Why Is My Solar System Producing Less Power Than Expected?
Quick Answer
Reduced solar output can be caused by shading from new trees or structures, dirty or dusty panels, seasonal changes in sunlight, an ageing inverter, or a fault somewhere in the system. Some reduction is normal in winter months or on overcast days, but a sudden or sustained drop compared to your usual generation is worth investigating. Checking your monitoring app or inverter display is a good first step before calling an electrician.
What Could Be Causing the Problem?
- Shading from trees, new buildings, or antennas that has developed since installation
- Dust, dirt, bird droppings or debris accumulated on the panels
- Seasonal reduction in sunlight hours and angle, particularly through winter
- An ageing or faulty inverter no longer converting power as efficiently
- A fault with one or more panels, or a wiring/connection issue within the system
- Cloud cover or unusually overcast weather over a sustained period
What Can I Safely Check?
- Check your solar monitoring app (if you have one) to compare current generation with the same period last year
- Look at your panels from ground level for obvious shading, dirt or debris — without climbing onto the roof yourself
- Check your inverter display for any error codes or fault indicators
- Note whether the drop coincided with a specific event (storm, tree growth, nearby construction)
When Should I Call an Electrician?
- Generation has dropped noticeably compared to the same time last year, beyond normal seasonal variation
- Your inverter is displaying an error or fault code
- You suspect panel damage from a storm or falling debris
- You're not comfortable identifying the cause yourself
- The system has never been serviced or inspected since installation
What Will an Electrician Check?
- Test panel output and inverter performance against expected specifications
- Inspect for shading, panel damage, or soiling affecting generation
- Check wiring connections and inverter settings for faults
- Clean or recommend cleaning if soiling is a significant factor
- Provide a report on system performance and any recommended repairs
FAQs
Frequently asked questions
How much does solar output normally drop in winter?
Some seasonal reduction is expected due to shorter days and lower sun angle — the exact amount varies by system and location, which is why comparing to your own system's history is more useful than a general figure.
Do solar panels need regular cleaning in Perth?
Dust and pollen can accumulate over time, and periodic cleaning can help maintain performance, particularly in low-rainfall periods.
Can one faulty panel affect the whole system's output?
Depending on your system's configuration, a single faulty panel can sometimes affect the output of the group it's connected to — this is checked during an inspection.
How do I read my inverter's error codes?
Error code meanings vary by inverter brand and model — check your manual or contact an electrician if a code is displayed and you're unsure what it means.
Should I be monitoring my solar output regularly?
Keeping an eye on your generation via an app or inverter display helps you notice changes early, before a fault causes a significant loss in performance.
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