R. J. Barthelmie, F. Murray and S. C. Pryor.

Energy Policy, Vol. 36, No. 5, May 2008, pp. 1687-1696.

In the UK market, the total price of renewable electricity is made up of the Renewables Obligation Certificate and the price achieved for the electricity. Accurate forecasting improves the price if electricity is traded via the power exchange. In order to understand the size of wind farm for which short-term forecasting becomes economically viable, we develop a model for wind energy. Simulations were carried out for 2003 electricity prices for different forecast accuracies and strategies. The results indicate that it is possible to increase the price obtained by around @$5/MWh which is about 14% of the electricity price in 2003 and about 6% of the total price. We show that the economic benefit of using short-term forecasting is also dependant on the accuracy and cost of purchasing the forecast. As the amount of wind energy requiring integration into the grid increases, short-term forecasting becomes more important to both wind farm owners and the transmission/distribution operators.; All rights reserved, Elsevier

Jyotirmay Mathur, N. Agarwal, R. Swaroop and N. Shah.

Energy Policy, Vol. 36, No. 3, Mar 2008, pp. 1212-1222.

Over the past few years, hydrogen has been recognized as a suitable substitute for present vehicular fuels. This paper covers the economic analysis of one of the most promising hydrogen production methods-using wind energy for producing hydrogen through electrolysis of seawater-with a concentration on the Indian transport sector. The analysis provides insights about several questions such as the advantages of offshore plants over coastal installations, economics of large wind-machine clusters, and comparison of cost of producing hydrogen with competing gasoline. Robustness of results has been checked by developing several scenarios such as fast/slow learning rates for wind systems for determining future trends. Results of this analysis show that use of hydrogen for transportation is not likely to be attractive before 2012, and that too with considerable learning in wind, electrolyzer and hydrogen storage technology.; All rights reserved, Elsevier

Ravindra M. Moharil and Prakash S. Kulkarni.

Electric Power Components & Systems, Vol. 36, No. 1, Jan. 2008, pp. 1-16.

The aim of the article is to study the generator system reliability analysis with wind energy penetration in the conventional grid. It presents the reliability evaluation process, which has accurately modeled the intermittent nature of wind resource. A stochastic model with hourly mean wind speed (HMWS), standard deviation and sequential Monte Carlo simulation is used for reliability analysis. Case studies based on Roy Billinton Test System (RBTS) test system are presented using wind data from two sites in Maharashtra and one Gujarat state of India. The proposed HMWS method offers advantages, such as fast convergence of the reliability indices and high efficiency, over the Weibull method.

Lennart Soder and Hannele Holttinen.

International Journal of Global Energy Issues, Vol. 29, No. 1-2, 2008, pp. 181-198.

There is a continuous discussion going on concerning the integration cost of wind power. The integration cost can, for example, be defined as the extra costs in the rest of the system when wind power is introduced, compared with the situation without wind power. The result of the studies depends on both parameters and the method used. The aim of this paper is to structure the methods in order to get some understanding on the impact of different modelling approaches. In general, it can be noted that approximations are always needed since the integration of wind power includes so many complexities including stability of power systems, grid codes, market behaviour, uncertainties and trading possibilities. All these items have to be considered in both the wind power case and in the reference case to obtain an estimation of the integration cost.

K. George and T. Schweizer.

No. , 1 Jan 2008, pp. 138.

This report details the methodology used by the U.S. Department of Energy (DOE) Wind Energy Program and the National Renewable Energy Laboratory (NREL) to calculate levelized cost of energy (COE). To demonstrate application of the methodology, it uses technology and financial assumptions developed for evaluating research and development (R&D) progress for the programs Low-Wind-Speed Technology Project (LWST). This report also demonstrates the variation in COE estimates due to different financing assumptions independent of wind generation technology. This methodology can incorporate changes in project ownership structures, financing approaches, and financial assumptions as they change in the actual market, giving DOE a way to characterize COE relative to current market conditions. COE is an important metric for both renewable energy and fossil-fuel power plants. COE refers to the plants wholesale cost of producing electricity. It is calculated from the projected annual revenues the plant would charge to cover capital costs, operating expenses, and return to debt and equity investors, over the years of its contract life.

S. Diaf, M. Belhamel, M. Haddadi and A. Louche.

Energy Policy, Vol. 36, No. 2, Feb 2008, pp. 743-754.

