July 22, 2025

Your Solar System Isn't Performing? Here's What to Check First

A well-performing solar system is essential for maximizing your long-term energy savings. But when performance starts to dip, or electricity bills stay stubbornly high, it's time to investigate.

In this blog, we'll walk you through how to diagnose issues with your system, what benchmarks to expect, and how to get things back on track. We'll cover everything with a friendly, expert touch.

1. Why Solar System Performance Matters

Your solar system is an investment in both your home and the planet. Solar system performance determines how much of your energy needs are covered by clean power.

Tracking performance not only ensures you're saving money but also helps you spot issues before they escalate. Regular monitoring prevents small problems from turning into costly repairs or bigger inefficiencies.

2. Common Signs of a Poorly Performing Solar System

Infographic showing four signs of poor solar system performance: sudden drop in solar output, solar hotspots, high electricity bills despite solar, and inverter warning lights or errors

Is your system not pulling its weight? Be on the lookout for these warning signs:

Sudden drop in solar output – A noticeable drop in generation is often the first clue.
Solar hotspots – Discolored or cracked cells may indicate overheating, causing solar hot spot
High electricity bills despite solar – If your grid usage isn't dropping, something's wrong.
Inverter warning lights or errors – Alerts and error codes mean it's time for a check-up.

3. What to Check First When Your Solar Isn't Performing

Checklist image from Solar Junction showing six things to check if your solar system isn’t performing: inverter status, shading issues, dirt on panels, tilt angle, wiring faults, and age-related degradation.

3.1 Check the Inverter

The inverter is your system's brain. If it's offline or showing errors (solar panel inverter not working), your panels may not be feeding any energy. Always inspect status indicators and error codes first.

3.2 Look for New Shading

New nearby growth, scaffoldings, or rooftop obstructions can block sunlight. Shading significantly reduces solar system performance, especially during morning or afternoon peaks.

3.3 Cleanliness Matters

Dust, bird droppings, and leaves reduce output. Gently clean panels or hire a professional and just make sure it's done safely and without abrasive chemicals.

3.4 Assess Tilt and Orientation

Even small changes to pitch or direction can impact performance. The effect of tilt angle on solar panel output is often overlooked. Ensure panels are oriented to the sun's path across the year.

3.5 Inspect Wiring and Connections

Brittle or loose wiring and corroded connectors can introduce resistance, slashing system efficiency. If you suspect this, get a licensed electrician to inspect it.

3.6 Account for Age-Related Degradation

Panels lose efficiency with age; that's natural solar panel efficiency over time. Typical degradation is around 0.5–1% per year, so a 10-year-old system may be operating at 90–95% of its original capacity.

4. Expected Output Benchmarks (by System Size)

Use these guidelines to assess whether your system is underperforming:

6kW solar system daily output ~ 24–27 kWh/day
10kW solar system daily output ~ 38–44 kWh/day
13kW solar system daily output ~ 50–55 kWh/day

If your current numbers fall well below these figures, it's time for a deeper dive.

5. How to Maintain Peak Solar System Performance

Infographic listing 4 tips to maintain peak solar system performance: use inverter apps, schedule inspections, clean panels regularly, and reassess tilt and orientation.

Monitoring tools & apps – Mostly all inverters come with apps that track yield and flag issues.
Professional inspections – Annual maintenance checks can catch early signs of shading, wear, or hardware faults.
Cleaning tips – Clean panels in the morning or evening with soft water and gentle tools.
Tilt angle and orientation checks – Reassess panel angle seasonally and adjust as needed.

6. When to Consider a System Upgrade or Expansion

If your solar system is more than 8–10 years old and consistently underperforming despite maintenance, it may be time to consider a solar system upgrade. Modern panels offer significantly improved efficiency, and newer inverters come with advanced monitoring tools that help maximize solar system performance.

Additionally, if your household energy needs have increased, such as due to electric vehicle charging or a home extension, expanding your system might be more cost-effective than continuing with an underpowered setup.

7. The Role of Battery Storage in Boosting Performance

Another way to enhance your system’s output efficiency is by adding a solar battery. Even if your panels are generating well, without storage, excess energy sent back to the grid earns you less than what you pay to draw power at night.

By installing a solar battery for home use, you can store surplus energy for evening use, reduce grid reliance, and improve your return on investment.

If your system includes storage, low performance could also signal battery degradation, something worth checking during routine assessments.

Final Thoughts

Excellent solar system performance isn't just luck; it's the result of regular monitoring, maintenance, and care. If you notice a dip in output or suspect solar panel efficiency over time is declining, act promptly.

Need a professional inspection or help troubleshooting? Solar Junction offers expert diagnostics, maintenance, and post-install support to keep your solar system operating at its best.

Ready for a performance check? Contact Solar Junction today and reclaim your solar savings!