A two-year trial to collect wind speed data at sea, using innovative laser-based measurement devices mounted on floating buoys, has concluded. RWE Innogy, together with the Carbon Trust's
Offshore Wind Accelerator (OWA) programme, tested the Light Detection and Ranging units (LIDAR) technology at what is soon to become the world’s second largest offshore wind farm: a 576MW, 160 turbine
Gwynt y Môr offshore wind farm located in the Liverpool Bay, off the North Wales coast.
The trial, which started in September 2012, assessed the effectiveness of the LIDAR prototypes in recording and analysing local wind conditions. As part of the trial, two LIDARs were mounted on buoys and installed close to the existing meteorological mast of Gwynt y Môr offshore wind farm. Both units collected wind data, which was then compared with information from the met mast, with good results.
The two models trialled, include one manufactured by the Belgian company "FLiDAR", and the other by the UK support services company Babcock International Group. The models differed in terms of design; the prototype developed by FLiDAR having a motion compensation with a Leosphere LIDAR system, and the Babcock prototype being characterised by its low motion buoy design with a Natural Power ZephIR LIDAR system.1
Both prototypes were towed by ship to the chosen measuring site where they were anchored to the seabed, with electricity supplied by photovoltaic panels and micro-wind turbines installed on to the buoys. Like conventional met masts, the buoys were proven to supply weather data on wind velocities and wind direction, up to a height of 200 metres.
An independent review by energy consultants DNV GL highlighted that the new technology is capable of providing accurate wind speed measurements when the measurement buoys are exposed to waves, currents and tides.
“The trials are significant for both individual projects and also for the offshore renewables industry as a whole," said Michael Rea, Carbon Trust chief operating officer. “The
Offshore Wind Accelerator programme, developed and managed by the Carbon Trust, has the aim of reducing the cost of offshore wind power by 10 per cent in time for Round 3. The results of this research highlight how the development of innovative technology can play a very real and critical part in helping us reach this aim.”
What this trial has shown, said Paul Cowling, director of Offshore Wind at
RWE Innogy, is the "importance of research and development projects in helping the industry continue to find effective and innovative methods of utilising technology to reduce costs and improve efficiency.”
Working on behalf of the project, systems engineering specialist Frazer-Nash Consultancy undertook the data analysis. “The analysis demonstrated not just the ability of the systems to measure wind speeds, but also how that ability is affected by sea state and atmospheric conditions," said Neil Adams, Frazer-Nash Consultancy’s project leader. “This will help developers judge how the systems could perform at their sites and will help add value to their operations.”
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- The results highlight that the LIDAR technology is progressing well towards being effectively deployed to collect meteorological and oceanographic (metocean) data. The benefits of the new technology include it costing a fraction of the cost of a fixed met mast – currently the traditional method of collecting such data at offshore wind farms. The two-year trial also indicated that floating LIDARs can be quicker to deploy and cheaper to install than traditional met masts. It is also possible to move the floating LIDAR systems around site, giving developers more accurate data on the actual wind resource available.