Wind resource assessment systems: Review of new solutions based on laser technology

The available wind speed potential strongly depends on the existing wind profiles at different locations. In this way, the exploitation of this resource can be determined by the wind turbine power curve, relating both wind speed at the rotor hub and electric power from the wind turbine. According to the current international Standard for power performance, the wind speed at hub height is the main input parameter for the characterization of the power curve, being considered the air density as a secondary factor. Under this framework, the wind speed is considered as constant over the whole turbine swept rotor area. This assumption can achieve high level of accuracy for small wind turbines. However, current wind turbines are characterized by a large rotor diameter, being exposed to remarkable variations in wind speed with height. Moreover, this Standard will be modified in a short-term, with the aim of taking into account several wind measurements within the swept rotor area. This paper reviews recent solutions to measure wind speed and direction based on remote sensing systems: SODAR and LIDAR technology. These systems are able to collect vertical wind profiles over a wide range of heights, providing a significant advantage in comparison with conventional approaches.