All the above data are summarized in Figure 9 where unit collector cost is shown versus the aperture diameter. Lines of constant cost per unit area are shown (5, 10 and $25/ft2 ) which represent the three ranges of estimates discussed above. The cost estimate for one-piece fabrication is near the $5/ft line and is considered to be valid up to a 22 foot diameter (upper limit shown in Figure 9). At sizes greater than this, it is necessary to switch to a technique similar to suggestions by JPL or the Honeywell team. The lower limit for the JPL technique of bending the glass is shown near the 30 foot diameter. The Honeywell-Black and Veatch approach seems to span these two fabrication regions. Above some particular size, the cost shows a diameter to the cube power dependency suggested by experience of the deep space network of JPL/NASA. It is not clear at what specific size there is a transition from a diameter squared to diameter cubed relationship. Superimposed on the Figure 9 curves of constant $/ft2 is a diameter cubed curve. Based on the preceding information, a likely collector cost was estimated and is indicated by the heavy line in Figure 9. The cost model is as follows based on 1974 dollars. - Cost — $10/ft2 for 1 to 15 foot diameter - Cost = f(D^3) at diameter > 36 ft - Cost curve passes through $11.50/ft2at 36 foot diameter - Smooth transition from D2 to D3 lines between 15 and 36 foot diameter This is very preliminary, but shows the dependency on size of this type of collector. Thus, there is a range of cost estimates from $5.35/ft2 to $24/ft2 for dish parabolic collectors with relatively similar performance (surface reflectivity and total aiming accuracy). This factor of 5 uncertainty indicates the rather preliminary nature of the current status of evaluation. Most probable costs are in the $10/ft2 to $15/ft2 range based on limited current data.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==