GROUND-BASED REMOTE SENSING SYSTEMS - Wind Resource Assessment: A Practical Guide to Developing a Wind Project - page 103

8
GROUND-BASED REMOTE
SENSING SYSTEMS
As wind turbines become larger and the size and complexity of wind projects increases,
there is a need for wind resource data from greater heights and in more locations
across a project area. Ground-based remote sensing, which includes sodar and lidar,
can help meet this need. Sodar and lidar measure the wind resource to heights of
150 m or more above ground, well beyond the reach of tilt-up towers. In settings
where fixed masts are prohibitively expensive or not technically feasible, sodar and
lidar may be the sole source of wind measurements. More frequently, they are used
in conjunction with fixed masts, which remain the standard for resource assessment.
Although the practice of relying entirely on remotely sensed data remains rare, it is
likely to become more common as the cost of the technology decreases, its accuracy
and reliability continue to improve, and experience with it grows.
The main advantage of remote sensing is the ability to measure wind charac-
teristics above the heights of most wind monitoring towers and across the rotor
plane of modern, large wind turbines. This can reduce the uncertainty in wind shear
and energy production estimates. Information on turbulence, vertical motions, and
directional shear (veer)—all of which can affect turbine performance—can also be
obtained.