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Energy policy aims to reduce emissions at least long-run cost while ensuring reliability. Its effecacy depends on the cost of emissions reduced. Britain introduced an additional carbon tax (the Carbon Price Support, CPS) for fuels used to generate electricity that by 2015 added [pounds sterling]18/t C[O.sub.2], dramatically reducing the coal share from 41% in 2013 to 6% in 2018. Policies have both short and long-run impacts. Both need to be estimated to measure carbon savings. The paper shows how to measure the Marginal Displacement Factor (MDF, tonnes C[O.sub.2] /MWh) for wind. The short-run (SR) MDF is estimated econometrically while the long-run (LR) MDF is calculated from a unit commitment model of the GB system in 2015. We examine counter-factual fuel and carbon price scenarios. The CPS lowered the SR-MDF by 7% in 2015 but raised the LR-MDF (for a 25% increase in wind capacity) by 18%. We discuss reasons for the modest differences in the SR- and LR-MDFs. Keywords: Wind, marginal displacement factors, carbon pricing, fuel mix, unit commitment model, econometrics, 1. INTRODUCTION Energy policy aims to reduce emissions at least long-run cost while ensuring reliability. Policies to support wind or solar PV, improve efficiency, or shift peak demand need to [...]

Earlier research has shown that adding wind generation to a network can lower the total annual operating cost by displacing conventional generation. At the same time, the variability of wind [...]

The potential of wind power as a global source of electricity is assessed by using winds derived through assimilation of data from a variety of meteorological sources. The analysis indicates that a network of land-based 2.5-megawatt (MW) turbines restricted to non-forested, ice-free, nonurban areas operating at as little as 20% of their rated capacity could supply >40 times current worldwide consumption of electricity, >5 times total global use of energy in all forms. Resources in the contiguous United States, specifically in the central plain states, could accommodate as much as 16 times total current demand for electricity in the United States. Estimates are given also for quantities of electricity that could be obtained by using a network of 3.6-MW turbines deployed in ocean waters with depths

Keen interest in the development and utilization of wind-based distributed generations (DGs) has been currently observed worldwide for several reasons. Among those is controlling the emission of environmentally harmful substances, limiting the growth in energy costs associated with the use of conventional energy sources and encouraging the independent power producers for participation in the electricity market system. One of the most important issues is to quantitatively assess the impact of such type of DGs on the distribution system reliability. This paper presents a probabilistic technique to evaluate the distribution system reliability utilizing segmentation concept and a novel constrained Grey predictor technique for wind speed profile estimation. Index Terms--Distributed power generation, distribution system reliability, uncertainty, wind power.

The stochastic nature of wind alters the unit commitment and dispatch problem. By accounting for this uncertainty when scheduling the system, more robust schedules are produced, which should, on average, reduce expected costs. In this paper, the effects of stochastic wind and load on the unit commitment and dispatch of power systems with high levels of wind power are examined. By comparing the costs, planned operation and performance of the schedules produced, it is shown that stochastic optimization results in less costly, of the order of 0.25%, and better performing schedules than deterministic optimization. The impact of planning the system more frequently to account for updated wind and load forecasts is then examined. More frequent planning means more up to date forecasts are used, which reduces the need for reserve and increases performance of the schedules. It is shown that mid-merit and peaking units and the interconnection are the most affected parts of the system where uncertainty of wind is concerned. Index Terms--Power generation dispatch, power system economics, stochastic systems, wind power generation.

Without storage provision, a wind energy conversion system (WECS) does not have fault ride-through capability for most temporary faults on the utility feeder. This paper proposes a hybrid valve switching and control strategy for a voltage-sourced converter (VSC) used for interfacing a WECS to the utility grid. The hybrid control of the VSC ensures continuous operation of the system in the presence of temporary single line to ground faults on the utility feeder without the need for a storage provision. The fast acting hybrid control also limits reactive fault current contribution by the converter, and therefore, avoids problems associated with overcurrent protection of the feeder. The hybrid valve switching and control of the VSC consists of: 1) sinusoidal pulse width modulation (SPWM) based valve switching and current-controlled voltage-source operation of the VSC during normal system operating conditions and 2) hysteresis space vector modulation (HSVM) based switching together with controlled current-source operation of the VSC during temporary fault conditions. The hybrid control of the VSC isolates the WECS from the grid side disturbances to ensure uninterrupted operation of the unit. Simulation studies of the grid-interactive WECS in PSCAD/EMTDC confirm the validity of the proposed hybrid control scheme. Index Terms--Hybrid control, induction generator, self-excitation, sinusoidal pulse width modulation (SPWM), space vector modulation, thyristor rectifier, voltage-sourced converter (VSC), wind energy.

This paper presents the output power control of a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG). It is assumed that the considered wind module integrates a stand-alone hybrid generation system, jointly with a battery bank, a variable ac load, and other generation subsystems. The operation strategy of the hybrid system determines two possible operation modes for the WECS, depending on the power requirements of the load and the wind availability. The paper deals with the design of a combined high-order sliding mode (HOSM) controller for the power control of the WECS on both operational modes. The main features of the obtained controller are its chattering-free behavior, its finite-time reaching phase, its simplicity, and its robustness with respect to external disturbances and unmodeled dynamics. The performance of the closed-loop system is assessed through representative computer simulations. Index Terms--High-order sliding mode (HOSM), nonlinear systems, wind energy.

