Civil Engineering Reference
In-Depth Information
TIR = Tax and insurance rate per year as a fraction of the ICC
OMC = Operating and maintenance cost per year
EDF
= Energy delivery factor over one year, as defined earlier
kW
= Kilowatt electrical power capacity installed
The amortization rate AMR reflects the cost of money, generally taken as
0.10 to 0.20 depending on the prevailing mortgage interest rates available
for such a project. The energy delivery factor EDF accounts for the variations
in the impinging energy (sun intensity or wind speed) at the proposed site,
and all downtimes, full or partial. It is also a strong function of the reliability
and maintainability of the plant over the entire year.
The present costs of various energy sources are summarized in
Table 15-3
.
It shows that the wind power now compares well with the conventional coal
thermal power.
15.5
Sensitivity Analysis
Accurately estimating the cost of electricity produced is not sufficient. The
project planners must also carry out the sensitivity analysis, in that the
energy cost is estimated with a series of input parameters deviating on both
sides of the expected values. The sensitivity of the energy cost on the fol-
lowing two factors is discussed in this section:
•
variation in the wind speed.
•
variation in solar irradiation.
15.5.1
Effect of Wind Speed Variations
Since the energy output of the wind plant varies with the cube of the wind
speed, a several percent change in the speed can have significant impact on
TABLE 15-3
Energy Generation Cost with Various
Power Technologies
Generation Cost
(Fuel + Capital)
U.S. cents/kWh
Plant Technology
Wind Turbines
5-7
Solar Photovoltaics
15-25
Solar thermal (Solar II type)
8-10
Coal Thermal (Steam-Turbine)
3-4
Combined Cycle Gas-Turbine
5-7
