Why Is My Solar System Not Saving Me as Much as It Used To?
Your solar system may not be saving as much because the panels have….
- 24 Quay Street, Bundaberg QLD 4670
Matt Farrell Electrical – Electrician Bundaberg
Why Is My Solar System Not Saving Me as Much as It Used To?
Your solar system may not be saving as much because the panels have become less efficient, they are dirty or shaded, or there is an issue with the inverter or other equipment.
It does not necessarily mean your solar system has failed. In many cases, there is a simple reason behind the drop in savings and it can often be fixed.
So, what could be reducing your solar savings, and how can you tell what is going wrong? Let’s look at the most common causes and what you can do about them
Key Takeaways
- Solar panels naturally lose a bit of efficiency each year around 0.5% to 1% on average.
- Dirt, dust, bird droppings, and pollen can block sunlight and cut your output by 10% to 30% or more.
- Inverter issues are one of the biggest culprits, inverter faults account for about 37% of all solar power losses.
- Your energy usage might have changed because more people at home, new appliances, or an electric vehicle can eat up your solar savings.
- Shade from new trees or nearby buildings can slash your system's output.
- Feed-in tariffs have dropped a lot in recent years, so exporting power is not as profitable as it used to be.
- Warm outlets or switchboard. Heat means resistance. And resistance means trouble.
Why Are My Solar Panels Producing Less Power Than Before?
There are a handful of common reasons why a solar system starts underperforming. Let us run through them.
Dirty panels
This is the big one. Dust, pollen, bird droppings, and general grime build up on your panels over time. In Queensland, where we get dry spells and plenty of dust, this can be a real problem. Studies have shown that dust accumulation can reduce solar panel efficiency by anywhere from 5% to 25%, depending on the location and weather conditions. In some cases, dirty panels have been found to lose up to 30% of their output. A good clean can make a world of difference.
Natural degradation
Solar panels do not last forever. They degrade slowly over time. The average degradation rate for modern panels is around 0.5% to 1% per year. That means after ten years, your system might be producing 5% to 10% less power than when it was new. It is gradual, so you might not notice it day to day, but over a few years, the drop adds up.
Inverter problems
Your inverter is the brain of your solar system. If it is not working properly, your whole system suffers. Inverter faults alone account for about 37% of total observed power losses in solar systems. Inverters can degrade over time, especially in Queensland’s heat. Poor ventilation, overheating, and general wear can cause them to derate — meaning they produce less power than they should. If your inverter is more than ten years old, it might be time to think about a replacement.
Shade
Even a small amount of shade can cause big problems. A shadow covering just 5% of a solar panel can reduce its output by 30% to 50%. Trees grow, new buildings go up, and what was once a sunny roof can become a shaded one over time.
Faulty wiring or loose connections
Loose connections can reduce efficiency by 5% to 8% due to resistance buildup. Faulty wiring is responsible for 12% to 18% of all solar system failures. These are issues that a qualified electrician bundaberg can spot and fix during a routine check.
How Do I Know If My System Is Underperforming?
The best way to tell is to keep an eye on your monitoring app or inverter display. Most modern systems come with some kind of monitoring that shows you how much power you are generating.
Compare your current output to what it was at the same time of year a few years ago. If you are generating noticeably less power on a sunny day, something is probably wrong.
You can also check your electricity bills. If your bills are going up even though your usage habits have not changed much, your system is likely not pulling its weight.
What Should I Do If My Solar Savings Are Dropping?
Here are some practical steps you can take.
Check your panels. Have a look at them. Can you see dirt, dust, or bird droppings? If they look grubby, a clean might be in order. You can hose them down from the ground with a garden hose, but do not use high-pressure water or abrasive cleaners, they can damage the panels. For a proper job, especially if your roof is high or tricky to access, it is worth getting a professional in.
Check your inverter. Look at the display screen. Is it showing any error codes? Is the production number lower than you would expect on a sunny day? If something looks off, give a solar technician a call.
Check for shade. Walk around your property and look at your panels from different angles. Have any trees grown taller? Have any new structures gone up nearby? Even partial shade can knock your output down significantly.
Review your energy usage. Have you added any new appliances? Has your family grown? Are you working from home more often? If your energy usage has gone up, your solar system might not be big enough to cover it anymore.
Quick Look: Common Causes of Solar Performance Drop
What Is Happening | Why It Matters | What You Can Do |
Dirty panels | Dust and grime block sunlight, cutting output by 10-30% | Clean your panels or book a professional clean |
Natural degradation | Panels lose 0.5-1% efficiency per year | Acceptable, but worth monitoring over time |
Inverter issues | Faults cause around 37% of all power losses | Get your inverter checked by a professional |
Shade | Even 5% shade can cut output by 30-50% | Trim trees or consider panel relocation |
Faulty wiring | Loose connections reduce efficiency by 5-8% | Have a licensed electrician inspect your system |
Changed energy use | More appliances or people = more power needed | Consider upgrading your system size |
When Should I Call a Professional?
If you have checked the easy things like cleaning your panels and making sure nothing is shading them and your system is still not performing as it should, it is time to call in the experts.
A qualified solar technician can run a full diagnostic on your system. They can test your panels, check your inverter, inspect your wiring, and identify any faults that might be costing you money.
At Matt Farrell Electrical, we specialise in solar system installation Bundaberg and the surrounding areas. We supply and install only high-quality PV panels and inverters, built tough to withstand the harsh Queensland climate. But we do not just install systems, we also provide installation, repair, and maintenance services for a range of solar systems.
If your system is not saving you as much as it used to, we can help. Our experienced team will work with you to diagnose the problem and get your system back to peak performance.
Contact us today to book a service or inspection. We are here to help you get the most out of your solar investment.
Frequently Asked Questions
It depends on where you live. In dusty areas or places with lots of bird activity, every six months is a good idea. In cleaner areas, once a year might be enough. Keep an eye on them, if they look dirty, clean them.
Most inverters have a lifespan of around 10 to 15 years. After that, they start to lose efficiency and are more prone to faults. If your inverter is getting old, it might be time to think about a replacement.
Yes, you can hose them down from the ground. But if your roof is steep or high, it is safer to call a professional. Never use high-pressure water, abrasive cleaners, or harsh chemicals, they can damage the panels.
There are a few possible reasons: your system might be underperforming, your energy usage might have gone up, or feed-in tariffs might have dropped. It is worth getting a professional to check your system and see what is going on.
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