What causes hotspots on solar panels in Pakistan?

The most common causes in Pakistan are: permanent bird droppings (kawa / kabootar waste), fallen leaves, partial shading from overhead water tanks or TV antennas, cracked solar cells (from careless workers stepping on panels during cleaning), and failed bypass diodes.

How can I detect hotspots on my solar panels?

Hotspots can be detected using an infrared (IR) thermal imaging camera or thermal drone during peak sunny hours (12:00 PM to 2:00 PM). Defective cells show up as bright yellow/red glowing spots significantly hotter (30°C+ hotter) than surrounding normal cells.

Maintenance & Safety

Solar Panel Hotspots in Pakistan 2026: Causes, Fire Risks & Prevention

Q: What is a hotspot on a solar panel?

A hotspot occurs when a single shaded or defective solar cell becomes reverse-biased, turning from an electricity generator into an electrical resistor. Instead of producing power, it consumes power produced by the rest of the string, heating up to 150°C–200°C and scorching the plastic backsheet, melting EVA glue, or causing rooftop fires.

By PSI Editorial · 7 min read · Updated September 2026

Thermal hotspot on solar panel cell causing burn marks on backsheet in Pakistan — PakSolarInsights

Atomic Summary: Hotspots are localized areas of extreme heat on a solar panel that can exceed 180°C, permanently destroying silicon cells and creating severe rooftop fire hazards. In Pakistan, the leading causes are dried bird droppings, partial shadow from water tanks, and technicians walking on panels during cleaning. Prevent hotspots with bi-weekly washing, half-cut cell technology, and annual thermal IR camera audits.

How Hotspots Form: The Reverse-Bias Phenomenon

In a standard solar string, all cells are wired in series like a chain. Current must pass through every cell. When a single cell is covered by a bird dropping or shadow, it stops producing electricity:

The unshaded cells in the string force high DC current (up to 14 Amps) through the shaded cell.
Because the shaded cell cannot conduct freely, it acts as a localized electrical bottleneck (resistor).
Power is dissipated as intense concentrated heat (I²R loss), causing localized temperatures to rise above 150°C within minutes.

How to Prevent Hotspots on Pakistani Rooftops

Never Walk or Rest Knees on Solar Panels: Technicians walking across panels create microscopic silicon fractures (micro-cracks) invisible to the naked eye that develop into severe hotspots within 6 months.
Clean Bird Droppings Promptly: Inspect your array weekly; dried pigeon and crow droppings create localized blind spots that force cells into reverse bias.
Choose Half-Cut Multi-Busbar (MBB) Panels: Modern half-cut panels (Jinko, LONGi, Canadian Solar) feature 3 bypass diodes and 16+ busbars, halving internal current and drastically reducing hotspot temperatures.
Eliminate Obstruction Shadows: Prune tree branches and ensure TV satellite dishes or overhead water tanks are positioned north of the array so they never cast shadows across panel rows.

Frequently Asked Questions

What is a hotspot on a solar panel?

A hotspot is an overheated cell that has stopped generating power and is instead burning electricity from adjacent cells, causing scorching or fire risks.

Does manufacturer warranty cover hotspot damage in Pakistan?

If caused by manufacturing cell defects, yes. However, if caused by uncleaned bird droppings or external physical damage, manufacturers will reject warranty claims.