13 Anomalies, 10,967 Modules Affected
3434 kW, 4.37% Affected
$184,731 Lost if Anomalies Unresolved
This 79 MW PV system was inspected before the annual preemptive maintenance visits. A drone with a thermal camera was flown and photographed every panel in one day. This site was found to be heavily impacted by over 13 types of PV system anomalies, with over 10,000 offline modules. The largest and most impactful issue identified was the 50 inverter faults, amounting to over 4% of annual production loss.
On top of the 50 inverter faults, the inspection identified 8 offline strings which were estimated to reduce production capacity by 84 kW. There were also 64 module level issues and 594 sub-module level anomalies. These reduced the PV system’s production by 95 kW from the site’s full operating capacity.
The operations and maintenance team knew that the site was facing inverter issues due to internal monitoring signals, but the number and location of them were unclear. Upon the report being delivered, the vendor prioritized their onsite task to resolve the various inverter faults causing the 4% daily performance loss. The inspection report equipped them with the data needed to deploy the necessary number of technicians and resources to the affected areas of the PV system.
| Anomaly Type | Anomaly Amount | Modules Affected | Est. Affected DC (kW) | Est. Affected DC (%) | Est. Annual Impact (kWh) | Est. Annual Impact ($) |
|---|---|---|---|---|---|---|
|
Cell |
284 |
284 |
30 kW |
0.04% |
66,141 kWh |
$1,653 |
|
Cell Multi |
241 |
241 |
39 kW |
0.05% |
84,199 kWh |
$2,104 |
|
Cracking |
3 |
3 |
1 kW |
0.00% |
2096 kWh |
$52 |
|
Diode |
67 |
67 |
7 kW |
0.01% |
15,603 kWh |
$390 |
|
Inverter |
50 |
10034 |
3261 kW |
4.15% |
7,011,257 kWh |
$175,281 |
|
Module |
35 |
35 |
11 kW |
0.01% |
24,456 kWh |
$611 |
|
Shadowing |
14 |
14 |
1 kW |
0.00% |
3260 kWh |
$81 |
|
String |
8 |
261 |
84 kW |
0.11% |
182,373 kWh |
$4,559 |
|
Totals |
702 |
10939 |
3434 kW |
4.37% |
7,389,385 kWh |
$184,731 |
1884 Anomalies, 2,400 Modules Affected
320 kW, 2.64% Affected
$17,427 Lost if Anomalies Unresolved
This site was inspected because of underperformance based on recent monitoring signals. Using a drone and thermal imaging camera, the site was flown and data was been uploaded for automated processing to receive an inspection report. The findings uncovered 1,826 anomalies, falling into 9 categories, with 2,400 modules affected. The report identified and located 10 malfunctioning strings, 379 diode faults, and over 400 cases of vegetation across the plant. The annual loss of production from the anomalies identified would total more than 600,000 kWh.
The PV System manager used the reports and the visual spectrum images from the inspection to assess all 400 cases of vegetation and were able to instruct their vegetation management vendor to the exact locations for removal. The manager also deployed field technicians to investigate the high number of modules affected by diode faults and remediate the 10 string anomalies impacting 0.5% of system performance. Along with this improvement, the PV System manager continued to utilize aerial preventative maintenance inspections regularly to maintain optimal site conditions.
| Anomaly Type | Anomaly Amount | Modules Affected | Est. Affected DC (kW) | Est. Affected DC (%) | Est. Annual Impact (kWh) | Est. Annual Impact ($) |
|---|---|---|---|---|---|---|
|
Cell |
457 |
457 |
47 kW |
0.39% |
103,157 kWh |
$2,578 |
|
Cell Multi |
586 |
586 |
92 kW |
0.75% |
198,434 kWh |
$4,960 |
|
Cracking |
11 |
11 |
3 kW |
0.03% |
7449 kWh |
$186 |
|
Diode |
379 |
379 |
39 kW |
0.32% |
85,550 kWh |
$2,138 |
|
Module |
3 |
3 |
1 kW |
0.01% |
2031 kWh |
$50 |
|
Shadowing |
26 |
350 |
36 kW |
0.30% |
79,004 kWh |
$1,975 |
|
String |
10 |
190 |
59 kW |
0.49% |
128,677 kWh |
$3,216 |
|
Vegetation |
412 |
412 |
43 kW |
0.35% |
92,999 kWh |
$2324 |
|
Totals |
1884 |
2388 |
320 kW |
2.64% |
697,301 kWh |
$17,427 |
442 Anomalies, 2,853 Modules Affected
378.21 kW, 6.56% Affected
$17,447 Lost if Anomalies Unresolved
This 5.9 MW PV system was inspected as part of an annual preventative maintenance protocol. A drone was flown for three hours and provided the operations and maintenance team with sub-modular anomaly details through thermal and visual spectrum imagery. The inspection showed anomalies from the inverter level down to the cell level. The results uncovered 490 system anomalies, categorized into 16 anomaly types, and amounting to 2,853 affected modules.
The owner’s operations and maintenance team used the deliverables to identify the most impactful and easily remediated anomalies within the site. The report also enabled them to set up a plan to resolve all non shading related anomalies within two weeks of the site inspection. Next, the new data was used to create a plan to resolve the onsite issues causing the shading and performance loss.
| Anomaly Type | Anomaly Amount | Modules Affected | Est. Affected DC (kW) | Est. Affected DC (%) | Est. Annual Impact (kWh) | Est. Annual Impact ($) |
|---|---|---|---|---|---|---|
|
Cell Low |
37 |
37 |
3 kW |
0.07% |
7,201 kWh |
$180 |
|
Combiner |
52 |
324 |
103 kW |
1.78% |
189,216 kWh |
$4,730 |
|
Cell Medium |
12 |
12 |
1 kW |
0.02% |
2335 kWh |
$58 |
|
Cracking |
12 |
12 |
3 kW |
0.07% |
7,008 kWh |
$175 |
|
Diode Multi |
1 |
1 |
0.21 kW |
0.00% |
389 kWh |
$9 |
|
Diode |
68 |
68 |
7 kW |
0.12% |
13,236 kWh |
$330 |
|
Shadowing |
257 |
2297 |
244 kW |
4.20% |
447,104 kWh |
$11,177 |
|
String |
3 |
54 |
17 kW |
0.30% |
31,536 kWh |
$788 |
|
Totals |
442 |
2805 |
378.21 kW |
6.56% |
698,025 kWh |
$17,447 |
Case Studies Provided by The Drone Life’s Partner, Raptor Maps
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