Page 146 - Solar Power in Building Design The Engineer's Complete Design Resource

116 INTRODUCTION TO SOLAR POWER SYSTEM DESIGN

Mean shading multiplier = (7 + 15 + 35 + 49 + 88 + 89 + 89 + 90 + 92 + 97 + 97)/
12 = 54%

Applying the dc-to-ac loss (0.77%) and mean shading multiplier to the calculated
PTC, we obtain
Net ac output watts = (79,285 W PTC) × 0.77 (ac-to-dc loss) × 0.54 (shading
multiplier) = 32,966.7 W

According to the preceding performance result, the effective energy production is
reduced to such a degree that the return on investment of the solar power program will
be hardly justified. To mitigate this problem the solar power platform must be reduced
to the unshaded area.
The preceding solar power calculation should serve to caution design engineers to
perform a comprehensive preliminary feasibility study prior to submitting the rebate
application forms; otherwise, a substantial reduction in projected power production
capacity could create many adverse consequences that may result in unnecessary budget
overruns, project execution delays, rebate incentive application updates, and client
dissatisfaction.