- Category: Articles
Can SiteWind lower uncertainty and costs?
Conventional micrositing models such as WAsP (Wind Atlas Analysis and Application Program) are equilibrium models that create a wind map and climatology of a region using data from a single reference mast. The models typically assume a constant, homogeneous, neutrally stratified, externally determined wind flow; the terrain acts as a perturbation on this flow. In contrast, SiteWind, a new micrositing tool introduced by AWS Truewind, resolves the dynamic forces within the region affecting the flow caused by temperature gradients, non-neutral stability and other factors. In this article the authors present the results of case studies and discuss their implications for uncertainty analysis. They also show how the demonstrated accuracy improvements can translate into lower uncertainty of energy output estimates.
By Rebecca Reed, Michael Brower and Jason Kreiselman, AWS Truewind, USA
- Category: Articles
A Clear Picture?
In the early 1990s a number of test wind turbines were installed in Denmark and Sweden. The turbines were small compared to the current size and output of turbines, and the waters in which they were installed were relatively quiet. The installation could easily be managed using existing floating cranes and barges. Now that large-scale wind power plants are being installed offshore in more exposed areas such as the North and Irish Seas, more ‘rugged’ methods are needed in order to install large quantities of high megawatt turbines in a short season. In this article, Kurt Thomsen from A2SEA A/S gives his views on this matter.
In the early 1990s a number of test wind turbines were installed in Denmark and Sweden. The turbines were small compared to the current size and output of turbines, and the waters in which they were installed were relatively quiet. The installation could easily be managed using existing floating cranes and barges. Now that large-scale wind power plants are being installed offshore in more exposed areas such as the North and Irish Seas, more ‘rugged’ methods are needed in order to install large quantities of high megawatt turbines in a short season. In this article, Kurt Thomsen from A2SEA A/S gives his views on this matter.
By Kurt Thomsen, Business Development Manager, A2SEA A/S, Denmark
- Category: Articles
Te Apiti Wind Farm Proves Wind Energy can be Mainstream Generation
Using an abundant wind resource, New Zealand’s largest electricity generating company, Meridian Energy, has constructed its first wind farm in the North Island and plans to repeat the experience. The wind farm, at Te Apiti, is expected to be completed and fully commissioned by the end of 2004, demonstrating that the wind generation industry has begun to mature in New Zealand.
By Adam Muldoon, NZ Wind Development Manager, Meridian Energy, New Zealand
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Using an abundant wind resource, New Zealand’s largest electricity generating company, Meridian Energy, has constructed its first wind farm in the North Island and plans to repeat the experience. The wind farm, at Te Apiti, is expected to be completed and fully commissioned by the end of 2004, demonstrating that the wind generation industry has begun to mature in New Zealand.
By Adam Muldoon, NZ Wind Development Manager, Meridian Energy, New Zealand
- Category: Articles
Laser Radar (lidar) – a Revolutionary Method of Wind Resource Measurement
Optimal siting of wind farms and positioning of turbines requires a thorough understanding of local wind flow and turbulence conditions. But these can be difficult to quantify and time-averaged measurements at a few selected locations may not be fully representative. Complex sites present particular difficulties, as cliffs, buildings and trees all serve to modify the wind flow. With turbine hub heights now reaching over 100m, conventional met-masts of 50m or so cannot always provide the confidence needed to predict future wind farm productivity. A new, ground-based, remote wind lidar (light detection and ranging) system has been developed to overcome the cost and deployability issues associated with conventional laser radar systems. It has been shown to operate reliably in remote locations, and in independent tests has demonstrated accuracy comparable to the best calibrated cup anemometers in use today.
By David A. Smith, Qinetiq, UK
- Category: Articles
Optimisation of Foundation Schemes in Terms of Overall Economic Viability
Over 15% of the cost of an offshore wind turbine is usually attributable to the foundations. Foundation installation and erection of the turbine constitutes one of the greatest areas of risk for an offshore development, because of the problems posed by working in an often difficult marine environment. Developing alternative foundation systems and addressing installation techniques that are less weather sensitive will have a direct and significant impact on the economic viability of offshore wind farm schemes. Results of studies for several offshore wind sites are presented in this article to demonstrate the savings that can be made by innovative thinking in terms of foundation design and construction. Relative costs of foundation systems are compared for differing seabed conditions, together with an assessment of the associated risks in terms of certainty of out-turn costs and schedule.
By Rachel Nicholls, Associate, Arup, USA
- Category: Articles
Development of the Sheringham Shoal wind farm
Scira Offshore Energy (Scira) is developing a 315MW offshore wind farm 20km north of the Norfolk coast in UK waters. Scira is a special-purpose vehicle of Ecoventures from the Netherlands and SLP Energy from the UK. Ecofys BV is technical consultant to Scira, providing technical project management and specialist services. In this article the preparations for this large wind farm are described along the lines of the technical, organisational, economic and environmental requirements.
By Quirin Sluijs, Manager Wind Energy, and Bernard van Hemert, Senior Consultant, Ecofys BV, The Netherlands
- Category: Articles
The Design of a Cost-Effective Turnkey Solution
Before an offshore wind farm site is installed, there must be a geographical survey, wind analysis and environmental impact study for the area in consideration. To conduct these surveys and studies it is beneficial to have a site monitoring. In this article the authors describe the design considerations for such a system.
Before an offshore wind farm site is installed, there must be a geographical survey, wind analysis and environmental impact study for the area in consideration. To conduct these surveys and studies it is beneficial to have a site monitoring. In this article the authors describe the design considerations for such a system.
By Hans-Jorgen Hansen and Steven Thumbeck, MacArtney A/S, Denmark
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