Site 2.27

Site ID
Nominal Capacity
109 kWp
Average Specific Yield
678 kWh/kWp
Total Estimated Loss
Possible Gain
35% to 40%
1.19 ₹/Wp, 0.48₹/Wp/a
Expenditure / Energy
2.5 ₹/kWh to 2.2 ₹/kWh


Heavy soiling was observed. Cables with bite marks and missing string labelling were found. Several modules show presence of PID. It is recommended to (i) increase cleaning cycles, (ii) replace the cleaning equipment used, (iii) install anti-PID box to mitigate damages from PID, (iv) re-sort PID affected modules, and (v) install a weather station or at least an irradiation sensor on the module plane to quantify and monitor the performance ratio. The estimated production boost expected by the retrofitting actions is expected to be around 35% to 40%.

Image gallery

Main Findings

Poor cable management: The minimum cable bending radius is not respected. In addition, table and string labelling are missing. Cables showed signs of bite marks.
Several modules are shaded by a taller room, tower, water tank, parapet walls, and PVC pipes.
The contacts in the earthing strips between tables are rusted.
The inverter fans and filters are soiled.
The Surge Protection Device (SPD) and fans in some inverters have also failed in operation.
The inverter room is poorly ventilated.
Modules are heavily soiled.
Modules are installed beyond roof boundary in high wind zone.
During inspection, many modules with bent frames were seen due to installation over pipelines.
IR analysis indicates presence of PID in the modules.

Impact on Performance

Heavy Soiling
The system performance was affected by soiling loss of 28%, estimated from IV curve measurements.
Estimated Loss
≈ 28%
Cell Cracks
The EL image also reveals that the modules are severely affected by PID. EL findings also show presence of cracks, isolated cell parts, and finger interruptions
Estimated Loss
≈ 12%
Based on the IV curve measurements, the estimated underperformance is 35% for the measured modules.
Estimated Loss
≈ 34.8%
Near Shading
Estimated Loss
≈ 3.97%
Self Shading
Estimated Loss
≈ 3.98%
Inhomogeneous tilt angle
Estimated Loss
≈ 0.1%
Total Estimated Energy Loss
≈ 82.85%

Proposed Solutions

Strings, tables, and inverters should have suitable labelling (UV-resistant if applicable). Appropriate protection of cables from animals shall be provided.
The cleaning cycles shall be increased based on the results of a soiling study.
The inverter filters and fans shall be cleaned. Faulty components in the inverters shall be replaced.
Inverter room shall be properly ventilated.
A re-sorting shall be conducted to have the lower performing modules in the same string at least same MPPT.
A re-stringing shall be conducted to have shaded modules in the same string or at least same MPPT.
An anti-PID installation shall be done to reduce performance loss and further module damages from PID.
A weather station, or at least an irradiation sensor on the module plane shall be installed.
Installation over pipelines shall be moved, or the pipeline shall be rerouted, and the modules with bent frames shall be replaced to prevent any safety threats.
Rusted joints and components should be replaced if possible. To prevent such problems, metal objects vulnerable to corrosion can be painted with zinc.