The Challenge
A facility installed a 300 kWp solar array expected to generate 120 kWh daily with 0.8% annual degradation. After 18 months, the facility's energy manager noticed something unusual in the quarterly reports: generation was trending down faster than expected.
What Became Visible
Detailed performance analysis comparing actual output to modeled expectations revealed that the array was degrading at 3.2% annually — 4× the industry standard. The root cause: a batch of panels from one manufacturer in the array had inherent defects leading to accelerated light-induced degradation (LID). Without month-to-month performance tracking, this would have gone unnoticed until year 3 or 4, resulting in ₹30+ lakhs in cumulative lost generation.
What Changed
Monthly performance comparison of actual output vs. modeled output, with string-level performance tracking to identify which sections were underperforming.
How it worked: Performance degradation was quantified and attributed to specific panels. The manufacturer was contacted with performance data as evidence of defect. Replacement panels were negotiated and installed. Annual degradation returned to 0.9%, eliminating the future loss trajectory.
Results
instead of year 3–4
over 10-year panel life
backed by performance data
Panel degradation is not uniform. Defective batches degrade 3–4× faster than standard panels. Without performance tracking, this accelerated loss is invisible until substantial. Early detection allows warranty claims and replacements before losses compound.
Operational Reality
Most solar arrays with degradation issues go undetected for 3–5 years. The arrays with monitoring systems detect issues within the first 12 months.