Met monitoring systems, including LIDAR, are commonly used on-shore by the renewable energy industry and by military and aviation organisations.
However, their deployment offshore has so far been limited by the high costs of constructing fixed platforms for meteorological mast installation and the technical challenges of using a floating platform which is cheaper and faster to deploy yet makes gathering accurate, high quality data more complex, said Babcock.
LIDAR systems measure wind speed and direction by comparing the light from a laser beam, reflected by microscopic dust particles in the atmosphere, to a reference light source.
By measuring the change in the reflected light’s frequency, caused by the Doppler shift, the speed and direction of the dust particles and corresponding wind velocity and direction, can be determined.
The motion a floating offshore platform is subjected to, however, affects the quality of the data collected, requiring either a physical motion compensation system, or post-processing of data using complex algorithms, said the company.
But now, Babcock said it had produced a floating platform with the low motion characteristics necessary to allow wind measurements to be obtained with the required levels of accuracy at minimal cost without the need for compensation systems or complex data processing algorithms.
Babcock’s floating LIDAR system has been designed to provide the stability to deploy measurement and monitoring sensors on a floating platform to collect reliable data to support offshore wind farm planning, development and operation, without the need for compensation
In addition to the platform design, Babcock said it had developed an integrated power system - supplied by photovoltaic panels and micro wind turbines installed on the buoy - and communication system to facilitate remote, autonomous operation of the platform.
A six month trial of the Babcock floating LIDAR system is now set to take place, hosted by RWE Innogy at a location adjacent to the fixed met mast at RWE’s Gwynt y Môr off the north Wales coast in the Irish Sea, said the company.
The trial, which will allow a detailed independent assessment of the system (comparing the data with information from the met mast), is part of the Offshore Wind Accelerator (OWA) programme, promoted and co-ordinated by the Carbon Trust with the aim of reducing the cost of offshore wind power.
“The floating LIDAR system is one of a new breed of technological improvements for the offshore wind sector, for the recording and analysing of local wind conditions,” said Babcock programme manager Liam Forbe.
“By proving this system Babcock will be able to help drive down costs both in construction and throughout the life of the wind farm, as well as enabling the development of the next generation of deep water sites,” he said.