Output falling is the commonest thing customers call about, and in most cases the cause is one of four things you can check yourself in ten minutes.
1. Dust
In Peshawar this is the biggest avoidable loss by a distance. A film of dust you can barely see costs real generation, and a neglected array can lose around a tenth of its output. After a dust storm it can be worse.
What to do: rinse the panels with plain water every couple of months in dry weather, early morning or evening. Not in the middle of the day — cold water on hot glass is a bad idea. No detergent, no stiff brush, and never walk on the modules.
2. Shading
One shaded module can drag down the whole string it sits in, so a small shadow can cost far more than its size suggests.
Shadows move through the year. A tree that cleared the array in June may not in December, when the sun sits lower. A new wall, a water tank, a neighbour's extension or an aerial can all appear after the installation.
What to do: look at the array at nine in the morning, at noon and at three in the afternoon. If something is shading it that was not there before, that is your answer.
3. Heat
Panels produce slightly less as they get hotter. This is normal physics, not a fault, and it is why a clear day in April can out-produce a hotter one in June. Proper mounting leaves an air gap behind the modules for exactly this reason.
What to do: nothing. But do not be alarmed by lower midsummer figures than you expected.
4. Something has tripped
A breaker, an isolator or a surge protector may have operated. This is the system doing its job.
What to do: check the inverter display for a fault code. If there is one, switch off at the isolator, wait a minute, and switch back on. If it clears and stays clear, it was a transient. If it returns, call us and tell us the code — it saves a visit.
Seasonal and weather effects that are not faults
- Overcast days produce substantially less. That is expected.
- Short winter days mean fewer generating hours, so a lower daily total even when the system is perfect.
- Generation peaks between mid-morning and mid-afternoon and tapers at both ends.
Compare like with like: this January against last January, not January against June.
When to call us
- A fault code that returns after a restart.
- Output far below normal on a clear day with clean panels.
- Any smell of burning, discoloured cable or warm socket — switch off at the isolator and call immediately.
- A battery that will not hold through an evening it used to manage.
We service what we install, and we repair inverters at board level on all the major brands including ones we did not supply. Warranty claims go through us rather than you chasing the manufacturer.
If you are still planning a system, the load calculator sizes it from the appliances you actually own.