9,314 research outputs found

    Factory modelling: data guidance for analysing production, utility and building architecture systems

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    Work on energy and resource reduction in factories is dependent on the availability of data. Typically, available sources are incomplete or inappropriate for direct use and manipulation is required. Identifying new improvement opportunities through simulation across factory production, utility and building architecture domains requires analysis of model feasibility, particularly in terms of system data composition, input resolution and simulation result fidelity. This paper reviews literature on developing appropriate model data for assessing energy and material flows at factory level. Gaps are found in guidance for analysis and integration of resource-flows across system boundaries. The process for how data was prepared, input and iteratively developed alongside conceptual and simulation models is described. The case of a large-scale UK manufacturer is presented alongside discussions on challenges associated with factory level modelling, and the insights gained from understanding the effect of data clarity on system performance

    Beggar Thy Neighbour Exchange Rate Regime Misadvice  from Misapplications of Mundell (1961) and the Remedy

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    Economists invoke Mundell (1961) in arguing for the general policy of   a flexible exchange rate regime as a means of restoring equilibria   after shocks. But there is a discrepancy between the intent of the   general policy and attempts at its implementation as identified by   specific changes in exchange rates.  When we assemble the set of   specific changes called for by distinct economists operating as   advocates for individual countries, these are uniformly in the form   of beggar-thy-neighbour advice – ie travesties of objectively   identifying disequilibria and a menace to international cooperation   and peace.  This paper traces the unintended travesties to problems   of complexity and uncertainty, problems that implicitly are assumed   absent in Mundell (1961) rendering the situation so simple that   equilibria are transparent.  The problems remained essentially   unaddressed when economists extended Mundell (1961) via expected   utility theory since this theory also ignores the impossibility of   maximising and the complexities of central bankers, private firms and   others in doing the evaluation stage in reaching decisions.  The   problems can be overcome by modelling within SKAT, the Stages of   Knowledge Ahead Theory.  This paper points to experimental evidence   in support of the view that under all sorts of disequilibrating   shocks, currency unions outperform flexible currencies by eliminating   the inefficiencies generated by exchange rate uncertainty.optimal currency area; exchange rate regime; certainty effects;   policy; beggar-thy-neighbour; SKAT the Stages of Knowledge Ahead Theory; complexity; equilibrium; small world; shocks; expenditure-switching shocks; supply-side shocks; demand shocks; experiment, safety, international competitiveness.

    Hazard and risk assessment for indirect potable reuse schemes: An approach for use in developing Water Safety Plans

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    This is the post-print version of the final paper published in Water Research. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.This paper describes research undertaken to develop an approach for facilitating an initial hazard assessment and risk characterisation for a proposed indirect potable reuse scheme, as part of the water safety plan recommended by the World Health Organization. The process involved a description and evaluation of the catchment, which was the sewerage system supplying the sewage treatment works that would provide the effluent to supply the pilot scale indirect potable reuse water treatment plant. Hazards, sources and barriers throughout the proposed system were identified and evaluated. An initial assessment of the possible hazards, highlighted chemical hazards as predominating, and assessment of risks, using a heat map as output, categorised most hazards as medium or high risk. However, this outcome has been influenced by a precautionary approach which assigned a high likelihood to the occurrence of hazards where no data was available on their occurrence in the system. As more data becomes available, and the waster safety plan develops, it is anticipated that the risk heat map will become more specific. Additionally, high quality targets, to drinking water standards, have been set, although water from the potable reuse plant will be discharged to receiving waters where it will undergo natural attenuation prior to further treatment to potable standards before distribution. The assessment has demonstrated the usefulness of the approach where data is initially limited, in generating a heat map allowing for prioritisation of hazards to a practical level.Thames Water Utilities Ltd and Mexican Consejo Nacional de Ciencia y Tecnologıa

    Managed Floats to Damp Shocks like 1982-5 and 2006-9: Field and Laboratory Evidence for Chinese Interest in a Single World Currency

