Question

1. You have installed a photovoltaic array in front of your small home on 4th Avenue in Nome, Alaska. Now, Kawerak, Inc. has plans for a high rise building of three stories across the narrow street. You have looked at the plans and determined the rectangular building will block from +20 degrees to +80 degrees azimuth and 40 degrees altitude. How many hours of sunlight will be the building block in April or August. Refer to the 65.5 N Latitude sunpath diagram included with the quiz.

Answer in hours to the nearest tenth of an hour.

Answer 1

To solve this kind of problem, we need to find the hour angles for different azimuths and then subtract the extremum value.

we know that

where z - zenith distance =

A- Azimuth

H- Hour angle

	z - zenith distance	A- Azimuth	H- Hour angle(in Degree)	H- Hour angle( in Hour)
		+	-83.53365	5.54313
		+	-80.22757	5.32374
	​​​​​​​	+	-76.83217	5.09843
	​​​​​​​	+	-73.31459	4.86501
	​​​​​​​	+	-69.63943	4.62114
	​​​​​​​	+	-65.76822	4.36425
	​​​​​​​	+	-61.65923	4.09158

Hour angle difference = 5.54313 - 4.09158 = 1.45155 hour.

The sunlight will be blocked by 1.45 hours by that building.