Optimisation of electricity energy markets and assessment of CO2 trading on their structure : a stochastic analysis of the greek power sector

Power production was traditionally dominated by monopolies. After a long period of research and organisational advances in international level, electricity markets have been deregulated allowing customers to choose their provider and new producers to compete the former Public Power Companies. Vast changes have been made in the European legal framework but still, the experience gathered is not sufficient to derive safe conclusions regarding the efficiency and reliability of deregulation. Furthermore, emissions' trading progressively becomes a reality in many respects, compliance with Kyoto protocol's targets is a necessity, and stability of the national grid's operation is a constraint of vital importance. Consequently, the production of electricity should not rely solely in conventional energy sources neither in renewable ones but on a mixed structure. Finding this optimal mix is the primary objective of the study. A computational tool has been created, that simulates and optimises the future electricity generation structure based on existing as well as on emerging technologies. The results focus on the Greek Power Sector and indicate a gradual decreasing of anticipated CO2 emissions while the socioeconomic constraints and reliability requirements of the system are met. Policy interventions are pointed out based on the numerical results of the model. (C) 2010 Elsevier Ltd. All rights reserved

Measurement of the Absolute Differential Cross Section for np Elastic Scattering at 194 MeV

A tagged medium-energy neutron beam has been used in a precise measurement of the absolute differential cross section for np back-scattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with 1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.Comment: 22 pages, 21 figures, submitted for publication in Physical Review

The application of reliability methods in the design of stiffened FRP composite panels for marine vessels

The use of composite laminate materials has increased rapidly in recent years due to their excellent strength to weight ratio and resistance to corrosion. In the construction of marine vessels, stiffened plates are the most commonly used structural elements, forming the deck, bottom hull, side shells and bulkheads. This paper presents the use of a stochastic approach to the design of stiffened marine composite panels as part of a current research programme into developing stochastic methods for composite ship structures, accounting for variations in material properties, geometric indices and processing techniques, from the component level to the full system level. An analytical model for the solution of a stiffened isotropic plate using a grillage analogy is extended by the use of equivalent elastic properties for composite modelling. This methodology is applied in a reliability analysis of an isotropic (steel) stiffened plate before the final application for a reliability analysis for a FRP composite stiffened plate

Pricing Carbon for Electricity Generation: National and International Dimensions

In this paper, which forms a chapter in the forthcoming Book “Delivering a Low Carbon Electricity System: Technologies, Economics and Policy”, Grubb and Newbery examine how carbon for electricity generation should be priced. They begin by suggesting that it is not clear what the correct price of carbon is, but that it spans the whole range of economically plausible prices. They then go on to discuss the theoretical merits of taxes versus quotas, concluding that theoretically a stable tax would best reflect the true social cost of emissions, which should not change with market conditions. They then go to evaluate the EU Emissions Trading Scheme where allowances for the emission of CO2 are traded (EUAs). The price signals offered by the scheme in its first trading period have been very unsatisfactory with high variability and the price trending down towards very low levels as it has become clear that governments were much too generous in their initial allocation of quotas. What is needed is a stable investment environment for low carbon generation investments. They discuss a number of policy options to achieve this: long period commitments on quotas; allowing unconstrained banking and borrowing of EUAs over multiple periods; long term price declarations to be used in allocation auctions; government issued contracts for differences on the future carbon price; or simply to issue low-carbon electricity contracts. The authors conclude with a discussion of the scope for international agreements on carbon emissions reduction. They conclude that imperfect though it is the EU ETS is a good place to start to link up emerging trading regimes, and that quota systems have more of a chance of commanding international agreement at least initially. However any international climate change agreement will be difficult to establish

Simultaneous tolerance synthesis for manufacturing and quality.

Tolerance synthesis attempts to minimize the manufacturing cost of a product by specifying an optimal set of tolerances without compromising product performance. Concurrent engineering is a new approach in product design. Tolerancing is a bridge among design, manufacturing and quality engineers and plays a key role in concurrent engineering. Since cost and quality are fundamental product issues, simultaneous tolerance synthesis for manufacturing and quality is an excellent way to implement concurrent engineering. In this thesis, a new tolerance synthesis method, Simultaneous Tolerance Synthesis for Manufacturing and Quality (STSMQ), is presented. A nonlinear optimization model is constructed to implement this method. In this model, the manufacturing cost and quality loss are combined together into a single objective function. Both process tolerance and design tolerance are chosen as decision variables. The manufacturing cost decreases as tolerance is loosened while the quality loss increases as tolerance is loosened. The purpose of this model is to balance both manufacturing cost and quality loss to achieve optimum design tolerances and process tolerances under the minimum total cost of manufacturing and quality loss. A procedure of implementation of this model is also included. The proposed method is tested by some examples. The results show that a significant reduction in total cost in manufacturing and quality loss is obtained compared to other techniques.Dept. of Industrial and Manufacturing Systems Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .Y4. Source: Masters Abstracts International, Volume: 43-05, page: 1791. Adviser: F. Salustri. Thesis (M.A.Sc.)--University of Windsor (Canada), 1999

The Question of Generation Adequacy in Liberalised Electricity Markets

This paper presents an overview of the reasons why unregulated markets for the production of electricity cannot be expected to invest sufficiently in generation capacity on a continuous basis. Although it can be shown that periodic price spikes should provide generation companies with sufficient investment incentives in theory, there are a number of probable causes of market failure. A likely result is the development of investment cycles that may affect the adequacy of capacity. The experience in California shows the great social costs associated with an episode of scarce generation capacity. Another disadvantage is that generation companies can manipulate price spikes. This would result in large transfers of income from consumers to producers and reduce the operational reliability of electricity supply during these price spikes. We end this paper by outlining several methods that have been proposed to stabilise the market, which provide better incentives to generation companies and consumers alike.Generation adequacy, Liberalised electricity market

Model, Model on the Screen, What's the Cost of Going Green?

