Wind Measurement Buoy Helps Reduce Offshore Wind Costs

Offshore wind developers will now be able to gather greater data from potential wind sites thanks to a new offshore wind measurement buoy.

Researchers from the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) in Germany have developed a new wind measurement buoy packed “with sophisticated, precise measurement technology” which is able to provide offshore wind developers with the necessary data they need to determine the profitability of a potential offshore wind project.

“Constant high wind speeds at sea can offset the huge investment costs for building the farms and connecting them to the grid,” said Claudia Rudolph, scientist at the Fraunhofer Institute for Wind Energy and Energy System Technology in Bremerhaven. “The profitability of wind farms comes from the difference between feed-in compensation and the costs for construction and maintenance.”

The new measurement buoy uses a LiDAR (Light Detection and Ranging) measuring device built into the buoy that measures wind speeds at heights between 40 and 200 meters — perfect for determining the suitability of a location for an offshore wind farm.

“LiDAR systems send pulsed laser beams into the atmosphere, which reflect off of aerosol particles in the air,” explains Rudolph. “From the frequency shift of the backscattered signal, the wind speed and direction are calculated at the corresponding measurement heights.”

With more precise and comprehensive data, wind energy developers can get a better picture of a locale’s suitability to provide continual wind energy. And though LiDAR technology was originally thought to be too imprecise for offshore applications, researchers from IWES built a corrective algorithm that erases the buoy’s own movement from the data it provides. The new measurement buoy has provided data with a 99.7% correlation with traditional met mast data.

“Out in deep water, the LiDAR buoy is a genuine alternative to wind met masts, which measure wind speeds only at a height of 100 meters,” says Rudolph.