It appears in Figure 7 that only a very small Me product is required for a sufficiently small N' (or N), in order to meet all the constraints. However, a small N implies a small Biot number and higher absorber temperatures, and an attendant small surface area to limit receiver losses. This is illustrated by the calculations in Table 1 where for S = 0.85, As was obtained from 3 in Figure 4 and % from Figure 7, with other quantities from definitions.
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