Quick Summary
Installing solar is a significant investment, but once the system runs, it's easy to forget about it. The panels sit quietly on the roof, the inverter stays out of sight, and most homeowners only think about their system when the electricity bill arrives.
A solar system can operate while producing less electricity than it should. An inverter fault, new shading, damaged wiring, panel degradation, or a monitoring issue may reduce output without shutting the system down.
So, how do you know whether your solar system is working properly? Checking your inverter, reviewing the monitoring app, and comparing production over time can help you identify problems before you lose months of potential savings. This guide explains how to check your solar system’s performance, how much electricity it should produce, and warning signs that may need professional assessment.
How to Check Your Solar System’s Performance
A solar system does not need to stop working completely to cost you money. Even a partial reduction in generation increases the electricity you buy from the grid. Without monitoring, underperformance may go unnoticed for these reasons:
- The household still has electricity
- The system continues generating some solar power
- There may be no visible damage
- Electricity bills fluctuate between seasons
- Higher household usage can disguise falling solar production
- Some inverter and system faults do not cause a complete shutdown
Regular performance checks confirm your system is generating electricity, identify sudden changes, and show whether it delivers the value you expected.
Monitoring can help you:
- Check real-time solar generation
- Compare daily, monthly and annual production
- Identify inverter errors and system interruptions
- Detect unexpected declines in output
- Track grid imports and solar exports
- Understand how much solar your household uses directly
- Monitor battery charging and discharging
- Recognise when professional testing may be required
How Do I Know If My Solar Panels Are Working?
The easiest way to check if your solar panels are working is to review your inverter or solar monitoring app during the day. Your system should generally show that it is generating power when there is sufficient sunlight. Depending on your equipment, you may see:
- Current power production in kilowatts
- Electricity generated that day in kilowatt-hours
- System operating status
- Grid imports and exports
- Household electricity consumption
- Battery charge level
- Fault notifications or error codes
One lower-production day does not necessarily mean something is wrong. Cloud cover, rain, seasonal conditions, and high panel temperatures affect output. What matters is if production is consistently lower than expected under similar conditions. If the inverter shows no generation on a clear day, displays a warning light, or reports an error code, have a professional assess the system.
How Much Power Should My Solar System Produce?
No single production figure applies to every Australian solar system. Output depends on:
- System size
- Location
- Season
- Weather
- Roof orientation and pitch
- Shading
- Panel efficiency
- Inverter capacity
- Export restrictions
- System age
- Installation quality
As a broad guide, one kilowatt of rooftop solar generates about 3.5 to 5 kilowatt-hours of electricity per day on average across the year. Actual results vary considerably by location and season.
Based on that broad range:
- A 6.6kW system may average approximately 23 to 33kWh per day
- A 10kW system may average approximately 35 to 50kWh per day
- A 13kW system may average approximately 45 to 65kWh per day
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These are indicative annualised ranges, not daily guarantees. Production may be much higher on a clear summer day and much lower during winter or poor weather. Your original system design or proposal should include an estimated annual yield. This forecast is a better benchmark than a general national average because it accounts for your location, roof layout, panel orientation, shading, and equipment.
Five Ways to Check Your Solar System’s Performance
1. Check the Inverter
Your inverter converts direct current from the panels into electricity your home can use. It is one of the first places to check when assessing system health.
During daylight hours, check whether the inverter:
- Is switched on
- Shows normal operating status
- Displays current solar generation
- Has warning lights or error messages
- Is unusually noisy or repeatedly restarting
Indicator lights vary by brand. Consult the manufacturer’s instructions before interpreting any light or code. Do not open or attempt repairs on the inverter yourself.
2. Open the Solar Monitoring App
Most modern inverters include a monitoring platform that displays system information through an app or online dashboard.
Depending on the equipment installed, monitoring may show:
- Live solar production
- Daily, monthly and annual generation
- Household consumption
- Electricity imported from the grid
- Solar exported to the grid
- Battery charging and discharging
- Historical performance
- System errors and alerts
Common inverter and battery monitoring platforms include those provided by GoodWe, Sigenergy, Sungrow, Sofar and ESY Sunhome. If the app stops receiving data, it may be a communication problem rather than a solar fault. Investigate it, since a disconnected monitoring platform can hide real performance issues. A single day rarely provides enough information to judge system performance. Compare results over:
- Similar sunny days
- Consecutive weeks
- The same month in previous years
- Comparable seasons
- Periods before and after a noticeable bill increase
Solar production changes throughout the year. Comparing a winter month with a summer month does not give meaningful results. Year-on-year comparisons are more useful when weather and household conditions are similar. A gradual reduction is normal as panels age. A sudden or large decline is more concerning than a small change over years.
Your solar proposal should include an estimate of expected annual production. Compare the energy generated over the previous 12 months with that forecast. A modest difference may be due to weather, shading, or other conditions. Investigate a significant, sustained shortfall, especially if the system reports faults or produces less than before.
