Economic Input–Output Based Sustainability Analysis of Onshore and Offshore Wind Energy Systems

According to the U.S. Department of Energys wind energy scenario, 20% share of the U.S. energy portfolio is to come in from wind power plants by the year 2030. This research aims to quantify the direct and supply chain related indirect environmental impacts of onshore and offshore wind energy technologies in the United States. To accomplish this goal, a hybrid life cycle assessment (LCA) model is developed. On average, offshore wind turbines produce 48% less greenhouse gas emissions per kWh produced electricity than onshore wind turbines. It is also found that the more the capacity of the wind turbine, the less the environmental impact when the turbine generates per kWh electricity

A Wind Turbine and a Method for Determining the Presence and/or Thickness of an Ice Layer on a Blade Body of a Wind Turbine

A wind turbine comprising an elongated blade body, a system for detecting an ice layer on the blade body, the system comprising a light source for emitting a light beam; a light splitting optical element optically connected to the light source so as to receive the light beam emitted from the light source, the optical element adapted to split the light beam received from the light source into a reference light beam and a detecting light beam, a boundary area which is arranged at the blade body so as to be exposed to the outer surroundings of the blade body and which is optically connected to the light splitting optical element such as to receive the detecting light beam and to reflect an internal reflected part of the detecting light beam at the boundary area and to transmit a transmitting part of the detecting light beam to the outer surroundings of the blade body through the boundary area and to allow an external reflected part of the transmitting part of the detecting light beam, which has been reflected from outside of the blade body, to be re-transmitted through the boundary area, a light measuring device optically connected to the light splitting optical element so as toreceive the reference light beam, the internal reflected part of the detecting light beam and the external reflected part of the detecting light beam, wherein the light measuring device is configured to analyze the received light and to determine the presence and/or thickness of an ice layer on the blade body dependent on the analysis

Measuring Loads on Wind Turbine Blades

A sensor system for measuring aerodynamic loads acting on a wind turbine rotor blade is disclosed. The measured aerodynamic loads can be converted to an angle of attack of the resulting wind which flows past the moving rotor blade. The sensor is realised as a trailing edge flap which is elastically moveable relative the main part of the wind turbine blade. By measuring motion of the trailing edge flap or corresponding motions of components of the sensor system, the aerodynamic forces acting on the blade can be determined. Due to the relative small dimensions of the sensor flap and the relative small displacements of the flap, the sensor system only affects the aerodynamic properties insignificantly