Site II.9

Health
COD
2017
Nominal Capacity
105.71 kWp
Yield since COD
1233 kWh/kWp
Possible Gain
17% to 22%
CAPEX, OPEX
4.4 ₹/Wp, 0.5 ₹/Wp/a

Abstract

The PV plant shows extreme soiling caused by smog and dust. Lack of structural integrity of the sheet metal roofing and mechanical damages at the module level were also observed. It is recommended to (i) increase the cleaning frequency to at least three times per month, (ii) replace and/or install UV cable protection means (iii) reinforce the structural integrity of the roofing material (iv) rearrange the modules based on the damage categories and (v) restring the circuits based on the shading conditions. The estimated production boost expected by the retrofitting actions lies between 17% and 22%.

Image gallery

Main Findings

Pipes carrying cables are brittle and some parts have already broken, exposing cables to UV radiation. The colors have already started to fade.
Delamination and cell corrosion were observed on the front side of the modules.
Heavy soiling has been detected on site. The dense traffic (smog) in the street next to the system increases the dust accumulation on the modules.
There is no weather station in any part of the system and hence, no PR monitoring.
Electroluminescence imaging confirms the presence of cell damages caused during the installation and O&M activities.
The roof supporting structure is not entirely robust.
Cables hanging above the system cast shadows onto the modules throughout the day.

Impact on Performance

Soiling

Soiling losses in the parking section at the Municipal HQ were calculated in 19% on average.

Estimated Loss
≈ 19%
Cell Cracks

The EL images show a few cracks on the inspected modules. This could result in a performance loss of 4% at the system level.

Estimated Loss
≈ 4%
Near Shading

The simulation shows shading losses caused by the cables of 1.5%.

Estimated Loss
≈ 1.5%
Total Estimated Energy Loss
≈ 24.5%

Proposed Solutions

The structural integrity of the roof shall be reinforced. The cables shall be protected from UV radiation by robust pipes or tubes.
A weather station, or at least an irradiation sensor on the module plane, shall be installed so that the performance of the system can be properly determined.
Manual cleaning shall be implemented and re-scheduled based on the results of a soiling study that adjusts the cleaning needs to each season.
Modules with heavy cracks shall be grouped in the same string or at least assigned to one MPPT. The grouping will be conducted based on infrared inspection with high irradiation levels and after cleaning. Modules with similar shading conditions shall be installed in the same string or at least assigned to one MPPT.