When you invest in solar panels, you expect a long-term return — clean energy, reduced bills, and peace of mind. But what happens when your solar system starts underperforming? The output drops, your savings shrink, and you’re left wondering: What went wrong?
In this guide, we explain exactly how to monitor performance drop-offs in solar systems, what signs to look for, how to identify the root cause, and what you can do to fix it — or prevent it altogether.
What Are Solar Performance Drop-Offs?
A solar performance drop-off refers to any unexpected reduction in the amount of energy your system is producing. This isn’t just about seasonal changes or cloudy days. We’re talking about a noticeable dip in daily or monthly energy output compared to previous performance or what your system is rated to deliver.
How to Monitor Your Solar System’s Performance
The earlier you detect a problem, the easier (and cheaper) it is to fix. Here’s how to keep an eye on your solar setup:
1. Use Your Solar Monitoring App
Most modern inverters come with built-in monitoring through a mobile or web-based app. These apps track:
- Daily, weekly, and monthly energy output
- Panel-level data (on some systems)
- System uptime and error alerts
Regularly checking this data can help you spot drop-offs early.
2. Compare Bills and Feed-in Credits
If your quarterly energy bill has increased — despite your usual energy usage — that’s a red flag. A drop in feed-in tariff credits (money you earn from exporting solar) can also indicate reduced output.
3. Check Inverter Display or Warnings
Your inverter is the brain of your solar system. Many display error codes or blinking lights when something goes wrong. If you see anything unusual:
- Write down the error code
- Check the inverter manual
- Contact your installer or a solar technician
Common Causes of Performance Drop-Offs
1. Shading or Dirt Buildup
Even partial shading from new trees, antennas, or bird droppings can reduce panel output. Dust, pollution, or sap on the panels can have the same effect.
Solution: Clean the panels once or twice a year (or more often if your area is dusty or near construction).
2. Inverter Malfunction
If your inverter is failing or turning off intermittently, your entire system’s output can be affected.
Solution: Get your inverter checked. Most have warranties between 5–10 years. A replacement might be covered.
3. Loose or Damaged Wiring
Rodents, poor-quality installations, or ageing systems can lead to wiring issues, which can significantly impact performance.
Solution: Only a licensed solar electrician should inspect or repair wiring issues.
4. Panel Degradation Over Time
All solar panels lose efficiency over the years, usually around 0.5% to 0.7% per year. However, if your system is only a few years old and performance has dropped sharply, it’s likely not just degradation.
Solution: Compare performance with your original installer’s expectations. If under warranty, you may be entitled to repairs or replacements.
5. Wi-Fi or Monitoring System Failures
Sometimes, the system is still producing energy, but the monitoring platform is offline, giving you misleading data.
Solution: Reset your Wi-Fi connection or speak to your system installer.
How Often Should You Monitor Performance?
You don’t need to check your app daily, but it’s a good idea to:
- Do a monthly review of your energy generation
- Track quarterly bills and feed-in credits
- Log your performance once every season
This habit can help you build a personal baseline and spot any early changes in output.
Should You Get a Professional Inspection?
If you’re noticing consistent drop-offs and can’t identify the reason, it’s wise to book a professional inspection. Experts can:
- Test the inverter and panel performance
- Run thermographic scans to detect faulty cells
- Check for shading, wiring or degradation issues
- Clean and reconfigure the system if needed
Pro tip: If your solar system is older than 5 years, an annual inspection is highly recommended.
How Sun Quotes Can Help You
If your system is underperforming and the original installer is unavailable, or you’re simply looking for a second opinion, Sun Quotes can help.
We’ll connect you with the top three local solar experts near you who can inspect, repair or upgrade your system — without wasting time calling around.
Final Tips to Avoid Solar Performance Drop-Offs
- Keep your panels clean and shaded
- Monitor energy output monthly
- Act quickly if the output seems unusual
- Get professional servicing every few years
- Choose quality components from the start
Get Expert Help Fast
If you’re experiencing a performance drop-off in your solar system, don’t wait. Get a quote from the top three solar retailers near you and save time with Sun Quotes. We’re here to help you get the most from your solar investment.
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