OFFSHORE RESOURCE ASSESSMENT - Wind Resource Assessment: A Practical Guide to Developing a Wind Project - page 203

Figure 14-7. Installation of the FINO 1 offshore research platform using a jack-up barge (left)
and a crane barge (right). Source: FINO 1 research platform, Copyright Bilfinger Berger Civil,
Germany.
sensing advance, offshore developers are increasingly turning to these devices (pri-
marily lidar) as stand-alone wind monitoring tools. This trend is reinforced by the
growing use of remote sensing for such demanding applications as power curve veri-
fication. Since lidar and sodar systems are much smaller and lighter than tall towers,
they can usually be deployed at a far lower cost. For this reason, it is not uncommon
for them to be used to provide a first indication of the wind resource in a project area,
before the developer decides to invest in a purpose-built tower.
This section provides an overview of the various applications of surface-based
remote sensing, including vertical and side-scanning lidar and sodar. Satellite-based
radar, another remote sensing technology, is discussed later in this chapter.
Vertical Profiling Lidar. The use of vertical profiling lidar units offshore has
grown in recent years. If anything, lidar is more widely accepted offshore than on land
because the lack of terrain and low surface roughness allow for even closer agreement
with cup anemometers, the standard for defining wind turbine power curves.
Lidars can be deployed on many types of fixed platform, including jack-up barges.
They must be carefully placed and configured to ensure good accuracy and data
quality, however. The specific requirements depend in part on the type of system.
In general, a lidar should be placed where other platform elements, such as towers,
maintenance buildings, and moving equipment such as anemometers and wind vanes,
will not create interference. It also needs to be accessible for periodic maintenance.
Additionally, some lidar units use onboard meteorological sensors as an input to their
data processing, and it is important that they be well exposed to the environment.
Although it is cheaper to deploy a lidar system on a fixed platform than to install
a tall tower, it can nonetheless be an expensive and time-consuming process. A
promising alternative approach is to place the lidar on a floating platform or buoy