Value chain · CLM-1036
In plain terms
The programme's own sizing arithmetic, with its rate of return stated: in the cases studied a bigger antenna always raised the cost, but much less if the ionospheric limit rose with it. The 152.3 in its cost formula is the capital-recovery factor for 15 per cent over thirty years.
The claim as recorded
NASA's 1980 sizing paper states the closed-form relationships between transmit antenna area, peak array power density, transmitted power and peak ground power density for a Gaussian taper, sizes the rectenna to capture 88 per cent, and costs each configuration at "a 15-percent rate of return on investment capital", "0.92 plant factor" and a 30-year life through the formula mills/kWh = 152.3 x system cost ($ million) / (8,050 x GW); the reference system is 59,984 t and $12,432 million at 47 mills/kWh, and enlarging the antenna to 1.36 to 2 km under a fixed 23 mW/cm2 limit raises electricity cost by 52 to 283 per cent, while the same antennas with the limit raised to 42 to 91 mW/cm2 raise it by only 11 to 43 per cent.
Evidence behind this: T3-programme office technical paper; equations stated in closed form and a costing basis stated.
Scope and limits
1977-DOLLAR COSTS BY SCALING FACTORS FROM THE BOEING REFERENCE (TABLE B-1), NOT RE-ESTIMATED; the paper's stated purpose is differential, not absolute, cost. Table 1 gives 2.72 GW for the 1.36 km case where Table 3 prints 2.7 and the conclusions page (printed 21) gives 2.76.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p.9, equations (1) and (2) from the render, which reproduce 6.76 GW against the reference 6.72 only at a peak array power density PD-ARRAY of 22 kW/m2, a value TP-1804 does not state: its printed 5 gives the thermal limit as 23 kW/m2, which puts equation (2) at 7.07 GW, and its Table 1 gives the reference's transmitted power as 6.5 GW. PDF p.14, raw: "15-percent rate of return on investment capital", "0.92 plant factor", "30-year". PDF p.15, raw: "59 984" metric tons and "$12 432" million. PDF p.31, raw: "152.3", "8050". Table 3, PDF p.16, from the render, raw "47". Arithmetic: CRF(15 per cent, 30 years) = 0.1523, so 152.3 is that factor times 1,000; 8,050 is 8,750 hours x 0.92 plant factor exactly, not 8,760 rounded (the page's 7,875 is 8,750 x 0.90).
Basis: mills/kWh at a 15 per cent rate of return, 0.92 plant factor, 30 years; 1977 USD
Related records
- Answers question
- QST-037 not published in this release
Cite this
energyaperture.com/c/clm-1036
CLM-1036, Energy Aperture, as of 1980-12.
Connected records
Other published records linked to this one. A list, not a judgement.
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