1,721,077 research outputs found
Development of an ambient temperature alkaline electrolyser for dynamic operation with renewable energy sources
No full textA comparison is made between the ambient and conventional temperature alkaline electrolysers in terms of operational system, voltage efficiency and corrosion rates. The capital, operational and maintenance costs are reduced by reducing auxiliary equipment as well as auxiliary utilities in the ambient temperature alkaline electrolyser. Also, since auxiliary electricity consumption is reduced, the alkaline electrolyser is capable for dynamic, continuous and fast-response operation with renewable energy sources. The ambient temperature alkaline electrolyser is capable for wider operational range and faster response time when powered by wind energy sources. Although the voltage efficiency for hydrogen production is increased by about 12% at the conventional operating temperature, corrosion rate of the electrode is increased by a factor of about 6.3. The voltage efficiency for hydrogen production, however, is increased by about 12% by employing electrocatalyst in the ambient temperature alkaline electrolyser, and there is benefit of enhancing lifetime durability of the electrode as well as cell components at relatively lower operating temperatur
Improvement of power system frequency stability using alkaline electrolysis plants
Full text linkHydrogen could become an important energy carrier, in particular used as an input to fuel cell electric vehicles. Alkaline electrolysers are an attractive technology to produce carbon-free hydrogen from renewable generated electricity. Large-scale alkaline electrolysers used in future hydrogen-filling stations could also be utilised to improve the frequency stability of the electricity power system. The electrolyser load can be controlled to respond to power system frequency variations, and in the case of a sudden loss of generation, these electrolysers could rapidly decrease their load on the system to maintain the power balance. In this study, the potential of alkaline electrolysers to dynamically stabilise the frequency of the power system is assessed. A model of steam turbine generation unit has been developed in MATLAB SIMULINK environment, and a scenario in which there is a sudden loss of generation in the system is examined. It is demonstrated that alkaline electrolysers could prevent unacceptable frequency drop, i.e. below the statutory limit, following by an abrupt loss of generation, even with no spinning reserve on the system. In this article for the first time, the ramping rate of an alkaline electrolyser is shown through experimental data. <br/
The impact on the electrical grid of hydrogen production from alkaline electrolysers
No full textIn the next 50 years, it is possible that hydrogen could become widely used as a fuel for transport. The result of this change could increase energy security and reduce environmental impacts, such as CO2 emissions. Hydrogen produced by electrolysers could be used in Fuel Cell Vehicles (FCVs) with no direct harmful emission. In this research a scenario involving the widespread availability of Hydrogen at UK fuel stations for the purpose of supplying all vehicles is investigated. Calculations have been carried out to find out how much Hydrogen is needed for road transportation in the UK to be met in this way. The electrolysers will be assumed to be able to follow supply, i.e. their electricity consumption can be adjusted to follow changes in renewable energy generation in the power system. In this way these new electrolyser loads can be used for demand side management, facilitating the introduction of high volumes of renewable energy generation (mainly wind energy) to the power system. The interaction between the electrolysers and the network is investigated through modelling using MATLAB software
Design of a system to investigate the performance of alkaline electrolysers during operation with intermittency of wind power
No full textDemonstration of the operation and performance of a pressurised alkaline electrolyser operating in the hydrogen fuelling station in Porsgrunn, Norway
No full textOperation of the hydrogen filling station at Herøya, Porsgrunn, Norway is reported and analysed in this paper. A 12 bar(g) pressurised alkaline electrolyser with a nominal load of 24 kW provides hydrogen for this filling station and is designed to work with time variable power from renewable resources. Two wind turbines rated at 6 kW each and two solar panels rated at 2.5 kW each are available on site to provide the power for hydrogen production which can then be used to supply a number of fuel cell and modified Internal Combustion Engine (ICE) vehicles. The station has a hydrogen storage capacity of 6.3 m3 in pressurised tanks at 450 bar(g).As a part of the authors’ experimental work, operational data and the characteristics of the pressurised alkaline electrolyser installed at the site under different operational modes have been collected and analysed. The archival value of this paper is the presentation and discussion of the electrolyser characteristics which are relevant to the identification of an acceptable control strategy to integrate such electrolyser loads within the power system and thus provide improved performance of the power system when exposed to the highly time variable energy supply from renewable sources.<br/
