Four models are examined which attempt to describe wind fluctuations in relation to a wind energy conversion system (WECS) that is subjected to these fluctuations observed from a fixed location within the atmospheric boundary layer. The primary purpose of this examination is to provide a basis for understanding present and future developments in gust and gust-rise models. The examination is accomplished by identifying the gust definitions used in the models and relating them to a basic definition given.
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This report summarizes work on a project performed under contract to the Alaska Power Administration (APA). The objective of this research was to make a preliminary assessment of the wind energy potential for interconnection with the Cook Inlet area electric power transmission and distribution systems, to identify the most likely candidate regions (25 to 100 square miles each) for energy potential, and to recommend a monitoring program sufficient to quantify the potential.
The spectrum of turbulence encountered by a point on a fast-rotating wind turbine blade is shown to be possibly quite different from that measured by a stationary anemometer. The physically reasonable expectations are supported quantitatively by experiments using Pacific Northwest Laboratory's vertical-plane anemometer array. The measurements indicate that the blade encounters energy densities in two regions of the turbulence spectrum much different than those seen by stationary anemometers. For typical turbine types and wind conditions, the spectral energy redistribution phenomenon may be significant only for turbine blade diameters larger than 10 m. The spectral shift should also affect gust statistics for rotting blades; the duration of gusts that are smaller than the diameter of the disk of blade rotation will decrease. Correspondingly, the rise rate will increase by a factor of about ten.
As a service element within the Federal Wind Energy Program, the Wind Characteristics Program Element (WCPE) is established to provide the appropriate wind characteristics information to those involved in: the design and evaluation of wind energy conversion systems (WECS); energy program planning; selecting sites for WECS installation; and the operation of WECS. To effectively produce the information needed in these four categories, the WCPE, for which the Pacific Northwest Laboratory (PNL) has the responsibility for management and technical assistance, has been divided into four technical program areas. During this reporting period PNL was also assigned the management responsibility for the data collection at the US Department of Energy's (DOE's) candidate sites, as well as the task of providing technical assistance to DOE evaluation and site selection panels for new candidate sites.
The computer code DARTER (DARrieus, Turbine, Elemental Reynolds number) is an aerodynamic performance/loads prediction scheme based upon the conservation of momentum principle. It is the latest evolution in a sequence which began with a model developed by Templin of NRC, Canada and progressed through the Sandia National Laboratories-developed SIMOSS (SSImple MOmentum, Single Streamtube) and DART (SARrieus Turbine) to DARTER.
The Federal Wind Energy Program (FWEP) was initiated to provide focus, direction and funds for the development of wind power. Each year a summary is prepared to provide the American public with an overview of government sponsored activities in the FWEP. This program summary describes each of the Department of Energy's (DOE) current wind energy projects initiated or renewed during FY 1979 (October 1, 1978 through September 30, 1979) and reflects their status as of April 30, 1980. The summary highlights on-going research, development and demonstration efforts and serves as a record of progress towards the program objectives. It also provides: the program's general management structure; review of last year's achievements; forecast of expected future trends; documentation of the projects conducted during FY 1979; and list of key wind energy publications.
This meeting was called as part of a multi-year planning effort. Groups involved in the production and/or dissemination of information on wind energy were invited to describe their current activities and their perceptions of the needs of the 80's in this area. Participants exchanged copies of materials they distribute regularly and discussed frequently asked questions.
Information is presented concering regional wind energy resource assessment; regional features; and state features for Idaho, Montana, Oregon, Washington, and Wyoming.
This report describes a method of determining coastal wind energy resources. Climatological data and a mesoscale numerical model are used to delineate the available wind energy along the Atlantic and Gulf coasts of the United States. It is found that the spatial distribution of this energy is dependent on the locations of the observing sites in relation to the major synoptic weather features as well as the particular orientation of the coastline with respect to the large-scale wind.
A field study was conducted at the Rocky Flats Small Wind Systems Test Center to determine if aesthetic preferences exist for particular designs of small wind machines, and to gather data on the importance of aesthetics relative to other wind system issues. Participants on public tours of the Test Center were asked to answer several general questions and to rate the visual appearance of various working parts (rotor and nacelle), towers, and complete machines. Working parts included vertical- and horizontal-axis designs (both upwind and downwind), while towers included wood, concrete and steel columns, and various truss designs. In spite of a relatively small sample size (N = 139), the results indicate definite preferences for particular designs, with downwind horizontal-axis working parts and columnar towers receiving the highest ratings.