Broken modules still connected to strings at a Rajasthan plant
Saur Energy article on solar diagnostics · 21 MW plant, Rajasthan
The situation
Damaged and broken modules were suspected at the plant, and some were still connected to their strings.
Background
A broken module left in a string can drag down the whole string and become a hotspot or safety risk. At 21 MW, walking every row is slow, so a combination of sampling and aerial scanning was used.
What was tested, and how that method works
EL and thermal imaging of 1,829 modules, plus drone-based thermography of the plant.
Thermal imaging records surface temperature. A cracked or shaded cell that is dissipating power shows up hotter than its neighbours. A drone makes it practical to cover a whole plant. EL imaging is used on a sample to see the cell-level cause.
Our service: Thermography →What was found
- About 0.28% of modules were severely damaged and about 4.6% moderately damaged.
- 115 of the 1,829 imaged modules showed hotspots.
- Drone thermography found 130 broken modules still in strings, about 144 kWp combined, with a net plant impact of about 18 kWp.
How it unfolded
Outcome
The article does not report what was repaired afterwards.
Lessons for a plant owner
- Sampling with EL and sweeping the whole plant with drone thermography find different things. Together they give a fuller picture.
- A broken module left connected can be a safety issue as well as an energy loss.
- The reported net impact (about 18 kWp) was small compared with the combined size of the broken modules. Context matters when judging loss.
Questions to ask about your own plant
- Which broken modules are still connected in our strings?
- When was the last whole-plant thermal sweep?
- Do our reports separate cosmetic damage from electrical damage?
How we would approach a similar site
We would pair a sampled EL check with a thermal survey of the whole plant, and list modules to replace.
Figures are as reported in the article. The plant owner is not named. Source: Saur Energy. Summarised in our own words.