ing followed. Like PV power, PV panel heating coincid-
Table 4. High-visibility day PV panel performance.
ed with the sun declination angle. PV panel tempera-
ARO
Measured
Rated
tures experienced tens of degrees increases above ambi-
mounting
PV
output
output
ent South Pole temperatures at the highest sun declina-
location
panel
power (W)
power (W)
tion angle.
South Side
1A
26.8
51.0
1B
27.7
47.2
24-hour PV panel performance on a
1C
26.8
50.0
high-visibility day
1D
25.4
50.0
A 24-hour period on a high-visibility day (1112 Jan-
East Side
2A
49.7
51.0
uary 1998) was selected to compare the PV panels' per-
2B
50.2
47.2
formance (Table 4). Figure 11 begins with the south side
2C
51.9
50.0
of ARO receiving the unobstructed sunlight. As the 24-
2D
43.5
50.0
hour period progressed, peak PV panel performance
North Side
3A
50.1
51.0
changed as each side of ARO received direct sunlight
3B
49.4
47.2
(Table 5). The available PV power output levels listed in
3C
50.8
50.0
3D
42.6
50.0
Table 4 were chosen when the sun azimuth angle was
approximately perpendicular to the sides of ARO. For
West Side
4A
45.5
51.0
4B
47.0
47.2
three out of the four peak periods, PV panel C produced
4C
51.2
50.0
the highest available output power. PV panel D consis-
4D
44.1
50.0
tently produced the lowest available PV output power,
while panels A and B flip-flopped between second and
Table 5. Sun azimuth angle.
third, with the exception of the south side of ARO, when
PV panel B was first and A was second.
Grid angle
Time of greatest
PV
perpendicular
available
24-hour PV panel performance on a
panel ARO side
to ARO sides
power output
set designation
(degrees)
(hours)
low-visibility day
A 24-hour period on a low-visibility day (1314 Jan-
1
South
200
11001200
uary 1998) was also selected to compare the PV panels'
2
East
110
17001800
3
North
20
23000000
performance (Table 6). During this 24-hour period, the
4
West
290
05000600
visibility at the south pole was recorded as being 0.25
miles or less. Figure 12 begins with the south side of the
ARO receiving the obstructed sunlight. The available
bility increased and sun faced the north side of ARO,
output power of all the PV panels remained low during
there was greater available output power from the PV
this period. Because of the low visibility, it was difficult
panels. PV panel C produced the highest available out-
to identify any particular PV panel as outperforming the
put power, while PV panel D produced the lowest. PV
next. At the end of the 24-hour period, when the visi-
panels B and A came in second and third.
60
360
Azimuth
North Side
Panel 3
A
East Side
300
50
B
Panel 2
C
D
240
40
South Side
180
30
Panel 1
120
20
West Side
Panel 4
60
10
0
0
11 Nov 1998
12 Nov 1998
13 Nov 1998
Noon
Noon
Midnight
Midnight
Midnight
Figure 11. PV panel performance on the high-visibility day (11 to 12 Janu-
ary 1998) over 24 hours.
8
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