The estimated output in a sales proposal is not a guarantee, but it provides a useful starting point to determine whether the system operates within a reasonable range.
5. Review Your Electricity Bill
Your electricity bill can provide useful clues but does not measure solar performance on its own. Check for changes in:
- Electricity imported from the grid
- Solar exported to the grid
- Feed-in tariff credits
- Total household consumption
- Daily supply charges
- Electricity rates
- Billing period length
A higher bill does not automatically mean your solar system is faulty. Your system may generate normally while the household uses more electricity at night, runs more appliances, or has a lower feed-in tariff. If production appears normal but your bill remains high, read our guide to why your solar system may not be saving you money.
Signs Your Solar System May Be Underperforming
Warning signs include:
- Solar production has fallen suddenly
- The inverter displays an error or warning
- The monitoring app shows no generation during daylight
- Production is consistently lower than comparable periods
- Electricity imports have increased without a clear reason
- Solar export credits have dropped unexpectedly
- The inverter repeatedly shuts down or restarts
- The battery no longer charges or discharges normally
- Monitoring data has stopped updating
- Your system is producing well below its original forecast
- Part of the system appears to work while overall output remains unusually low
Some problems are caused by monitoring or internet connectivity rather than the solar equipment. A professional assessment can determine if the issue relates to data communication, system design, or an electrical fault.
Common Causes of Solar Underperformance
New or Increased Shading
Trees grow, neighbouring buildings are constructed, and roof-mounted equipment can create new shade. Even if the roof was unshaded when the panels were installed, surrounding conditions may change. The impact depends on the time of day, affected panels and system configuration.
Dirt, Debris and Animal Activity
Dust, leaves, bird droppings, and other debris can reduce sunlight reaching the panels. Accumulated material has a greater impact when it covers part of a panel or remains in place for long periods.
Birds and other animals can also nest beneath panels or damage exposed components.
Homeowners should not climb onto the roof to inspect or clean panels. Roof work presents serious fall and electrical risks and should be done by qualified professionals.
Inverter Faults
The inverter is a critical component and can experience faults, communication failures, overheating, or shutdowns. Some faults stop generation completely; others cause intermittent or reduced production. Record error codes and provide them to a licensed solar professional.
Wiring, Isolator or Connection Problems
Loose connections, damaged wiring, and degraded electrical components can affect output and create safety risks. These problems may not be visible from the ground and should be inspected only by a licensed electrician.
Panel Damage or Degradation
Solar panels gradually lose a small amount of capacity as they age. However, physical damage, moisture ingress, or component failure can cause a larger reduction. A qualified technician can test the panels and electrical strings to determine whether one part of the array is affecting overall production.
Export Limiting and Inverter Clipping
Some systems are restricted in how much electricity they can export to the grid. Larger panel arrays may generate more direct-current power than the inverter can convert at times. This doesn’t necessarily mean the system is faulty. Export limits and inverter sizing may be part of the approved design. Your installer can explain whether the behaviour shown in the monitoring data is normal for your configuration.
Changes in Household Electricity Use
Sometimes the solar system works correctly, but the home consumes more energy.
This may happen after installing or increasing the use of:
- Air conditioning
- Pool pumps
- Electric hot water
- Heating
- A second refrigerator or freezer
- Home office equipment
- An electric vehicle charger
- Additional household appliances
Monitoring household consumption alongside solar generation helps distinguish production issues from increased electricity use.
Why Peak Inverter Output Does Not Tell the Whole Story
Homeowners sometimes expect a 10kW solar system to continuously produce exactly 10kW. In practice, systems may not reach full capacity every day.
Output is affected by:
- Sunlight intensity
- Panel temperature
- Roof orientation
- Panel angle
- Shading
- System losses
- Inverter capacity
- Export controls
A cool, clear day may produce a higher peak than a hot day because solar panels become less efficient as temperature rises. Instead of judging the system by one peak figure, examine total daily and annual generation, performance trends, and results under similar conditions.
How Monitoring Can Improve Solar Savings
Monitoring does more than identify faults. It also shows when your household uses electricity and how effectively it uses solar power. Monitoring data shows that most solar electricity is exported while the household imports heavily at night; you may improve self-consumption by shifting flexible appliance use to daylight hours. Depending on your household, this may include running:
- Washing machines
- Dishwashers
- Pool pumps
- Electric hot-water systems
- EV chargers
- Heating or cooling
If changing usage times isn't practical, monitoring data can help determine whether battery storage is beneficial. Size a battery around actual generation and consumption patterns rather than selecting it based on a standard package or estimate.
A Simple Solar Performance Checklist
Use this checklist every few months:
- Is the inverter showing normal operation?
- Is the monitoring app receiving current data?
- Is the system generating during daylight hours?