Several coastal American states are exploring the benefits and challenges of harnessing strong off-shore winds as a source of cheap renewable energy. Offshore wind farms are being developed along Texas's Gulf Coast, but face political opposition and technical difficulties along the East and West coasts respectively.

In this paper, minute-to-minute wind power variations are decomposed into slow, fast, and ramp components to assess the influence of each component on power system operation. Using detailed, long-term simulation models, this paper confirms that most power systems can absorb the impacts of wind power variations with little difficulty. Yet, since ramps in wind power and system demand could coincide, systems with limited ramping capabilities are at risk. It is shown that extending simulation models to include load dynamics and automatic generation control (AGC) time delays do not alter these conclusions. This paper also discusses wind penetration approaches and control area performance measures, linking the latter to the placement of the wind farms within the interconnection. Index Terms--AGC model, automatic generation control (AGC), long-term dynamic model, penetration limit, system dynamic response, wind events, wind farm model, wind power.

Following several governmental policies trying to reduce C[O.sub.2] emissions, renewable energies have been largely promoted during the last decade. Among the green energies that have been developed, wind can actually be seen as one of the most promising solution if we refer to its past and predicted evolutions. However and, even though wind can be considered as an interesting alternative to fossil fuels, it is imperious to emphasize on problematic situations that could be due to the intermittent behavior of wind generation. Indeed, actually, most of the electric utilities do not consider wind power in the classical units management; consequently involving, in the case of increased wind powder penetration, untimely stopping of big thermal (or nuclear) units. It is, therefore, necessary to calculate wind equivalent capacities in order to introduce a coherent evaluation of wind production in the management of the centralized production park. In this paper, wind equivalent capacities are calculated using a Non Sequential Monte Carlo Simulation. Moreover, in order to evaluate the importance of the wind correlation level between parks located in the same geographical region, two cases are investigated, respectively considering entirely correlated wind parks and, on the opposite, totally independent wind sites. Finally, simulation results show that durations of simultaneous zero wind power production for each considered wind parks stay, in both cases, very low involving quasi-identical calculated equivalent capacities; what tends to demonstrate the minor importance of the wind parks correlation level for wind power estimation in reliability studies. Note that, here, the proposed conclusions are obtained using the Belgian production park data and that the objective is not to dynamically estimate wind production on the short-term (by the use of an autocorrelation function) but rather to give a simplified way to introduce an hourly evaluation of wind production in the day by day management of the classical thermal (nuclear) units. Index Terms--Power system modeling, Weibull distributions, wind energy.

In this paper, the impact of the response of a wind farm (WF) on the operation of a nearby grid is investigated during network disturbances. Only modern variable speed wind turbines are treated in this work. The new E.ON Netz fault response code for WF is taken as the base case for the study. The results found in this paper are that the performance of the used Cigre 32-bus test system during disturbances is improved when the WF is complying with the E.ON code compared to the traditional unity power factor operation. Further improvements are found when the slope of the reactive current support line is increased from the E.ON specified value. In addition, a larger converter of a variable speed wind turbine is exploited that is to be used in order to improve the stability of a nearby grid by extending the reactive current support. By doing so, it is shown in this paper that the voltage profile at the point of common coupling (pcc) as well as the transient stability of the grid are improved compared to the original E.ON code, in addition to the improvements already achieved by using the E.ON code in its original form. Finally, regarding the utilization of a larger converter, it is important to point out that the possible reactive power in-feed into the pcc from an offshore WF decreases with increasing cable length during network faults, making it difficult to support the grid with extra reactive power during disturbances. Index Terms--Fault ride-through (FRT), frequency converter, grid code, grid support, reactive power control, static synchronous compensator (STATCOM), transient stability, variable speed wind turbine, voltage control.

Increasing usage wind power as alternative energy resource for decreasing carbon dioxide emissions in Vietnam is discussed.

The usage of hybrid wind-diesel power systems for electrification of remote areas of Aegean Sea islands is analyzed.

The production of wind energy via natural gas turbines and compressed air energy storage to reduce greenhouse gas emissions is analyzed.

A research analyzes how institutional conditions affect policy and planning processes for wind energy implementation in the Netherlands from the perspective of building institutional capacity for ecological modernization. The inadequate implementation is because policy community around wind power is characterized by fragmentation and mistrust due to lack of structural incorporation of public and societal stakeholders in policy-making and planning.

The energy policy of the United Kingdom government, which aims at meeting 10% of the country's energy requirement through renewable energy sources like wind power, is discussed.

Using computer simulations, the price dynamics that could appear in a market for tradable green certificates, to encourage the production of electricity from wind, are analyzed.

The positive effects of policy learning on the development of wind power sector in European countries are discussed.