4,974 research outputs found

    Is combination of nodal pricing and average participation tariff the best solution to coordinate the location of power plants with lumpy transmission investments?

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    This paper evaluates the opportunity and efficiency to introduce a two-part tariff to coordinate the location of power plants with lumpy transmission investments. Nodal pricing sends the short run component of such a two-part tariff and we study the case where the average participation tariff sends the long run one. We argue that this solution is helpful because the average participation tariff tackles lumpiness of transmission capacity while being as cost-reflective as possible. Our proposition is evaluated based on a double optimization model where a TSO minimizes the transmission cost while a generator minimizes its own cost that may take into account network constraints and include the average participation tariff. Numerical simulations are performed on a two-node network evolving during twenty years with increasing demand. The joint implementation of nodal pricing and the average participation tariff stays the best combination to coordinate as efficiently as possible the generation and transmission investments, although the optimal set of generation and transmission investments may not be reached because of transmission lumpiness. The simulations show also that implementing locational network tariffs is prioritary over implementing nodal pricing to coordinate more efficiently the location of generation with lumpy transmission investment. In the considered examples, the average participation tariff allows a more efficient location of generation even when the congestion management scheme being redispatch sends no short run locational signal.Generation investment; Lumpy transmission investment; Long run coordination; Locational signals; Efficiency evaluation

    Precipitation of niobium carbonitrides in ferrite: chemical composition measurements and thermodynamic modelling

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    High-resolution transmission electron microscopy and electron-energy loss spectroscopy have been used to characterize the structure and chemical composition of niobium carbonitrides in the ferrite of a Fe–Nb–C–N model alloy at different precipitation stages. Experiments seem to indicate the coexistence of two types of precipitates: pure niobium nitrides and mixed substoichiometric niobium carbonitrides. In order to understand the chemical composition of these precipitates, a thermodynamic formalism has been developed to evaluate the nucleation and growth rates (classical nucleation theory) and the chemical composition of nuclei and existing precipitates. A model based on the numerical solution of thermodynamic and kinetic equations is used to compute the evolution of the precipitate size distribution at a given temperature. The predicted compositions are in very good agreement with experimental results

    The role of transmission investment in the coordination between generation and transmission in the liberalized power systems

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    This paper examines how transmission coordinates with generation to the long term in a liberalized power system. We rely on a modular analysis to separate the mechanisms of coordination between generation and transmission of electricity into distinct modules. The governance structure of transmission completes this analysis framework. We then show that in a logic of complementarity, this governance structure influences the options that TSO implements to manage effectively power flows. Although locational signals are necessary to guide the installation of new power plants, the governance structure explains that investment in network may be the only effective method of longterm coordination between generation and transmission.The diversity of design of TSOs

    Anticipation for Efficient Electricity Transmission Network Investments

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    This paper proposes a model and preliminary results to evaluate the efficiency of anticipating the connection of power plants with shorter construction duration than the time needed to obtain the right to upgrade the network and finally to do this reinforcement. This evaluation is made in presence of a cost of anticipation related to the study of the project of network investment and to the administrative procedures needed to obtain the building agreement. This model compares a proactive TSO that anticipates the connection of new generators and then the required network reinforcement, with a reactive one that does not make any anticipation but that may then face greater congestion while the network is being reinforced. The efficiency of these behaviors is measured in terms of social cost. We find out that there exists a limit of probability for the connection of generators beyond which a proactive TSO is more efficient than a reactive one. Evaluated on a realistic case of connection, this limit of probability is found quite low, which indicates that the proactive behavior for a TSO shall generally be the optimal one.

    The role of transmission investment in the coordination between generation and transmission in the liberalized power systems

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    This paper examines how transmission coordinates with generation to the long term in a liberalized power system. We rely on a modular analysis to separate the mechanisms of coordination between generation and transmission of electricity into distinct modules. The governance structure of transmission completes this analysis framework. We then show that in a logic of complementarity, this governance structure influences the options that TSO implements to manage effectively power flows. Although locational signals are necessary to guide the installation of new power plants, the governance structure explains that investment in network may be the only effective method of longterm coordination between generation and transmission.

    Topological susceptibility and Instanton size distribution from over-improved cooling

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    We measure the topological susceptibility by cooling with an over-improved action. In contrast with usual cooling, large instantons survive over-improved cooling {\em indefinitely}. By varying the parameter of the over-improved cooling action, we measure the instanton size distribution.Comment: 4 uuencoded PostScript pages, contribution to LAT95 (fig.2 simplified to conserve space; available upon request

    The role of transmission investment in the coordination between generation and transmission in the liberalized power systems

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    This paper examines how transmission coordinates with generation to the long term in a liberalized power system. We rely on a modular analysis to separate the mechanisms of coordination between generation and transmission of electricity into distinct modules. The governance structure of transmission completes this analysis framework. We then show that in a logic of complementarity, this governance structure influences the options that TSO implements to manage effectively power flows. Although locational signals are necessary to guide the installation of new power plants, the governance structure explains that investment in network may be the only effective method of longterm coordination between generation and transmission.

    The diversity of design of TSOs

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    It is puzzling today to explain diversity and imperfection of actual transmission monopoly designs in competitive electricity markets. We argue that transmission monopoly in competitive electricity markets has to be analysed within a Wilson (2002) modular framework. Applied to the management of electricity flows, at least three modules make the core of transmission design: 1° the short run management of network externalities; 2° the long run management of network investment; and 3° the coordination of neighboring Transmission System Operators for cross border trade. In order to tackle this diversity of designs of TSOs, we show that for each of these modules, three different basic ways of managing them are possible. Among the identified twenty seven options of organisation, we define an Ideal TSO. Second, we demonstrate that 1°monopoly design differs from this Ideal TSO and cannot handle these three modules irrespective of the “institutional” definition and allocation of property rights on transmission; while 2°definition and allocation of property rights on transmission cannot ignore the existing electrical industry and transmission network structure: they have to complement each other to be efficient. Some conclusions for regulatory issues of transmission systems operators are derived from this analysis of network monopoly organisation.design of TSOs; management of power flows; governance structure of transmission
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