- Are there any warning lights or error codes?
- Is daily production consistent with similar weather conditions?
- Has output changed substantially from the same period last year?
- Are grid imports unusually high during daylight hours?
- Have solar exports dropped unexpectedly?
- Is the battery charging and discharging normally?
- Has household electricity use recently increased?
- Is annual generation reasonably consistent with the original forecast? Regular checks make it easier to spot unusual behaviour before it affects your electricity costs.
When Should You Call a Solar Professional?
Arrange a professional assessment if:
- The inverter displays a persistent fault
- Solar production stops during daylight hours
- Generation drops suddenly without an obvious weather-related cause
- The monitoring platform repeatedly disconnects
- Output remains substantially below forecast
- The battery is not operating as expected
- You notice damaged or exposed components
- Electricity imports rise significantly while household usage remains similar
- You are unsure whether the system is operating safely
Do not attempt to open the inverter, disconnect panels, inspect rooftop wiring, or repair electrical components yourself. Solar equipment can remain electrically live even when parts of the system appear switched off.
Your Solar System Is Delivering What It Should
A solar system should not be installed and then ignored for 20 years. Checking its performance helps protect your investment, identify faults, and confirm the system produces the electricity it was designed to generate. Start by checking your inverter and opening the monitoring app. Compare production across similar periods, review your electricity bill, and watch for sudden or unexplained changes.
If something doesn't look right, Stag Electrical can assess your system, identify the cause of underperformance, and explain what is required to restore safe, reliable operation.
Book a professional solar system assessment to check whether your system is operating correctly and delivering the performance you should expect.
Frequently Asked Questions About Solar System Performance
How Do I Know If My Solar System Is Working Properly?
Check your inverter or monitoring app during daylight hours. It should show current solar generation without persistent warnings or error codes. Compare production with similar days, previous months, and the same season in past years. A sudden or sustained drop may indicate underperformance.
How Much Electricity Should My Solar System Produce Each Day?
On average, one kilowatt of rooftop solar generates 3.5 to 5 kilowatt-hours of electricity per day in Australia. A 6.6kW system averages 23 to 33kWh daily, while a 10kW system averages 35 to 50kWh. Actual production depends on location, season, weather, shading, roof orientation, and system design.
Why Is My Solar System Producing Less Power Than Expected?
Lower production results from cloudy weather, seasonal changes, shading, dirt, high panel temperatures, inverter faults, damaged components, or degraded electrical connections. Export limits and inverter settings also affect the output shown in your monitoring app.
Should My Solar System Reach Its Full Rated Capacity?
Not necessarily. A 10kW system does not continuously generate exactly 10kW. Panel temperature, sunlight intensity, roof orientation, shading, inverter capacity, and system losses affect peak output. Total daily and annual generation offer a more reliable performance measure than a single momentary reading.
Does a High Electricity Bill Mean My Solar System Is Not Working?
Not always. Your system may work correctly while your household uses more electricity, consumes most power after sunset, or receives a lower feed-in tariff. Compare solar generation, grid imports, exports, and household consumption before assuming a system fault.
Why Has My Solar Monitoring App Stopped Updating?
The app might have lost its internet or Wi-Fi connection even though the solar system is still generating. Check if the inverter operates normally and restart the approved communication equipment per the manufacturer’s instructions. If monitoring stays disconnected or the inverter shows an error, contact a solar professional.
What Are the Warning Signs of an Underperforming Solar System?
Common warning signs include sudden production decline, persistent inverter errors, no generation during daylight, unusually high grid imports, falling export credits, interrupted monitoring data, or a battery that no longer charges and discharges normally.
How Often Should I Check My Solar System’s Performance?
Check the monitoring app at least once a month and review longer-term production every few months. Also check after severe weather, an unexpected electricity bill, or noticeable changes in household energy use.
When Should I Have My Solar System Professionally Inspected?
Arrange an assessment if the inverter reports a persistent fault, production stops or falls suddenly, annual generation is substantially below expectations, monitoring repeatedly disconnects, or visible components appear damaged. Only appropriately qualified professionals should inspect electrical and rooftop components.
Can I Check or Repair My Solar Panels Myself?
You can safely review the inverter display, monitoring app, and electricity bills from ground level. Do not climb onto the roof, open the inverter, disconnect panels, or attempt electrical repairs. Solar equipment can remain live even when the system appears switched off.
How Can Solar Monitoring Help Reduce My Electricity Bill?
Monitoring shows when your system generates electricity and when your household imports power from the grid. You can increase savings by running flexible appliances during solar production hours, addressing underperformance, or determining whether a battery suits your actual usage pattern.
Do Solar Panels Produce Less Electricity as They Age?
Yes. Solar panels generally degrade gradually over their operating life. A small long-term decline is normal, but a sudden or substantial reduction may indicate shading, damage, an inverter problem or another system fault that requires investigation.
