ZephIR - case study 4 - Risø DTU - Denmark

The Danish wind turbine industry has a 40% share of the global market and employs more than 20,000 people, making it the world leader in wind power. some 20% of their domestic electricity production comes from wind. The development of wind power in Denmark is characterised by a close collaboration between publicly financed research and industry in key areas such as research and development, certification, testing, and the preparation of standards. Risø DTU play a pivotal role in providing this R&D to denmark’s growing wind industry.

In January 2004, Risø DTU took delivery of the first ZephIR prototype, and shortly afterwards used it to perform the first lidar comparisons against their tall mast at Høvsøre. Since then, Risø have tested over a dozen ZephIR systems for the purposes of:

  • Independent correlations for customers using ZephIR as the sole source of anemometry on projects
  • Ongoing ZephIR research & development
  • Development of new products and algorithms
  • Traceable calibration for Natural Power’s ZephIR reference system


Torben Mikkelsen, Professor in the Wind Energy Division at Risø DTU, commented in 2004 that “Lidar nowadays gives rapid, reliable and accurate measurements. Notably, the technology permits wind yields to be determined at heights significantly above the furthest reach of the highest wind turbines and offers great deployment flexibility”.

The relationship between Risø DTU and Natural Power has flourished with much ongoing work involving the use of ZephIR. One such example is the recent world’s first installation of a lidar in the spinner of a wind turbine - this particular development is detailed on the next pages under ControlZephIR.

“We have been working with Natural Power ever since the very first ZephIR unit was trialled; from the start the product combined revolutionary ideas with high accuracy, and we have seen this further improved over the following years. The ZephIR team at Natural Power has always been open to developing the product, both in improving its performance and also its use in novel applications, for example the turbine mounted application and ‘Windscanner’. [Windscanner is a system combining three steerable ZephIR lidars providing 3-D wind and turbulence measurements - see www.windscanner.dk for more information].

We very much see lidar as an essential tool for the future of both the wind energy research community and the wind industry.”

- WIND ENERGY DIVISION, Risø DTU