By Kari Williamson

ZephIR 300 – a lidar system for measuring wind speed and characteristics from ground level up to 200 metres - was deployed in LM Windpower’s wind tunnel in Denmark and measured wind speeds from 5 m/s to 75 m/s with an averaged difference of just 0.4% for a sustained period of time and across all measured speeds, Natural Power says.

The test results feed in to the DNATF project Integration of Wind LIDAR’s in Wind Turbines for Improved Productivity and Control, which is carried out with Denmark’s National Laboratory for Sustainable Energy, Risø DTU, wind turbine blade manufacturer LM Wind Power and optical and laser solutions provider, NKT Photonics.

The tests also demonstrate the performance of a sister product of ZephIR 300 developed by Natural Power called ControlZephIR which has a different system software and mechanical housing to allow the unit to be either spinner or nacelle mounted.

Ian Locker, ZephIR MD at Natural Power, says: “We are very proud to be supporting Risø DTU, LM Wind Power and NKT Photonics to demonstrate how ZephIR can be used to improve wind turbine control. These independent results show that whether ZephIR is looking forward for turbine control, or looking up for resource measurement, the system is highly accurate and can actually match the performance of a calibrated wind tunnel.

“By the end of the year we will have accumulated over 2.5 million operational hours on ZephIR systems globally, and we will also be launching a full commercial ControlZephIR system which has already undergone extensive testing across prototype installations in 2003, 2009 and 2010 and is currently being mass produced in the UK prior to roll-out.

The LM Wind Power wind tunnel is a closed circuit wind tunnel with a closed test section with flow driven by a 1 MW fan that can reach a flow speed of up 105 m/s.