The sizing and techno-economical optimization of a stand-alone hybrid photovoltaic/wind system (HPWS) with battery storage is presented in this paper. The main objective of the present study is to find the optimum size of system, able to fulfill the energy requirements of a given load distribution, for three sites located at Corsica island and to analyze the impact of different parameters on the system size. The methodology used provides a useful and simple approach for sizing and analyzing an HPWS. In the proposed stand-alone system, a new concept such as the supply of wind power via a uninterruptible power supply (UPS) is introduced and therefore the energy produced by the wind generator can be sent directly to the load. In this context, an optimization sizing model is developed. It consists of three submodels; system components submodels, technical submodel based on the loss of power supply probability (LPSP) and the economical submodel based on the levelized cost of energy (LCE). Applying the developed model, a set of configurations meeting the desired LPSP are obtained. The configuration with the lowest LCE gives the optimal one. Analyzing the optimal system configurations used to satisfy the requirements of typical residential home (3kWh/day), a significant reduction in system size is observed as the available renewable potential increases leading to a considerable decrease in LCE (case of Cape corse site). The 2 days storage capacity is found to be the best for the optimal configuration with the lowest LCE. On the other hand, for low energy requirements, the LCE is found relatively high and decreases sharply with the increase in load. However, for low LPSP values, the LCE is found to rise sharply for a little increase in LPSP.; All rights reserved, Elsevier

Dominic Moran and C. Sherrington.

Energy Policy, Vol. 35, No. 5, May 2007, pp. 2811-2825.

This paper uses cost-benefit analysis to assess the economic feasibility of a large scale windfarm project, taking into account positive and negative externalities of generation. The issue of non-use value (i.e. a welfare change among those who will never visit the area and see the windfarm) is addressed with reference to the study by Bergmann et al. 2006. Valuing the attributes of renewable energy investments. Energy Policy 34, 1004-1014 , which determined a social cost of @$19.40 per household for the non-use disamenity associated with a large scale windfarm in Scotland. This paper demonstrates the extent to which this estimate affects the economic feasibility of the project. We find that for all but one of the 16 scenarios considered, the project returns a positive net present value despite the inclusion of this non-use value, thus suggesting that in these cases the windfarm delivers a net welfare gain to society.; All rights reserved, Elsevier

Monique Hoogwijk, Detlef van Vuuren, Bert de Vries and Wim Turkenburg.

Energy, Vol. 32, No. 8, Aug. 2007, pp. 1381-1402.

In this study we explore for the USA and OECD Europe (OECD Europe includes the countries that participate in the Organisation of Economic Cooperation and Development, among which Western Europe, USA and Japan) dynamic changes in electricity production, cost and CO2 emissions when intermittent electricity sources are used with increasing penetration levels. The methodology developed can be applied for both solar photovoltaic (PV) and wind energy. Here the focus of the results is on penetration of wind electricity in the electricity system as simulated in a long-term model experiment in which the electricity demand is kept constant over time. All important parameter are included in a sensitivity analysis. With increasing penetration levels the cost reduction of wind electricity caused by upscaling and technological learning is counteracted by the cost increase due to (1) the need for additional back-up capacity, (2) the need to generate wind electricity at less favourable sites, and (3) discarded wind electricity because of supply-demand mismatch. This occurs after about 20% wind electricity production as percentage of current electricity production. At this level about 500 (OECD Europe) and 750 (USA) TWhyr-1 wind electricity is absorbed in the system with the electricity demand of the year 2000. Wind electricity is found to be discarded when the production is about 55 (USA) to 10 times (OECD Europe) the present electricity produced from wind power. Beyond 30% of present electricity production, cost increases most significantly because of discarded wind electricity, excluding storage. In both regions the use of wind electricity would mainly avoid use of natural gas. The CO2 emissions abatement costs range from 14 (OECD Europe) to 33 (USA) $ per ton CO2 differ in both regions due to a faster wind electricity cost increase in OECD Europe.

George Marsh.

Reinforced Plastics, Vol. 51, No. 11, Dec. 2007, pp. 30-33.

Wind energy has now become a major scientific discipline with significant potential for research and education. And as legislation drives the uptake of wind, ways to improve efficiency and yield are top of many company's R&D action plans. George Marsh looks at some recent commercial developments in wind turbine technology.

W. Musial.

No. , 1 Dec 2007, pp. 141.

In 2002, the U.S. Department of Energy (DOE) established the Low Wind Speed Technology (LWST) Program to develop technology that will enable wind energy systems to generate cost-competitive electrical energy at low wind speed sites. The program goal is to reduce the cost of electricity from large wind systems in Class 4 winds to 3.6 cents/kWh for land-based systems and to 7 cents/kWh for offshore systems in a Class 6 wind regime. Much of the United States strong wind resource is located away from load centers, and limitations of the transmission system reduce the ability of land-based wind energy projects to meet the needs of these centers. Many load centers are relatively near the nations coasts, where there is a considerable wind resource; however, much of it is in areas with relatively deep water. There are also challenges associated with locating wind energy projects within view of the nations coasts. If wind energy technology can be developed to cost-effectively establish wind turbines in deeper water, where there is an abundant wind resource and the projects are not visible from shore, significant additional power could be installed. The National Renewable Energy Laboratory (NREL) issued a Request for Proposals in 2003 for a second round of contracts within the LWST program. Concept Marine Associates, Inc. (CMA) was awarded a Conceptual Design Study contract to examine the feasibility of various semi-submersible platform configurations for an offshore deep water wind turbine. This report describes the results of that subcontract, the design work involved, the design loads identified, and the overall estimated cost of energy (COE).