Life cycle assessment of the Seagen marine current turbine

The world's first commercial‐scale grid‐connected tidal current energy installation will feature the Seagen marine current turbine developed by Marine Current Turbines Ltd. With potential for the manufacture of significant numbers of such devices there is a need to assess their environmental impact and, in particular, their life cycle energy and carbon dioxide (CO2) performance. This paper presents an analysis of the life cycle energy use and CO2 emissions associated with the first generation of Seagen turbines. The detailed assessment covers the embodied energy and CO2 in the materials and manufacturing of components, device installation, and operation along with those for decommissioning. With relatively conservative assumptions, and despite the early stage of development, the study shows that at 214 kJ/kWh and 15 g CO2/kWh, the respective energy and carbon intensities are comparable with large wind turbines and very low relative to the 400 to 1000 g CO2/kWh typical of fossil‐fuelled generation. The energy payback period is approximately 14 months and the CO2 payback is around 8 months. The embodied energy and carbon show limited sensitivity to assumptions with environmental performance remains excellent even under the most adverse scenarios considered. Materials use is identified as the primary contributors to embodied energy and carbon with shipping also significant. Improvements in the environmental impact of the Seagen can be achieved primarily by increased structural efficiency and the use of alternative installation methods to increase recovery of steel at decommissioning

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