How much a policy is expected to cost and who bears the brunt of that cost play a significant role in the debates that shape regulations. We do not have a good track record of predicting costs and their ultimate distribution, but systematic reviews of past assessments have identified some of the factors that lead to errors. A wide range of expected costs of climate policy have been hotly debated, but all are likely to be wrong. This does not mean that we should continue a debate using ill-informed analyses. On the contrary, we need early small experiments to shed light on key unknowns. Environmental stewardship is a long-term challenge and an adaptive regulatory approach promises to inform policy targets and improve controls through sequential regulatory phases that promote: innovation, flexibility and diffusion of best technologies.cost estimation, climate policy, modeling, adaptive management

Reliability-based load management of the Red Deer River bridge

This thesis presents the results of an investigation into the evaluation of a selected test bridge using instrumentation to obtain site-specific factors contributing to the evaluation, with the ultimate objective of improving the estimate of the bridge’s reliability in order to assess allowable loading more accurately. The experimental portion of the research program involved instrumenting the test bridge with strain gauges, and recording field measurements using two forms of loading. The analytical portion of the research program involved the analysis of the bridge in the as-designed state, based on the design drawings and specification, followed by a re-analysis of the bridge using the site-specific factors measured on-site. The bridge was evaluated using methods outlined in the Canadian Highway Bridge Design Code CAN/CSA-S6-00 (CSA 2000). The test bridge is located near the community of Hudson Bay, Saskatchewan. The bridge is constructed of steel-reinforced concrete, and there are three, three-span arch-shaped girders. There are also external steel bars added after initial construction to increase the midspan bending moment resistance. In total, 45 strain gauges were placed on the middle spans of the three girders to record strain induced by two forms of loading: controlled loading, in which a truck of known weight and dimensions was driven over the bridge in a number of pre-determined configurations, and in-situ loading, in which normal truck traffic was used. The current allowable loading on the bridge is a gross vehicle weight of 62.5 t, although increasing the allowable loading to 110 t has been proposed, along with two strengthening alternatives to make this increased loading feasible. To provide a base-line analysis for comparison purposes, the bridge was first evaluated based strictly on information taken from the design drawings and specifications. The evaluation was performed using the load and resistance factor method, in which load and resistance factors were used to account for uncertainty, as well as by the mean load method, in which statistical properties of the variable’s parameters included in the design were used to account for uncertainty. The result of the load and resistance factor method was a live load capacity factor, indicating the overall “rating” of the bridge. In addition to the live load capacity factor, the mean load method was also used to determine the reliability index. The results of the as-designed analysis showed that the mean load method gave more conservative estimates of the bridge capacity. Furthermore, it was determined that, based on these assessments, the bridge would not have sufficient capacity to carry the proposed 110 t truck loads.The bridge was re-evaluated using site-specific factors with the mean load method. Using the measured strains, statistical parameters were determined for live load effects, distribution factors, dynamic load allowance, and resistance. Statistical parameters that could not be obtained readily through testing were obtained from the literature. The results indicated that code-predicted estimates of a number of factors were highly conservative. Flexural and shear load effects in the girders were found to be less than 15% of the theoretical predictions, as a result of apparent arching action in the girders, generating significant axial forces. For this arching action to occur, horizontal restraint was required at the supports, either through unanticipated restraint in the bearings, or tension tie action of the tensile girder reinforcement. Furthermore, the dynamic amplification was found to be less than 1.0. The resulting reliability indices indicated that the bridge would be safe under the proposed increased allowable loading (110 t). Finite element models were used to confirm the dynamic amplification observations and examine the effects of different degrees of bearing restraint. The model showed results similar to those measured for dynamic amplification. It was found that if the bearings were to become completely fixed against horizontal translation, the bridge would become overloaded as a result of increased shear effects, demonstrating the need for proper bearing maintenance. An analysis of relative costs was completed to determine the most cost-effective solution for hauling logs. Assumptions were made regarding truck and maintenance and operating costs. The results indicated that the most economic solution was to use the method outlined in the research to increase the allowable loading on the bridge to 110 t, over the strengthening alternatives and simply leaving the bridge in the current state

Psychometrics in Practice at RCEC

A broad range of topics is dealt with in this volume: from combining the psychometric generalizability and item response theories to the ideas for an integrated formative use of data-driven decision making, assessment for learning and diagnostic testing. A number of chapters pay attention to computerized (adaptive) and classification testing. Other chapters treat the quality of testing in a general sense, but for topics like maintaining standards or the testing of writing ability, the quality of testing is dealt with more specifically.\ud All authors are connected to RCEC as researchers. They present one of their current research topics and provide some insight into the focus of RCEC. The selection of the topics and the editing intends that the book should be of special interest to educational researchers, psychometricians and practitioners in educational assessment