The correct answers are:
South Texas: 305 W/m2
northern U.S.: 256 W/m2
northern U.S. (winter): 115 W/m2
These the results are, respectively: 959 W/m2 / pi; 805 W/m2 / pi; and (451 W/m2 / pi) * 0.8.
These results would be the average available energy only if there were a method to convert 100% of this flux to useful power. In reality, perfect efficiency in converting solar energy to useful power is unattainable. The best efficiency of commercially-available solar photovoltaic collectors (i.e. collectors that are cheap enough to be cost effective) is 16%. The best efficiency for any laboratory solar cells is 30%.
Using the more optimistic value of 30%, find the average power that can be harnessed for each location from above.
How do your answers compare to the 1,368 W/m2 you started with?
What additional factor have we ignored?
Click here to check your answers and continue...
© 2001-2002, 2005 by Wm. Robert Johnston.
Last modified 11 January 2005.
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