Miami, FL or Atlanta, GA are considered for the installation of a solar power plant utilizing parabolic trough collectors. The total area of the collectors is 300,000 m2 and the average efficiency of the plant is estimated to be 18 percent. Using the average daily solar radiation values on a horizontal surface in Table 18-3, determine the amount of electricity that can be produced in each city.

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TABLE 18-3 Hourly variation of solar radiation incident on various surfaces and the daily totals throughout the year at 4o" latitude (from ASHRAE Handbook of Fundamentals, Chap, 27, Table 15) Solar Radiation Incident on the SurfaceWim Direction Daily Date Surface 56 7 8 9 10 11 noon 13 14 15 16 17 18 19 Total 12 Jan. N 0 0 020 43 66 68 7 68 66 43 200 0 0446 0 0 0 63 47 66 68 71 68 59 43 20 0 0 489 0 0 0 402 557448 222 76 68 59 43 20 0 00 1863 0 0 0 483 811 875 803 647 428 185 48 20 0 004266 0 0 271 579 771 884 922 884 771 579 271 00 5897 0 0 0 20 48 185 428 647 803 875 811 483 0 0 0 4266 0 0 0 20 43 59 68 76 222 448 557 402 0 0 1863 0 0 20 43 59 68 71 68 66 47 63 0 O 0 489 Horizontal 0 0 0 51 198 348 448 482 448 348 198 51 00 0 2568 NE SE SW NW Direct 0 0 0 446 753 865 912 926 912 865 753 446 0 0 Apr. N 0 41579 97 110 120 122 120 110 97 79 57 41 0 1117 0 262 508 462 291 134 123 122 120 110 97 77 52 17 0 2347 0 321 728 810 732 552 293 131 120 110 97 77 52 17 0 4006 0 189 518 682 736 699 582 392 187 116 97 7752 17 0 4323 0 18 59 149 333 437 528 559 528 437 333 14959 18 03536 0 1752 77 97 116 187 392 582 699 736 682518 189 0 4323 0 17 52 77 97 110 120 392 293 552 732 810 728 321 0 4006 0 17 52 77 97 110 120 122 123 134 291 462 508 262 0 2347 Horizontal 0 39 222 447 640 786 880 911 880 786 640 447 222 39 0 6938 NE SE SW NW Direct NE SE SW NW Direct 0 282 651 794 864 901 919 925 919 901 864 794651 282 0 July N 3 133 109 103 117 126 134 138 134 126 117 103 109 133 3 1621 8 454 590 540 383 203 144 138 134 126 114 95 71 39 0 3068 7 498 739 782 701 531 294 149 134 126 114 95 71 39 0 4313 2 248 460 580 617 576 460 291 155 131 114 95 71 39 0 3849 0 39 76 108 190 292 369 395 369 292 190 108 76 39 0 2552 0 39 71 95 114 131 155 291 460 576 617 580 460 248 2 3849 0 39 71 95 114 126 134 149 294 531 701 782 739 498 7 4313 0 39 71 95 114 126 134 138 144 203 383 540 590 454 8 3068 Horizontal 1 115 320 528 702 838 922 949 922 838 702 528 320 115 1 3902 7 434 656 762 818 850 866 871 866 850 818 762 656 434 7 Oct. N 0 0 7 40 62 77 87 90 87 77 62 40 0 0 453 0 0 74 178 84 80 87 90 87 87 62 0 70 0 869 0 0 163 626 652 505 256 97 87 87 62 40 7 0 0 2578 0 0 152 680 853 864 770 599 364 137 66 40 0 0 4543 0 0 44 321 547 711 813 847 813 711 547 321 4400 5731 0 0 740 66 137 364 599 770 864 853 680 152 0 0 4543 0 0 740 62 87 87 97 256 505 652 626 163 0 0 2578 0 0 7 40 62 87 87 90 87 80 84 178 74 00 869 Horizontal 0 0 14 156 351 509 608 640 608 509 351 156 14 0 0 3917 NE SW Direct 0 0 152 643 811 884 917 927 917 884 811 643 152 0 O Multiply by 0.3171 to convert to Btuh-ft Values gven are for the 21st of the month for average days with no clouds. The values can be up to 15 percent higher at high elevations under very clear skies and up to 30 percent lower at very humid locations with very dusty industrial atmospheres. Daily totals are obtained using 10-min time intervals. Solar reflectance of the ground is assumed to be 0.2, which is valid for old concrete, crushed rock, and bright green grass. For a speci- fied location, use solar radiation data obtained for that location. The direction of a surface indicates the direction a vertical surface is facing. For example, W represents the solar radiation incident on a west-facing wall per unit area of the wall. s rule for integ ation with Solar time may deviate from the lacal time. Solar noon at a lecation is the time when the sun is at the highest location land thus when the shadows are shortest). Solar radiation data are symmetric about the solar noon: the value on a west wall before the solar ncon is equal to the value on an east wall two hours after the solar noon.