Site IV.3

Health
COD
2014
Nominal Capacity
50 kWp
Yield since COD
941 kWh/kWp
Possible Gain
6% to 20%
CAPEX, OPEX
1.1 ₹/Wp, 0.3 ₹/Wp/a

Abstract

The PV plant is affected by PID problems. The electroluminescence investigation showed some micro cracks with isolated cell areas. Furthermore, the DC wiring shows several damages. It is recommended to (i) stabilize the shaky mounting structure, (ii) implement anti-PID solutions, (iii) replace modules exceeding the manufacturer’s guaranteed performance drop and (iv) replace modules with defective J-boxes. The estimated production boost caused by the retrofitting actions lies between 6-20%.

Image gallery

Main Findings

The outer modules are installed on a very shaky mounting structure.
The modules present different types of J- box failure types, e.g., overheated, open or missing lid.
The cables of the irradiation sensor are not installed correctly.
Some parts of the cables are exposed to UV radiation. Some cable ducts are brittle and some have already broken.
String cables damaged by, or in contact with sharp edges were spotted.
Cable ties broke, hence the module cables and connectors are loosely hanging.
The connectors of the string cables on the inverters have fallen off.
Some cables are only connected with duct tape.
The thermographic examination showed some overheated plugs.
Several hot spots were discovered in the plant.

Impact on Performance

Soiling

Based on the measurements on-site, the soiling losses were determined to be 4.2%, on average.

Estimated Loss
≈ 4.2%
Potential Induced Degradation

First signs of a possible PID problem were recognized.

Estimated Loss
≈ 10%
Cell Cracks

The electroluminescence investigation confirmed the PID suspicion and showed further damage such as micro cracks and isolated parts.

Estimated Loss
≈ 5%
Near Shading

The simulation of the system showed a shading loss of 1.3%.

Estimated Loss
≈ 1.3%
Total Estimated Energy Loss
≈ 20.5%

Proposed Solutions

The mounting structure shall be retrofitted / strengthened.
An anti-PID measure, such as anti-PID box, should be implemented in order to stop or reverse the degradation.
All DC wiring should be properly maintained.
PV modules showing power drops above the warranty conditions should be replaced.
Modules with any defect on the J-box should be immediate replaced (safety, operation and reliability issues).