Industry adoption of scanning lidar technology is growing. Recently, UL’s offshore team completed a successful year-long scanning lidar campaign designed to assess the local wind resource in support of offshore wind farm development in the German North Sea. For this campaign two scanning lidars were deployed and operated from fixed platforms, namely, an offshore sub-station and a wind turbine. The success of this program was not just dependent on the hardware. It required optimized planning, robust deployment of the system, experience in monitoring the operation, and definitively advanced data analysis know how.
How lidar is used in offshore wind development
Scanning wind lidar systems offer the possibility to measure the wind remotely and have become one of the preferred solutions to measure offshore wind. The flexibility and its compact size make scanning lidar easy to deploy on fixed offshore platforms, on nacelles and transition pieces of offshore wind turbines at any stage of a wind farm project, from prospecting to operation.
To determine the horizontal wind field in an offshore location a scanning lidar is able to scan the wind in different directions at a fixed elevation. The wind speed and direction are calculated for confined areas in the scanned domain. Eventually, wind profiles are constructed by measuring at different elevations, ranging from sea level to the top blade tip height or further. Scanning lidar is ideal for offshore wind measurement because it fulfills customizable scan patterns. The patterns can have a vertical or horizontal variation, which provide information on wind speeds over a wider area in height and direction. From those scan patterns a virtual mast can be constructed at several locations of interest and at a distance up to several kilometers from the device. Virtual met masts are only one example how to benefit from the latest lidar technology. Customized lidar scans can also give insight into local wind flow.
UL’s scanning lidar program has proven to be a robust tool for wind resource assessment. It is also a great application for measuring inflow conditions at offshore wind farms. Here of some of the benefits to deploying scanning lidar technology.
- A scanning lidar is able to deliver local information of the wind resource at defined virtual met masts in a surrounding area of about 2 km.
- Scanning lidar is able to analyze the spatial distribution of wind speeds in complex flow situations like near-coastal offshore sites.
- Energy assessments based on either of the above measurement types or in combination with traditional wind measurement sources such as met masts.
- A virtual met mast of a scanning lidar is used as input for power curve evaluations.
- Details of the wake field can be revealed by scanning the wake at different positions and distances.
- We add value to your campaign by checking the performance of the scanning lidar against our IEC conforming met mast before or after the measurement campaign.
The use of scanning lidar for offshore wind measurement is growing
In addition to the project in the German North Sea, UL is currently operating several offshore scanning lidar campaigns. These campaigns include offshore resource assessments for the Federal Maritime and Hydrographic Agency, as well as blockage and wake measurements for the research projects X-Wakes and FINO1.
Figure 1: Top view of line-of-sight wind speed for a full scan over approximately one minute. Measurement nearby the FINO1 offshore platform for a maximum range of 1.8 km.
Figure 2: Bird view of line-of-sight wind speed for a full scan over approximately one minute. Measurement nearby the FINO1 offshore platform for a maximum range of 1.8 km.
The deployment of scanning lidar is ideal in offshore environments, but the success of the campaign is dependent on the optimized planning, robust deployment and dismantling of the system, experience monitoring the operation, advanced data analysis tools and comprehensive reporting. UL has worked extensively in offshore wind resource and energy assessment. If you are interested to learn more about UL’s offshore scanning lidar program reach out to our offshore wind staff.
Operations Manager, Renewables
Engineering Lead, Renewables