Utilisation of alkaline electrolysers to improve power system frequency stability with a high penetration of wind power
No full textControlling the frequency of power systems with high wind power penetration is more difficult due to the high variability of the wind power. One possible mainstream energy carrier in the future, particularly for the transportation sector, is Hydrogen, and water electrolysis is one of the most attractive ways to produce it.In this work, a detailed model of a steam turbine generator has been produced in MATLAB Simulink and used to investigate a scenario in which there is a 25% penetration of wind power. To improve the frequency stability of the power system, large scale alkaline electrolysers used in future Hydrogen filling stations could adjust their load with respect to the frequency deviation from nominal and can significantly reduce fluctuations in system frequency. For the case examined, five times less spinning reserve is required in order to maintain the power system frequency within operational limits when electrolysers are utilized as a form of demand side management (DSM), compared to the base case where no electrolyser DSM plant is available. Actual operational data from a pressurised alkaline electrolyser is used to evidence the fast load changing capability of such electrolysers.<br/
Utilisation of alkaline electrolysers in existing distribution networks to increase the amount of integrated wind capacity
Full text linkHydrogen could become a significant fuel in the future especially within the transportation sector. Alkaline electrolysers supplied with power from renewable energy sources could be utilised to provide carbon free hydrogen for future hydrogen filling stations supplying Hydrogen Fuel Cell Vehicles (HFCV), or Internal Combustion Engines (ICEs) modified to burn hydrogen. However, there is a need to develop and use appropriate strategies such that the technology delivers greater economic and environmental benefits
Development of new materials for alkaline electrolysers and investigation of the potential electrolysis impact on the electrical grid
No full textThis paper discusses development of new materials for alkaline electrolysers and assesses the impact of large penetrations of electrolysis plants on the electrical grid.New electrolyser electrodes were produced by a synthesis method of Nickel electroplated with carbon catalyst consisting of Molybdenum-Resorcinol-Formaldehyde (Mo RF), and carbon aerogel of surface area >700 m2/g and pore size of 4 nm, followed by an impregnation of molybdenum as a catalyst before deposition on nickel thus creating Ni–Mo RF electrodes. Another electrode made from Vulcan-Carbon-Platinum powder was used to produce Ni–C–Pt electrodes. The different electrodes were compared by analysis of kinetic reaction measurements using polarisation techniques and electrochemical impedance methods.An experiment was carried out to measure the AC and DC harmonics and the efficiency of the electrical parts of an operational 1 Nm3/hr electrolyser. In addition, the power system impact analysis of two Alkaline Electrolysis plants connected to the IEEE30 standard power system model was studied in MATLAB environment.<br/
Evaluation of Raney nickel electrodes prepared by atmospheric plasma spraying for alkaline water electrolysers
No full textThe work describes the evaluation of Raney nickel electrodes prepared by the technique of atmospheric plasma spraying (APS). The APS Raney nickel layers of 30 mm, 100 mm and 300 mm thicknesses were characterised prior to and post-chemical activation by SEM. Following further electrochemical activation, the performance of these layers towards hydrogen evolution reaction (HER) were evaluated using potentiodynamic Tafel analysis and electrochemical impedance spectroscopy (EIS) in 30% KOH solutions over the temperature range 30 Ce80 C. Large surface area increases, in relation to smooth nickel, were obtained for these layers following activation and these were also confirmed from cyclic voltammetry measurements. The analysis of the data indicated that of the 3 thicknesses examined, the best electrocatalytic activity towards HER was obtained for 100 mm sample, with an efficiency (based on the Higher Heating Value for H2) equal to 96% at a current density of 300 mA cm2 and temperature of 70 C
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