摘要:

The global wind-energy resource is very large and widely distributed; and, within Europe, wind energy has the potential to provide an energy output equal to about three times the present electricity consumption. Although the wind is not very reliable as a source of power from day to day, it is a reliable source of energy year by year, and the main role for future wind-energy systems will be operating in parallel with electricity grid systems or, in remote locations, in parallel with diesel engines, so saving fuel. Systems integration studies indicate that existing utility grid systems could accept a contribution of about 20% from wind turbines, although, with changes to the future plant mix, the potential contribution is substantially greater: and similar percentage fuel savings are possible in remote locations with wind/diesel systems. Recent progress in the development of wind turbines is reviewed and the cost data now becoming available indicates that medium-sized machines, i.e. ≃ 20–40 m diameter and with power ratings in the range 50–500 kW, offer the most attractive economics for land-based applications in the near future, giving energy costs in the range 2.8–5.6 p/kWh, for a typical site where the annual average wind speed is 5.5 m/s (measured at the normal 10 m height); in windier locations energy costs will be lower. Corresponding capital costs for installed wind turbines are in the range £750–1500/kW (with average outputs equal to about 30% of the rated). The UK, in common with some other countries, has a large offshore wind-energy potential, but, to be economically competitive, offshore systems will need to use multimegawatt wind turbines with diameters of 100 m and larger. Prototype machines in this size range already exist, but considerable further development is needed before the construction of large offshore wind turbine arrays can commence, although this is a realistic prospect for the 1990s. The economics of wind-energy conversion systems are already encouraging, and commercial applications already in evidence, most notably in the USA and Denmark where more than 2000 wind turbines with a total installed capacity in excess of 150 MW have been installed in the past two years. However, further operational experience is required to demonstrate that reliable operation can be sustained over periods of many years. As this experience is accumulated, and as the cost benefits associated with quantity production are achieved, the market for wind turbines can be expected to expand rapidly.

DOI:10.1049/ip-a-1.1983.0078

出版商:IEE    

年代:1983

数据来源: IET

摘要:

Estimates of winds at heights of around 100 m are required for the siting of large wind turbines. Because of uncertainties often attached to the normal method of extrapolating from data at 10 m, a method of extrapolating from upper-air data has been developed. The predictions of this method are compared with measurements at several stations on land and one offshore.

DOI:10.1049/ip-a-1.1983.0079

出版商:IEE    

年代:1983

数据来源: IET

摘要:

Three principal aspects of the dynamics of wind-turbine behaviour are discussed: forced response to deterministic loads, forced response to stochastic loads and stability. In each case, an introduction to the physics of the problem is presented and a means of analysis is described. A simple analytical model is derived to help illustrate some of the analytical techniques commonly employed.

DOI:10.1049/ip-a-1.1983.0080

出版商:IEE    

年代:1983

数据来源: IET

摘要:

Boeing involvement with wind energy began in 1977 with the award of the US Department of Energy (DOE) sponsored MOD-2 programme to design, fabricate and install the first multimegawatt rated wind turbines developed for commerical operation. Five 2.5 MW MOD-2 turbines have been installed: three at Goldendale, Washington, one at Medicine Bow, Wyoming and the first unit sold to a major utility located in Solano County, California. These five units have operated on-line for over 4200 hours and generated over five-million kilowatt-hours of energy. The DOE MOD-5B programme to design, fabricate and install a third generation multimegawatt machine was awarded to Boeing in 1980. The MOD-5B incorporates the operational and test experience obtained with the MOD-2 test wind turbines as well as a great many performance improvements. These items, coupled with a continuing effort of design simplification, combine to give a wind turbine which will be highly reliable and meet the economic objectives of electric utility customers. This paper presents a summary of experiences to date with the MOD-2 machines, and the current status of the MOD-5B design.

DOI:10.1049/ip-a-1.1983.0081

出版商:IEE    

年代:1983

数据来源: IET

摘要:

The General Electric Company Advanced Energy Programs Department is designing, under DOE/NASA sponsorship through Contract DEN 3-153, the MOD-5A wind-turbine system which must generate electricity for less than 3.75 ¢/kWh (1980 dollars). During the conceptual and preliminary design phases, the basic features were established as a result of trade-off and optimisation studies driven by minimising the system cost of energy. During the past year, the programme has been in the final design phase, and a reassessment to minimise risk has received strong emphasis in the design process. The programme has progressed to the point that an agreement of sale has been reached for the first unit.

