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Wind energy in the United States and materials required for the land-based wind turbine industry from 2010 through 2030

Improved methodology for design of low wind speed specific wind turbine blades

Apart form the hydro-electricity, the wind power has emerged as the most promising renewable resource for its industrial technological base, and the experience and reliability attained in the last 20 years of operation of small and large systems worldwide. In spite of the phenomenal growth and development in the last decades, the wind turbines' industry keeps moving forward in order to increase the efficiency and controllability of the wind turbines and to easy the integration to the power grid. This paper presents an overview on the changes the power systems are going through and discusses important aspects arising from the large scale penetration of wind energy into electrical power grid, as the challenges related to the transmission and distribution infra-structure, issues related to the balance, reserve and prediction of the wind power as well as the wind turbines fault ride-through capability. The wind power has caused many transformations in the power systems' planning and operation strategies, grid codes reviews and in the energy market.

A Comprehensive Overview on Wind Power Integration to the Power Grid

For the next generation of larger off-shore wind turbines, it has been suggested to use feedback to actively control the blade vibrations, thus decreasing fatigue damage and increasing the life of the machine. Because of both practical engineering difficulties and fundamental control theoretic limitations, it seems that individual pitch actuation may not be well suited for this type of control, prompting researchers to investigate other forms, such as tip actuation and the ‘smart blade’ concept. Most research in this area has been on the design of cheap, reliable and effective actuators and sensors, which are necessary for economic viability of the concept. We will argue that the design of a robust feedback controller is just as critical to the success of the smart blade concept, but has been so far overlooked because of the complexities of modeling and computation involved therein.

In this paper, we take the first step in demonstrating how to build blade models with a distributed bounded uncertainty structure, in a framework appropriate for robust control analysis and design. We then discuss recent progress in distributed computationally efficient robust control techniques, scalable for very fine discretizations, and show that for coarse discretizations, even centralized techniques can be employed to design high-performance feedback controllers for a smart blade system, with guaranteed closed loop stability and performance for a variety of operating conditions and model mismatches. Copyright © 2009 John Wiley & Sons, Ltd.

Robust and distributed control of a smart blade

The aim of this paper is to do a literature review of the design process of offshore wind turbines (OWTs). The paper uses an approach in which the design process of an OWT is divided into three steps. Firstly, different requirements which should be satisfied by an OWT are classified. Secondly, different design solutions are reviewed and some design choices such as number of blades and tip speed ratio is explained. Finally the analysis tools to evaluate the solutions are studied and the up-scaling rule which is a way to get some general insight in an OWT characteristic is explained.

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Review of design concepts, methods and considerations of offshore wind turbines

This paper describes the growth, advances, and challenges faced by the wind energy industry in 2006.

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Advanced Wind Technology: New Challenges for a New Century

The United States Department of Energy (DOE) Wind Energy Research Program has begun a new effort to develop wind technology that will allow wind systems to compete in regions of low wind speed. The sites targeted by this effort have annual average wind speeds of 5.8 m/s measured at a 10-meter height. Such sites are abundant in the United States and would increase the land area available for economic development twentyfold. DOE has initiated a three-element approach through a competitive request for proposals. The three elements in the RFP include concept design, component development, and system development. This work will build on previous activities under the WindPACT Program and the Next Generation Turbine Program. The new program is targeting a levelized cost of energy of 3/kWh at low wind speed sites by 2010 and supports the U.S. wind industry's goal of reaching an installed domestic wind capacity of 100 GW by 2020.

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A. Laxson

Papers

Advanced Wind Technology: New Challenges for a New Century

Low Wind Speed Technology Development in the U.S. Department of Energy Wind Energy Research Program: Preprint