WIND ENERGY SYSTEMS - Cd3wd

Chapter 8—Economics 8–27
Rated Rated Propeller
Output Wind Speed Diameter
Model (W) (m/s) Voltage (m) Cost
A 1200 10.3 dc 3.0 $1695
B 1800 10.7 dc 3.5 $1940
C 2500 11.2 dc 3.8 $2380
D 4000 10.7 dc 4.4 $2750
E 6000 13.4 dc 5.0 $3275
F 1200 10.3 ac, single-phase 3.0 $2045
G 2000 11.2 ac, single-phase 3.5 $2475
H 3500 10.3 ac, three-phase 4.2 $3450
I 5000 10.3 ac, three-phase 5.0 $3840
9. You can buy a truck with a diesel engine for $500 more than the identical truck with
a gasoline engine. You estimate you will get 25 miles per gallon with the diesel engine
and 20 miles per gallon with the gasoline engine. Both gasoline and No. 1 diesel oil sell
for $1.50 per gallon at the present time and you estimate a real escalation rate of 0.08
over the next several years. You hope to drive the truck 100,000 miles during the next
seven years with no difference in maintenance costs between the cars. If inflation is 0.10
per year and interest is 0.14 per year, determine the present worth of the diesel oil and
gasoline needed over the seven year period. Which truck is the economical choice?
10. A utility is considering installing a number of wind turbines with a total rating of 1000
MW in its service area. The assumed capacity factor is 0.32 and the effective capacity is
0.28. These will displace a coal fired turbine with effective capacity 0.8. The coal plant
costs $900/kW in Year 0 dollars and the price of coal is $1.35/10 6 Btu. Operation and
maintenance costs of both the coal plant and the wind plant are $3.00/kW/year fixed
costs and 1.10 mills/kWh variable costs (at year 0). The heat rate is 10,000 Btu/kWh.
The levelized capacity factor of the coal plant is 0.7. The levelized fixed charge rate is
0.19, inflation is 0.07, and cost of capital is 0.11.
The plant life of both the coal plant and the wind generator is 30 years. System reliability
is to be maintained at the same level with either the wind or the coal generation. Any
difference in energy production is to be obtained by burning more or less coal at other
coal generating plants. How much can the utility afford to pay for the wind turbines?
References
[1] H.J. Allison: Final Feasibility Report - An Energy Center in Sri Lanka, prepared for
the Governing Council of the United Nations Environment Program by the Engineering
Energy Laboratory, Oklahoma State University, Stillwater, Oklahoma, June 30, 1976.
Wind Energy Systems by Dr. Gary L. Johnson November 21, 2001