Troubleshooting · 29 guides
Low solar output
Each guide says what you will see, why it happens, what you can safely check yourself and when to call an engineer. Never open the DC side yourself: solar strings stay live whenever there is daylight.
Solar losses from dust, smog and monsoon
Pakistan’s dust, winter smog and monsoon storms all cut generation.
Low solar output at midday
A healthy system peaks between late morning and mid-afternoon.
Hot spots on solar panels
A hot spot is a patch of a panel that runs much hotter than the rest.
PID: slow solar panel power loss
Potential induced degradation (PID) is a gradual loss of panel output caused by voltage stress, heat and humidity.
Panel degradation or a real fault?
All panels lose a little output every year.
Solar panel junction box failures
The junction box on the back of each panel is where the cables leave the panel and where its bypass diodes sit.
Solar output drop in Lahore smog
Between November and January, smog and haze over Lahore reduce the sunlight reaching your panels.
White stains on panels after washing
Washing with hard tap water can leave white mineral spots on the glass.
Solar panels cracked by hail
Hail in Punjab this year cracked panels on homes and tubewells.
Solar structure check before storms
Storms in Lahore have torn loose rooftop panels, and authorities have urged owners to secure them.
Textile lint and dust on Faisalabad rooftops
In Faisalabad’s industrial areas, cotton lint and factory dust settle on panels all year, not only in the dry season.
Solar on sawtooth shed roofs
Many mills have sawtooth (north-light) roofs.
Solar housekeeping on textile rooftops
Solar equipment works best on a clean, clear roof.
Two inverters, different generation
Two inverters on one roof do not necessarily receive the same solar input or operate under the same conditions.
Panels not producing nameplate wattage
A panel’s wattage describes its output under specified test conditions.
Flat solar curve: clipping or a fault?
A production graph that rises in the morning and then forms a flat top can raise concerns.
One PV string or input shows zero
A zero reading on one solar input deserves context.
Solar output fell after adding panels
Adding panels should follow a review of the existing inverter and array design.
Little extra from bifacial panels
Bifacial panels can collect light from the front and rear, but the additional rear-side contribution depends on the installation.
Dark lines or snail trails on panels
Dark lines visible through a panel’s front surface can be worrying, especially when they appear some time after installation.
Solar panel bubbling, peeling or yellowing
A change in a panel’s appearance should be described carefully.
Birds nesting under solar panels
Bird activity under an array may first become noticeable through noise, feathers, nesting material or repeated droppings.
Panel microcracks from handling or roof work
A panel can look intact from a distance while questions remain about the condition of its cells.
Replacing a discontinued solar panel
When an original panel is no longer available, choosing a replacement involves more than finding the same wattage.
Checking a panel-cleaning contractor
A cleaning method should suit both the modules and the roof.
Output changed after a tank or wall went up
A new rooftop object or nearby structure can change the light reaching an existing solar array.
Inverter Not Taking Solar Power (PV Input Zero)
An inverter not taking solar power, with the PV reading at zero in daylight, means either no DC is reaching the inverter, or the inverter is refusing to use it.
One String Low Output: Why PV1 and PV2 Show Different Readings
One string low output is worth checking only when the two strings are built the same way: same number of panels, same panel model, same direction and tilt, and no shade.
Inverter Starting Late in Morning? Causes and Checks for On-Grid Systems
An inverter starting late in morning light is usually waiting for one of three things: enough panel voltage to pass its start voltage, a successful insulation test of the DC wiring, or a stable grid for the required check period.