[en] The capacity credit of wind plant is of continuing interest. This paper examines the principles behind assessments of capacity credits and notes variations in methodology. It also sets out to resolve some apparent anomalies. However, broadly speaking, values, of capacity credit are not generally transferable from one power system to another. Suggestions for simplified methods of estimating credits are made and clarification of nomenclature is advocated. (author)

[en] Quantitative approaches have been used for the assessment of undiscovered uranium resources in geological investigation units of Argentina with the highest uranium potential at the current knowledge level. Applications of the McCammon and Deposit Size Frequency (DSF) methods are described in detail using the San Rafael basin investigation unit as example, but are applied as well to Paganzo basin, Pampean Ranges, Salta Group basin and Chubut basin. (author)

[en] Market, demand and production of uranium in the world constitutes the essential of this work. (N.C.)

[en] The paper examines the problems of linear optimization with the introduction of risks in the allocation of resources among a finite number of consumers. Risk is seen as a product of a resource and the probability for an adverse event in the allocation of that resource. Resources and risks are considered variables between which there are linear constraints. The aim is to minimize the costs of allocating resources and the insurance against the involved risks. Implementing such minimization separately for the resources and the risks solves two separate linear optimization problems, but there is a disruption in the relationship between the resources, the risks, and the probability for adverse events. The paper proposes a method in which, through an appropriate modification of variables and coefficients, a linear optimization of the costs is performed simultaneously both by the resources and by the risks, subject to all constraints and relations between resources, risks and the likelihood of adverse events. A numerical example is solved by applying the proposed method based on a linear optimization with modified variables and coefficients, consistent with linear constraints and requirements for the relations between the resources, the risks, and the probabilities of adverse events. This example shows the possibilities for practical application of the proposed method. Key words: linear optimization, resources, risks, adverse events probabilities, total costs minimization

[en] Multilateral Development Agencies (MDAs) have been emerging as responsible for the widespread of Strategic Environmental Assessment (SEA) application in low and middle income countries. However, the effectiveness of SEA, as practiced by MDAs, has received limited attention in literature so far. This paper aims to analyse the use of SEA by MDAs in the context of loan agreements established between these countries. Based on documentation gathered in public databases, six energy related cases were reviewed in relation to the moment that SEA started, the strategic dimensions of proposed actions, compliance with key aspects of SEA, and also to the quality of SEA reports. Results indicate a number of aspects that should be improved in order to increase SEA effectiveness: SEA is starting after relevant decisions, is applied to actions without clear definition of strategic dimensions and lacks a systematic assessment of alternatives. Regarding the quality of SEA reports, the outcomes reveal a poor quality in baseline description, development and assessment of alternatives and public participation. - Highlights: • MDAs are fostering the use of SEA in developing countries. • SEA is applied late by MDAs and needs to enhance its strategic dimensions. • ToRs and SEA reports needs to better comply with key aspects of SEA • We've found no evidences that SEA applied by MDAs is contributing to better decisions.

[en] Under the combined effect of various factors, such as interrogations related to facing the climatic changes, the increasing prices of oil versus announced decrease of its resources, the major geopolitical evolution and the remarkable development of Asia, we live nowadays a revival of nuclear power in the very front of stage. In tis context, the following question is posed: could the nuclear fission be a sustainable source of energy when taking into consideration the availability of uranium resources? The article aims at pinpointing the knowledge we have about the world uranium resources, their limits of uncertainty and the relation between knowledge resources and market evolution. To conclude, some susceptible tracks are proposed to improve the using process of uranium resources particularly in softening the impact of high prices

[en] OPEC's World Energy Model, OWEM, is used to develop the outlook for oil demand and supply to 2020. The reference case assumes world economic growth averaging 3.3 per cent per annum, while OPEC's Reference Basket of seven crudes remains mainly in the target range of US $22-28 a barrel, in nominal terms. With no additional assumed policy measures, for example, to reduce CO₂ emissions, the reference case sees world oil demand rising from 76 million barrels a day in 2000 to 89 mb/d in 2010 and 107 mb/d in 2020. More than three-quarters of this increase comes from developing countries. The most important sector for a demand increase is transportation, accounting for 60 per cent of the rise globally. On the supply side, the oil resource base is not considered a constraint to satisfying this increase in demand. Non-OPEC production is expected to continue to grow during the current decade, and to stabilise at a level of 53-55 mb/d beyond 2010. OPEC production is projected to reach 36 mb/d by 2010 and 52 mb/d in 2020. It is important, however, to recognise the uncertainties pervading such an assessment. For example, it is not clear how future economic growth, energy policies and technology will develop over this time horizon, and this inevitably clouds any assessment of future oil demand and supply. In an attempt to quantify one aspect of such uncertainty, other feasible economic growth rates have been assumed, the results of which suggest that OPEC output by 2010 could be 4-5 mb/d higher or lower than in the reference case, while the range is clearly even greater in the years to 2020. Moreover, policy reactions to such developments could compound the uncertainty. On the other hand, such alternative economic growth could place pressure upon oil prices to move outside OPEC's price band of $22-28/b. These uncertainties illustrate the scope of the challenges confronting the oil industry, especially given the long lead-time nature of oil industry investment, in making economically sound investment decisions that are geared to ensuring that sufficient capacity exists. Market stability, at reasonable and sustainable prices, is a key prerequisite for rising to these challenges, and, since market forces alone are not enough to guarantee this, a broad base of cooperative efforts will be needed to increase the chances of meeting this fundamental objective. (author)

[en] It is shown that reserves to production ratio, R/P, which optimizes development and maximizes present value, can be estimated using an equation containing the four variables of well initial production; rate, well costs, netback prices and discount rate. A sensitivity analysis of the optimization equation indicates that well costs and well productivity have the most influence on the optimum R/P. Improvements in technology beneficially affect well productivity and reduce costs, hence reducing capital requirements and producing an economic incentive to produce at low R/Ps. The influence of gas prices is considered less significant, but the expected increases in gas prices in the Western Canadian Sedimentary Basin will also act an an incentive to produce at low R/Ps. Recent gas discoveries in the Basin have been single well pools with high productivity and limited areal extent, which produce at low R/Ps. Continuation of this trend will cause further decrease in R/Ps. While this study assumed maximizing present value as the most likely objective, it is possible that regulators and producers have other objectives. It would be reasonable to expect that these alternative objectives will also favour producing at high rates and at low R/Ps. 2 tabs., 13 figs

[en] In this study changes in the surface pressure field over Europe are analysed to see if they are reflected in the statistical structure of the wind field over the Great Hungarian Plain. The data base consists of hourly wind speed data of three meteorological stations (Debrecen, Bekescsaba and Szeged) at the Great Hungarian Plain, coming from the periods between 1968-72 and 1991-95, respectively. A new statistical test is also shown in the paper, in order to apply it for determining significance of statistical differences between expected values of non-independent time series. Decrease of wind energy might be expected at the Great Hungarian Plain, however no definite results were obtained on the data base considered. (author)

[en] Since inventories have a lower bound or a minimum operating level, economic literature suggests a nonlinear relationship between inventory level and commodity prices. This was found to be the case in the short-run crude oil market. In order to explore this inventory-price relationship, two nonlinear inventory variables are defined and derived from the monthly normal level and relative level of OECD crude oil inventories from post 1991 Gulf War to October 2003: one for the low inventory state and another for the high inventory state of the crude oil market. Incorporation of low- and high-inventory variables in a single equation model to forecast short-run WTI crude oil prices enhances the model fit and forecast ability. (author)