WIND ENERGY SYSTEMS - Cd3wd

Chapter 9—Wind Power Plants 9–34
Table 9.12. Estimates of other costs for Kansas.
Land.
About $400 per acre for grazing land and $800 per acre
for farm land. This includes a premium over present
costs which may be necessary to get the good sites.
Foundations.
Concrete costs between $40 and $50 per cubic yard
delivered to the site. Installed cost, including
steel, may be close to $100 per cubic yard.
Access Roads. About $6 per linear foot for places where
extensive grading is not required. Western Kansas is less
expensive, perhaps $1 per linear foot.
Visitor Center. $100,000 should be adequate.
Maintenance Building. $150,000.
Meteorological Tower. $6000 or more.
Fence.
$2/ft for barbed wire, $6/ft for 6 ft tall 9 gauge
chain link plus $1/ft for 3 barbed wires on top.
Crane. Winch and cable 50 ton $500,000 or hydraulic $600,000.
Rental cost $150/hr or $4000/week.
Rental includes operator but does not include travel.
Bulldozer.
Clearing brush $1500/acre, or $110/hr for D-8.
Labor.
Estimate at least $15/hour for skilled labor.
10 PROBLEMS
1. An underground loop is being designed for a windfarm that will carry 8 MVA at a
voltage of 13.2 kV line-to-line. Compare the installed costs of the loop for the one- and
two-circuit cases.
2. A wind turbine is rated at 110 A, 480 V, three-phase, 91.5 kVA, and 80 kW. It is to be
connected by single-circuit underground aluminum conductors to a transformer 300 ft
away.
(a) What is the minimum wire size according to Table 9.2?
(b) What is the rated current of this wire?
(c) What is the power loss in the three phase conductors between turbine and transformer
under full load conditions, in watts and also as a fraction of the rated
power?
(d) What wire size would you select to reduce the fractional loss of the previous part
to less that 2 percent?
3. A three-phase transformer rated at 750 kVA, 480/12470 V has no load losses at rated
voltage of 1112 W and copper losses at rated current of 5184 W. What are the total
transformer power losses when it is operating at 60 percent of rated current and 95
percent of rated voltage?
Wind Energy Systems by Dr. Gary L. Johnson November 21, 2001