DOI:10.1049/ip-a-1.1983.0082

出版商:IEE    

年代:1983

数据来源: IET

摘要:

The installation of two full-scale prototypes represents the major part of the Swedish wind-energy programme. The 2MW WTS 75 at Näsudden is one of these installations. In the paper, the time schedule and presents status of this project is reported. WTS 75 is a two-bladed horizontal-axis upward machine with full-span pitchable blades. It is built for fully automatic and unattended operation and is designed for 30 years service life. A summary of essential performance characteristics and main data are given. The design concept and build up of different subsystems are described. Shop assembly and testing of components as well as testing of the complete assembled nacelle are described. Furthermore, methods applied for construction of tower foundation are shown. Lifting and installation of nacelle and turbine to the tower top are described. Finally a summary is given of activities during first operation, acceptance tests and full-scale evaluation.

DOI:10.1049/ip-a-1.1983.0083

出版商:IEE    

年代:1983

数据来源: IET

摘要:

A 300 kW, 22 m diameter wind turbine has been designed by James Howden and Company, and erected (July 1983) on the site of the North of Scotland Hydro-Electric Board at Burgar Hill in Orkney. The machine and its design concepts are described.

DOI:10.1049/ip-a-1.1983.0084

出版商:IEE    

年代:1983

数据来源: IET

摘要:

Recent Canadian progress in the development of the curved-blade Darrieus vertical-axis wind turbine (VAWT) is described. Co-operation between government, industry and power utilities in the conduct of field trials, over several years, has demonstrated inproved performance and reliability of grid-coupled turbines of this type. The rated power of the VAWTs currently under test ranges from 30kW, in a wind/diesel powerplant, to 230 kW, in an installation on an island in the Gulf of St. Lawrence. Progress has also been made in understaning the basic aerodynamic behaviour of the VAWT and theoretical methods for performance and load prediction have correspondingly improved. A brief description is given of ‘Project EOLE’, a co-operative project between the federal government and the utility Hydro-Quebec to develop and test, during the next two to three years, a 4 MW VAWT prototype, which will be coupled to the power grid at a location on the south shore of the St. Lawrence River.

DOI:10.1049/ip-a-1.1983.0085

出版商:IEE    

年代:1983

数据来源: IET

摘要:

A field measurement programme was carried out at the cluster of three MOD-2 wind turbines located at Goodnoe Hills, Washington, to determine the rate of decay of wake velocity deficit with down-wind distance in various meteorological conditions. Measurements were taken at hub height (60 m). Wake wind speeds were measured using a radiosonde suspended from a tethered balloon, its position being determined from a grid of ground stakes. Instantaneous readings were recorded by each system every two seconds and averaged over ten-minute periods. As a control experiment, the sonde was also operated next to the meteorological tower to calibrate the instrumentation. Measurements were also made down wind with the turbine off to determine the magnitude of terrain-induced variations in wind speed. Downstream distances of 274.3, 457.2, 640.1 and 823.0 m from the turbine, corresponding to 3, 5, 7 and 9 rotor diametersD, were investigated. There was considerable scatter in the observed 10min average downstream/free-stream velocity ratios. Turbine-on velocity ratios showed even greater scatter, suggesting that only some measurements were, in fact, representative of wake centre-line velocities, and that others were made off centre line due to wake meander or wind shift. Isolation of the high wind speed (13.4 to 20.1 m/s) velocity ratios, however, revealed velocity deficits of up to about 50% at 3Dand 5% at 5Ddownstream. Measurements at greater downstream distances showed no wake deficit within the limits of resolution of the experiment, indicating that the wake had recovered to free-stream conditions.

DOI:10.1049/ip-a-1.1983.0086

出版商:IEE    

年代:1983

数据来源: IET

摘要:

The feasibility of constructing large arrays of wind turbines (100–1000 machines) has now been firmly established. The energy losses are predictable, and can be kept below 20–25% with suitable choice of spacing. The energy yields of clusters have been calculated so as to quantify the UK offshore windpower resource, and estimates have also been made as an input to assessments of the problems and costs of both onshore and offshore siting. Plans for construction of arrays have now been announced by a number of electricity supply authorities, including the CEGB. Provision of performance prediction data for these arrays, particularly the smaller ones, will necessitate development of existing techniques to take into account the operating characteristics of particular machines. The procedures are illustrated using the specific example of the Nibe cluster, where wake measurements are currently being made, and the annual energy loss for this cluster is estimated at 3%. It is concluded that spacings can be reduced with fewer machines: from the 10–12 rotor diameters applicable in large arrays down to five diameters, as at Nibe, with, say, two-four machines. The requirements for further analytical and experimental studies are discussed, with particular reference to the current UK programme, but also, where appropriate, to studies being carried out elsewhere. Data on the wakes and interactions of large machines are needed, especially for comparison with estimates derived from the predictive techniques. An assessment of the limited data currently available confirms, qualitatively, the value of corroborative studies at model scale, but points to the need for a more detailed understanding of the mechanisms of wake generation and decay.

DOI:10.1049/ip-a-1.1983.0087

出版商:IEE    

年代:1983

数据来源: IET