Wind lidar as alternative to met masts

The Dogger Bank projects being developed by the Forewind consortium will have a capacity of 4.8 GW and, as part of their assessment process, two meteorological mast platforms were installed during 2013. In November 2014, a ZephIR 300 wind lidar was installed on the east meteorological mast platform by sister company SeaRoc Group to provide continuous data above the existing mast height, while the mast underwent maintenance works.

The lidar collected wind speed information for four months to April 2015, and when the meteorological mast was reinstalled in May 2015 it continued wind speed measurement at the mast's base. Results confirm that the lidar was available for 100% of the time and correlations to the met mast were found to be excellent and at least as good as variations between individual cup anemometers.

Ian Locker, MD at ZephIR Lidar said: "The ZephIR Lidar poses clear long-term financial and health and safety advantages over traditional anemometry as it requires fewer personnel to carry out maintenance tasks and vessel time offshore is significantly reduced. The [lidar installation] allowed for the possibility that there would be no gap in wind data during the mast maintenance period and has essentially extended the height of the mast significantly. It produced high availability and high accuracy of data, and was perfectly reliable, confirming that it could be used alone for wind data collection at a fraction of the cost."

The ZephIR Lidar has the ability to record data from a height of 300m down to just 10m. SeaRoc has now installed three such lidars including two for Forewind, this one on the Dogger Bank Met Mast East and an earlier installation on the Cavendish platform in 2011.

(Originally published in MPS January 2016)