Page 344 - Fluid Power Engineering

304 Chapter Fourteen

methods of measurement (met-towers, SODAR, and LIDAR),
type of equipment and sensors, and the mode of measure-
ment are determined. If SODAR and LIDAR are used, then
the option of relocating to measure at multiple sites is avail-
able. If this option is availed, then an itinerary of locations
must be determined. The cost of traditional 60-m met-tower
with standard set of instruments, data-logger and communi-
cation equipment, installation, and decommissioning is about
$35,000. Other approximate costs in 2010 are: An 80-m tower
is an additional $5,000; higher quality instruments will cost an
additional $3,000; SODAR unit is about $45,000 to $50,000 for
the basic unit, and additional $10,000 for trailer; LIDAR unit
is $120,000–$150,000. In situations where the high quality of
wind resource is known and planned wind project is large,
then a few permanent met-towers may be installed.
Land lease and permitting. Land lease during wind measure-

ment is typically $2000–$5000 per year. Two types of agree-
mentsaresignedwiththelandowner:Windmeasurementand
options.Inmostcases,thedeveloperseeksanexclusiveoption
for a period of 2 to 7 years to measure wind speed, perform
geotechnical tests, survey land, and other related activities.
The exclusivity clause will prevent the landowner from leas-
ing land to other developers and may place restrictions on the
nature of information that can be divulged to others. Projects
with towers higher than 60 m are required to file a request
with the FAA (see Chapter 11). In addition, local permits may
be required to erect temporary structures, like met-towers.
Met-tower installation and commissioning. This activity may take

2–3 days and a four to five-member crew. Since met-towers
cannot be erected during conditions of high wind and gusts,
wind forecasts must be checked before scheduling a met-
tower installation. Under perfect conditions and very expe-
rienced crew, a met-tower may be installed in a day. After the
installation is complete, commissioning involves checking if
the wind measurement data is being logged, transmitted, and
received. The first few hours of data must then be thoroughly
reviewed and validated against concurrent data from neigh-
boring airports or weather stations.
Wind data management and reporting. A standard practice is

to receive daily wind data by email, which is automatically
inserted into a database with a variety of checks and filters.
Web-based reporting is then available to view data in a variety
of reports.
Decommissioning of Met-towers. After the wind measurement

campaign, the land is returned to its previous state. Since most