fuel cell and as electrolyzer. The role of the storage unit is to permit a constant power grid feeding. Thus, the integrated power system has to be managed in order to feed into the grid the electric energy that the renewable power plant is able to produce during its annual operation, but with a power supplying that is constant in time. This operation mode implies that if the stored hydrogen is not available to assure a constant power feeding, an auxiliary power system is used for satisfying the power requirement
Design and performance assessment of a combined heat, hydrogen and power (CHHP) system based on ammonia-fueled SOFC
No full textIn this paper a small-scale combined heat, hydrogen and power (CHHP) system, in which ammonia is used as a fuel for a solid oxide fuel cell (SOFC) to produce 100 kg/day of hydrogen (for refueling up to 20–30 fuel cell vehicles) as well as electricity for electric vehicles fast charging and heat for local use, is proposed. The study is carried out by means of experimental and numerical analysis; in particular, the behaviour of a single solid oxide cell fed by ammonia is investigated through experimental tests, while the design and the performance assessment of the proposed CHHP plant configurations are predicted by means of a thermo-electrochemical model, properly developed. The employed methodology and procedure are based on the SOFC power unit “sizing approach” that is performed through two different design concepts: (a) the minimum SOFC power unit size that allows to produce hydrogen and electricity for self-sustaining the electric power demand of the system; (b) the minimum SOFC power unit size that allows to produce hydrogen, to satisfy the system electric power demand and to supply electricity for EVs fast charging. Results in terms of performance (referred to the high heating values of input and output fuels) highlight that low values of electrical efficiency (14% for Concept_2) and thermal efficiency (≤15% for Concept_1 and Concept_2) are achieved, due to the high conversion of ammonia in hydrogen (the hydrogen production efficiencies are 70% and 42%, respectively), while the trigeneration efficiencies are high (81% and 71%). © 2018 Elsevier Lt
Towards the Italian fuel cells and hydrogen platform
No full textIn Italy the presence of an active scientific community on hydrogen and fuel cells is becoming more and more evident: an industrial sector committed to turn the innovative technological opportunities of these technologies into effective business opportunities and several public institutions supporting the integration of scientific community and industry actions. However, these initiatives often remain dispersed and efforts not sufficiently integrated. Activities are restricted to the technical experts, failing to arrive at the level of the decision makers who are in the position to establish a national framework and identify guidelines and priorities in accordance with other European countries. Indeed, despite repeated attempts to stimulate cohesive government intervention, a national platform on FC&H2 has not yet been launched as in other countries of the world. The Italian National Agency for New Technologies, Energy and Sustainable Economic development (ENEA) and the University of Perugia (Unipg) are promoting the establishment of the Italian Fuel Cells and Hydrogen Platform in order to coordinate efforts for the development of critical technologies for the whole hydrogen cycle (production, delivery, storage, conversion and end use applications) and the overcoming of barriers, in other words, to act as a country system. The present abstract describes the activities performed so far and highlights the results achieved up to date towards the official launch of the Platform
Control strategy optimization for a micro-cogeneration power system based on solid oxide fuel cell
No full textMicro-cogeneration systems have received increasing attention in recent years because, by providing both useful electricity and heat with high efficiency, they can have a strategic role in the reduction of greenhouse gas emissions according to the European Union targets. The European Union directive 2004/8/EC introduces a performance parameter (PES, Primary Energy Saving) that allows to define the performance of the cogeneration systems. Cogeneration applications in buildings have to satisfy either both electrical and thermal demands, or satisfy the thermal demand and part of the electrical demand, or satisfy the electrical demand and part of the thermal demand. Therefore, depending on the electrical and thermal loads and on the operating strategy, a cogeneration system can be run at different conditions. In this paper, a micro-cogenerator (μCHP) based on the Solid Oxide Fuel Cells (SOFC) technology working under different control strategies is investigated and its overall performances have been evaluated
Energy analysis of a cogeneration system based on molten carbonate fuel cell
No full textIn recent years, countries around the world are trying to use high efficiency plants to produce energy with low fuel consumption and consequently low operation costs. The molten carbonate fuel cell (MCFC) power plant is an emerging high efficiency, ultra-clean power generator utilizing a variety of gaseous, liquid and solid carbonaceous fuels for commercial and industrial applications with an electrical efficiency exceeding 45%. Therefore, the high temperature of the exhaust gas exiting from cathode side makes MCFC suited for co-generation. The cogeneration system includes processes of production of combined heating and power (CHP) from a single fuel source. This combined solution allows high levels of overall energy efficiency, lower emissions and security of supply. As well as, this solution privileges the reduction of CO2 emission compared with traditional systems. In this study, either energy or economic (SPB, VAN, TIR) analysis of a co-generation plant based on MCFC technology fed with natural gas is conducted
Low cost combined voltage and current transducer for Smart Meters
No full textOne of the key factor for a capillary adoption of smart grid approach in residential or commercial environments is the availability of low cost devices able to carry on required measurement and control tasks. The development and commercialization of low cost smart meters will be an important field of manufacturing in the next future. On the other hand, in addition to simple measurement of energy flows for billing purposes, there is a great interest in customers and utilities in characterize the energy in terms of level of quality, but this requires the calculation of various indexes and the performing of even complex analyses. This leads to an increase of the requirements of both analogical and digital devices composing the smart meters. Great advantages from this point of view come from the availability of more and more powerful microcontrollers at low cost. Analogical devices, such as current and voltage transducers, for power quality assessment over a wide frequency range at low cost still remain a critical aspect. These paper presents an implementation of a smart meter with low cost commercial microcontroller board (Arduino), equipped with a prototype of low cost combined voltage and current transducer designed as shield for the considered microcontroller board. Simulations and experimental characterization of the prototype are shown © 2014 IEEE
Direct bioethanol fuel cells
No full textBiomass can be stored and converted into any form of energy. Hydrogen is a 'clean' energy source: its combustion produces only water and energy. A new, eco-friendly reservoir of hydrogen is required to achieve clean and sustainable energy production. Ethanol is a suitable biofuel in this respect, being easy to produce and safe to handle, transport and store. Bioethanol plays an important role as a promising renewable energy source due to its useful properties; it can also be converted to hydrogen-rich gas through a simple reforming process, and is potentially ideal for molten carbonate fuel cells (MCFCs). © 2014 Woodhead Publishing Limited All rights reserved
Grid integration of distributed energy resources: Technologies, potentials contributions and future prospects
No full textIn the last years, technological innovations and changing economic and regulatory environments have resulted in a great interest for Distributed Generation (DG). DG concept covers local power generation at distribution level by using renewable or non-conventional generators. Distributed Energy Resources (DER) range from CHP (combined heat and power) systems based on Stirling engines, fuel cells and microturbines, to renewables like solar photovoltaic (PV) systems, wind energy conversion systems (WECS) and small scale hydroelectric generation. The use of biofuels and application of various storage technologies are also considered part of DG. In this paper, the state of the art of DG technologies and strategies - focusing on solar PV, wind and fuel cells - are analysed, benefits and drawbacks are discussed, future R&D prospects are presented. © 2013 IEEE
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