Distributed Renewable Energy Operating Impacts and Valuation Study

Solar Characterization
Figure 2-8: Typical Summer-Day Commercial PV System Electric Production Profiles
June 22, 2007
kW AC
80
70
60
50
40
30
20
10
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
1200
1000
800
600
400
200
0
W/m 2
Baseline (10-deg fixed) 0 Tilt One-Axis Horizontal
OPV2 One-Axis (actual)
STAR NIP1 (actual)
Figure 2-9: Typical Spring-Day Commercial PV System Electric Production Profiles
March 25, 2007
kW AC
80
70
60
50
40
30
20
10
0
1 3 5 7 9 11 13 15 17 19 21 23
1200
1000
800
600
400
200
0
W/m 2
Baseline (10-deg fixed) 0 Tilt One-Axis Horizontal
OPV2 One-Axis (actual)
STAR NIP1 (actual)
The commercial data show that during the summer (June 22), the rate of electric production for
single-axis tracking is fairly flat but during the spring (and fall, which is not shown), the system
production dips at the time when the fixed array is peaking. Note that a comparison of the
modeled tracker system to the actual tracker system at the beginning and end of the day is not in
complete agreement. The actual tracker system is impacted by control sequences that take into
Distributed Renewable Energy Operating Impacts & Valuation Study R. W. Beck, Inc. 2-13