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    This paper’s field evidence is: (1) many official sectors rapidly forget the damage of the 1982-85 exchange rate liquidity crisis and reverted to what caused that crisis, namely a closed economy clean floats perspective; and (2) the 2006-2008/9 exchange rate liquidity shock would have been more drastic but for central bank currency swaps. This evidence is bolstered by a laboratory experiment that incorporates more aspects of real world complexity and more different sorts of official and private sector agents than are feasible in econometric or algebraic investigations and employs a new central bank cooperation-conflict model of exchange rate determination , and is within an umbrella theory of Pope, namely SKAT, the Stages of Knowledge Ahead Theory. SKAT allows for risk effects from stages omitted in normal models, including those from (a) difficulties of agents in evaluating alternatives in a complex environment in which the assumed maximization of expected utility is impossible; and (b) preference for safety and reliability is not trivialized. Our joint field plus laboratory evidence indicates that official sectors should maintain an international exchange rate oriented perspective, or better yet, a single world currency as recommended by Zhou Xiaochuan, head of the People’s Bank of China. To avoid rapid forgetting of havoc from isolationist clean floats and the value of stable exchange rates, a new syllabus, as under the SKAT umbrella, is fundamental in the education of official sector members in order to furnish them with a coherent alternative intellectual framework to current university education that excludes liquidity crises.clean float, managed float, IMF imposed conditions, exchange rate regime, exchange rate volatility, experiment, SKAT the Stages of Knowledge Ahead Theory, monetary policy, transparent policy, exchange rate shocks, central bank cooperation, central bank conflict

    Energy Management Strategies in hydrogen Smart-Grids: A laboratory experience

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    As microgrids gain reputation, nations are making decisions towards a new energetic paradigm where the centralized model is being abandoned in favor of a more sophisticated, reliable, environmentally friendly and decentralized one. The implementation of such sophisticated systems drive to find out new control techniques that make the system “smart”, bringing the Smart-Grid concept. This paper studies the role of Energy Management Strategies (EMSs) in hydrogen microgrids, covering both theoretical and experimental sides. It first describes the commissioning of a new labscale microgrid system to analyze a set of different EMS performance in real-life. This is followed by a summary of the approach used towards obtaining dynamic models to study and refine the different controllers implemented within this work. Then the implementation and validation of the developed EMSs using the new labscale microgrid are discussed. Experimental results are shown comparing the response of simple strategies (hysteresis band) against complex on-line optimization techniques, such as the Model Predictive Control. The difference between both approaches is extensively discussed. Results evidence how different control techniques can greatly influence the plant performance and finally we provide a set of guidelines for designing and operating Smart Grids.Ministerio de Economía y Competitividad DPI2013-46912-C2-1-

    Ancillary Services 4.0: A Top-To-Bottom Control-Based Approach for Solving Ancillary Services Problems in Smart Grids

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    Power systems are experiencing a large amount of renewable generation with highly stochastic and partly unpredictable characteristics. This change in energy production implies significant consequences related to the provision of ancillary services (AS). Current markets dedicated to the provision of AS are not able to benefit from the flexible energy resources. They also cannot cope with the new level of stochasticity, non-linearity and dynamics of generation and flexibility. To overcome such issues and exploit the potential of flexibility resources, a new strategy is required. In this paper, by capitalising on flexibility resources’ potential, AS 4.0 approach is proposed, which offers a comprehensive solution for the AS provision in the smart grid era

    Management of local citizen energy communities and bilateral contracting in multi-agent electricity markets

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    ABSTRACT: Over the last few decades, the electricity sector has experienced several changes, resulting in different electricity markets (EMs) models and paradigms. In particular, liberalization has led to the establishment of a wholesale market for electricity generation and a retail market for electricity retailing. In competitive EMs, customers can do the following: freely choose their electricity suppliers; invest in variable renewable energy such as solar photovoltaic; become prosumers; or form local alliances such as Citizen Energy Communities (CECs). Trading of electricity can be done in spot and derivatives markets, or by bilateral contracts. This article focuses on CECs. Specifically, it presents how agent-based local consumers can form alliances as CECs, manage their resources, and trade on EMs. It also presents a review of how agent-based systems can model and support the formation and interaction of alliances in the electricity sector. The CEC can trade electricity directly with sellers through private bilateral agreements. During the negotiation of private bilateral contracts, the CEC receives the prices and volumes of their members and according to its negotiation strategy, tries to satisfy the electricity demands of all members and reduce their costs for electricity.info:eu-repo/semantics/publishedVersio
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