When your home solar panels are not producing the power you expect, it can feel alarming. In many cases, the cause is a normal variation in sunlight or a minor issue you can identify safely from the ground. This guide walks you through the most common reasons for low solar production and the steps you can take before calling a professional. It draws on advice from the U.S. Department of Energy, the U.S. Energy Information Administration, and the Queensland Government’s solar maintenance resources (Australian guidance that reflects universal safety principles).

Safety first: Never attempt to repair electrical issues yourself. The Queensland Government’s solar maintenance guide stresses that all inspections should be done from the ground, and only a licensed electrician or accredited installer should perform close-quarters checks or go onto the roof.

Rule out normal causes of low solar output

Solar panels produce electricity only when sunlight hits them. According to the U.S. Energy Information Administration, PV cells generate the most electricity when they are directly facing the sun. That means output naturally changes with the time of day, the season, and the weather. A cloudy afternoon will always yield less power than a clear summer noon. Before assuming a fault, compare your current production to what you would expect for the conditions.

The U.S. Department of Energy’s Homeowner’s Guide to Going Solar notes that trees near your home can create excessive shade on your roof, reducing panel output. The Department of Energy’s design basics article explains that microinverters, which are attached to each individual module, allow each panel to operate independently. The DOE says this is useful if some modules might be shaded. If output drops at the same time each day, look for a new source of shade.

Check your monitoring and electricity bills

The Queensland Government’s household solar maintenance guide recommends keeping an eye on your system’s performance by reviewing your electricity bills for drastic changes in generation or your solar feed-in credit. A sudden, sustained drop that does not match weather patterns could signal a problem. You should also check any monitoring data provided by your installer. Many systems come with an online portal or smartphone app that shows real-time and historical production. If you see a persistent decrease, it is worth investigating further. For more on interpreting alerts, see our monitoring alerts guide.

Read your inverter’s display and error lights

The same Queensland guide points out that the inverter is a key place to look for clues. During daylight hours, when the panels should be generating, check whether the inverter is showing a red or orange light. Many inverters also have a data screen or an online interface that displays error messages. Refer to your owner’s manual for the meaning of specific codes. If you see a warning light or an unfamiliar error, do not attempt to reset or repair the inverter yourself. Instead, note the message and contact your installer or a licensed electrician.

Inspect your system from the ground

A visual inspection from the ground can reveal several common problems. The Queensland maintenance guide lists what to look for:

  • Excessive build-up of hard-to-remove debris, such as tree sap or bird droppings, on the panels.
  • Panels that appear loose, not securely fastened, or visibly damaged.
  • Cracked or damaged cases on isolation switches or the inverter.
  • Wiring that looks frayed, damaged, or deteriorated.
  • Overhanging tree branches that may have grown since installation and are now casting shade.

If you spot any of these issues, or anything else that looks concerning, ask a qualified professional to inspect the system. The guide recommends that the inspector check that panels are clean, secure, and undamaged; vents are free of debris; switches are undamaged; wiring is intact; and emergency shutdown procedures are clearly displayed. For more on routine upkeep, visit our maintenance page.

If you have a battery, check its health and usage

If your solar installation includes a home battery, low overall output might be related to battery behavior rather than the panels themselves. The Queensland Government’s Battery Buyers Guide advises that you periodically check the unit for dirt, debris, and insect or animal infestation. It also warns against overusing the battery: fully charging and discharging it more than two to three times a day can shorten its lifespan. A home energy management system or companion app can help prevent excessive cycling. If your battery seems to be underperforming, first check the monitoring app for alerts. If something goes wrong, contact your installer. Should the installer be unavailable, reach out to the battery manufacturer directly, as product warranties are typically the manufacturer’s responsibility. For a deeper look at battery-related issues, see our battery problems guide.

Understand your inverter’s expected lifespan

Inverters are a critical component that convert the direct current (DC) from your panels into the alternating current (AC) your home uses. The U.S. Department of Energy’s Solar Photovoltaic System Design Basics article states that inverters are expected to be replaced at least once during the 25-year lifetime of a PV array. If your system is several years old and you notice a gradual decline in output that cannot be explained by shade or dirt, the inverter may be nearing the end of its service life. A professional can measure its performance and advise whether a replacement is needed. You can learn more about inverter types and their roles on our home inverters page.

Know when to call a professional

The Queensland maintenance guide emphasizes that when you have your system installed, the installer must provide instruction handbooks, warranty documents, and a maintenance schedule. Following that schedule and keeping records can help you catch problems early. If you notice any of the warning signs described above: persistent error lights, physical damage, or a sudden drop in generation that does not recover,it is time to call a licensed electrician or an installer accredited by a recognized body. Do not attempt to open the inverter, climb onto the roof, or handle wiring yourself.

Keep your original documentation, including model numbers and warranty terms, in a safe place. If the installer is no longer in business, the product manufacturer is the next contact for warranty questions.

Common symptoms and what to do about them

The table below summarizes typical symptoms of low solar production, possible normal causes, what you can check, and who should fix the issue if it persists.

Symptom Possible normal cause What to check Who fixes
Lower output on cloudy or rainy days Sunlight varies with weather Compare output to similar weather days in the past No fix needed; normal variation
Panels shaded by trees Tree growth since installation Inspect from ground for overhanging branches Homeowner (trim safely from ground) or arborist
Inverter shows red or orange light Fault or grid issue Read error message on display or app Licensed electrician or installer
Drastic drop in generation on bills System fault or monitoring error Check monitoring data, inverter lights Installer
Battery not holding expected charge Overuse or aging Review battery app for cycling patterns; avoid excessive full cycles Installer or manufacturer
Panels appear dirty or covered in debris Dust, bird droppings, sap Visual inspection from ground Professional cleaner (never climb onto roof yourself)

For a more detailed breakdown of production issues, see our production issues guide.

Frequently asked questions

Why are my solar panels not producing power even on sunny days?

Start with the checks you can make safely: the inverter display or app for error messages, and a look from the ground for new shade, damage or debris. The Queensland guide lists a red or orange inverter light during the day as a warning sign. Anything involving switches, breakers or wiring is a job for your installer or a licensed electrician.

How do I know if my inverter needs replacement?

The U.S. Department of Energy notes that they will likely need replacement at least once over a solar array’s 25-year life. Signs include frequent error codes, a persistent red or orange light, or a gradual decline in system output that cannot be explained by other factors. A qualified electrician can measure the inverter’s efficiency and confirm whether it is time for a new unit.

Can I clean my solar panels myself?

Follow the cleaning advice in your system’s manual, and do not go onto the roof. The Queensland guide says close-quarters inspections and anything that requires going onto the roof should be left to a qualified professional, and it lists clean panels among the items an inspector should check.

For more step-by-step troubleshooting advice, visit our Home Solar Troubleshooting hub.

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