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ECONOMIC ANALYSIS 987
5
4.48
Required module price
[1985$/Wp]
4
3
2
1
3.46
4.06
2.18
1.9
1.23
1.33
1.15
1.03
1.22
0.9
0.93
0.76
0
Pessimistic case Base case Optimistic case
Cell technology and process case
Czochralski DendriticWeb 500X Concentrator a-Si:H a-Si:H/a-SiGe:H
Figure 21.3 Required module price for silicon-cell technologies [3]. Copyright © 2002. Electric
Power Research Institute. EPRI AP-4369. Photovoltaic Manufacturing Cost Analysis; A Required
Price Approach, Vol. 1, 2. Reprinted with Permission
Table 21.3 Czochralski module prices for process and financial
cases (1985$/W p )
Process cases
Pessimistic Base Optimistic
Pessimistic 1.98
Financial cases Base 3.46 1.90 1.22
Optimistic 1.80
This relationship results from the fact that material costs are a large fraction of the
required module price, 44.2% for the Czochralski base case, whereas the cost of the
required capital for machinery and equipment, which is usable over several years, is a
much smaller fraction of the price.
A sensitivity diagram, such as Figure 21.4 for the Czochralski module, illustrates
the relative effect of individual process or financial-parameter values on the required
module price. Here, the module-price variations for each parameter are plotted with respect
to the parameter expressed as a percent of its base-case value. The slopes of the lines are
then the price sensitivity to each parameter. For the Czochralski module, the price is most
sensitive to the achieved conversion efficiency and the unit cost of the silicon boule. The
price is much less sensitive to the unit cost of the glass sheet, wafer thickness, and return
on equity (a financial parameter equivalent to the profit for the module manufacturer).
Sensitivities for the other cell technologies follow a similar pattern.
One of the most useful results of the study is the illustration of the trade-off
between the silicon-utilization and cell-conversion efficiency as reflected in the module
price. Figure 21.5 shows the effect of efficiency on the base-case prices for all five cell