Question

PV-panel panel normal vector has following azimuth and elevation angle

	Azimuth α	Elevation ε
Panel normal vector	180o	45o

Sun azimuth and elevation angle are given in different time below

Hour	Azimuth α	Elevation ε
5:00	54.09o	3.32o
8:00	92.43o	23.80o
13:00	178.69o	48.53o
17:00	252.09o	31.88o
21:00	304.39o	4.18o

At what time the PV-panel power output is highest?

Select one:

a. 21:00

b. 17:00

c. 13:00

d. 5:00

e. 8:00

Answer 1

A PV panel refers to a photo voltaic panel.

The azimuth and elevation angle of the PV panel in this case is given as- 1800 and 450.

Now Solar Panels usually produce 250-400 watts of power, on a daily basis. On an average. Now the azimuth angle is defined as the compass direction from which the sunlight is coming.It is usually measured with respect to the object under consideration, that is in this case, the PV solar panels. The azimuth angle is measured with respect to the surface upon which the panels are placed. In other words, the angle is calculated from the elevation of the Solar Panel. Now usually the Sun makes an azimuth of about 90 degrees during Sunrise and 270 degrees during Sunset. Now if we refer to the given table of the Sun's azimuth and elevation, we notice that at 05:00 hours the azimuth is not 90 degrees yet, which is suggestive of the fact that Sunrise hasn't taken place at that corresponding geographical place yet. We notice that the azimuth of the Sun is around 92 degrees at 08:00 hours, which suggests that Sunrise may have taken place at the time period of around 07:00-07:30 hours. Now if we consider the time of 17:00 hours and 21:00, the azimuth angles during this time are 252 and 304. This refers to the fact that at 17:00 hours, the Sun is nearing sunset and at 21:00 hours, it has already set, at that geographical place. So, the timing of 13:00 hours or 1 pm is the time, when the PV Panel Power Output is the highest. The angle of elevation is around 178 degrees. which suggests that it almost overhead the PV panel, and hence the sunlight received by the panel during this time is quite significantly high as compared to the other timings given. Hence, option C is the correct alternative.