Oldbaum is very proud to be working with nacelle LiDARs – a tool particularly useful for offshore operations.
Current practice for in-situ assessment of a wind turbine is based on measurements taken by anemometers mounted after the rotor blades. Problematically though, these measurements are affected by complex aerodynamic effects caused by the motion of the turbine rotor blade and shape of the nacelle. Correction functions exist for this but introduce a large amount of uncertainty and are dependent on test site conditions.
A LiDAR mounted on the nacelle of a turbine, by contrast, is able to measure the wind as it comes on to the rotor blades with measurements unaffected by the turbine. The novel data which is collected this way can then be used to investigate and maximise turbine yield, and also may have a significant impact on Operations & Maintenance by decreasing asymmetric loading.
Nacelle LiDARs have been widely used in a number of onshore and offshore applications, which include:
- Upstream wind speed with the accuracy of a 1st class anemometer
- Power performance assessments equivalent to IEC 61400-12-1
- Yaw misalignment studies
- Calibration of nacelle mounted anemometer and wind vane to upstream values
- Examination of terrain effects and the turbine induction zone
- Site calibration in complex terrain
- Turbulence and wake effect studies
Normally, more than one of the above measurement goals can be achieved simultaneously which means that more value can be extracted from the data collected during a single measurement campaign. A typical measurement campaign therefore can assess how well a turbine is currently performing, gather the data required to optimize performance, inform turbine control strategies, and verify the effectiveness of any changes made. The LiDAR’s position on the nacelle allows it to gather data for all turbine orientations which allows for quickly assessing the turbines performance for various wind sectors and wind conditions.
Turbine optimization process using nacelle mounted LiDAR
The Wind IRIS from Avent LiDAR Technologyis a two-beam pulsed LiDAR designed for the use on wind turbine nacelles. It has been used extensively within the wind industry and deployed on over 30 different turbine models worldwide. The Wind IRIS uses two pulsed beams to measure horizontal wind speed and wind direction with a range of 40m to 400m. The system is capable of delivering high frequency data for turbine control or turbulence evaluation, or lower frequency returns for longer range work.
Typically, the installation of a Wind IRIS takes just half a day, and Oldbaum’s team of GWO trained experts will ensure that installation of the LiDAR has a minimum effect on the access to the turbine nacelle as well as on the turbine’s anemometry. As the LiDAR’s measurement area moves with the turbine it is also allows for collecting more comprehensive data more quickly than traditional met mast anemometry as more measurement sectors are available. The Wind IRIS is a flexible solution that can be rapidly deployed across multiple assets.
Oldbaum Services are members of Avent’s Wind Experts programme and have experience of deploying the Wind IRIS on multiple turbine types onshore and offshore. With our expert help clients can expect a complete data service including installation, performance monitoring, and access to data through our secure data portal. Oldbaum can also offer a data analysis service to ensure that our clients can maximise the lifetime and yield of their turbines.