It's a fantastic feeling to see your electricity meter slowing down or even spinning backwards thanks to your solar system. But what happens when that reliable hum of energy generation starts to falter? When your solar panels aren't generating enough power, it can be frustrating, especially with load shedding being a persistent concern in South Africa. We've spoken to numerous experienced solar installers and technicians across the country, and they often encounter a handful of common issues that can cause a solar system to underperform.

This guide will walk you through some of the most frequent culprits behind a sluggish solar system and provide practical maintenance checks you can perform. Understanding these issues will not only help you troubleshoot effectively but also know when it's time to call in the professionals.

Why Your Solar System Might Be Underperforming

Before diving into specific troubleshooting steps, it's helpful to understand the various components of your solar system and how they work together. Your panels convert sunlight into DC electricity, which then flows to an inverter that converts it into AC electricity for your home. If you have a battery, it stores excess energy. Any disruption in this chain can affect performance.

Dirty Solar Panels: The Obvious Culprit

It might seem too simple, but accumulated dirt, dust, bird droppings, or even leaves can significantly reduce your solar panel's efficiency. Think about it: if sunlight can't reach the photovoltaic cells, they can't convert it into electricity. This is especially true in areas of South Africa with high dust levels or where strong winds kick up a lot of debris.

• Expert Insight: "We often get calls from homeowners convinced they have a major inverter fault, only to find the panels are so encrusted they're barely letting any light through," shared a seasoned solar technician from Durban. "A good clean can sometimes boost output by 10-15% instantly."

Inverter Errors: The Brains of Your System Acting Up

The inverter is the heart of your solar system, converting the DC power from your panels into usable AC power for your home. When your inverter displays an error code, it's a clear signal that something isn't right. These errors can range from minor glitches to significant component failures. Common inverter issues include:

• Grid Faults: The inverter might detect an issue with the grid connection, causing it to shut down for safety.
• Overvoltage/Undervoltage: If the voltage from the panels or the grid is outside the inverter's operating range, it will stop functioning.
• Isolation Faults: This indicates a leakage of current, often due to damaged wiring or insulation. It's a critical safety concern.
• Communication Errors: The inverter might not be communicating correctly with other system components, like optimisers or monitoring systems.
• Internal Component Failure: Like any electronic device, internal components can fail over time, leading to a complete shutdown or reduced performance.
• Expert Insight: "One time, a client in Pretoria called about their system constantly tripping," recounted a solar installer. "Turned out, their inverter was displaying an 'isolation fault' error. We traced it back to a section of wiring that had been chewed through by rats – a real fire hazard! It just goes to show how critical those error codes are."

Wiring Issues: Loose Connections and Damaged Cables

Just like the wiring in your home, your solar system's electrical connections need to be secure and intact. Loose connections, corroded terminals, or damaged cables can lead to resistance, power loss, or even complete system failure. This can be caused by environmental factors, poor installation, or even pests.

Battery Degradation or Faults: If You're Storing Power

For those with battery backup systems, battery performance is crucial. Over time, batteries naturally degrade, losing their capacity to store and discharge energy efficiently. However, outright battery faults can also occur due to manufacturing defects, incorrect charging parameters, or extreme temperatures. If your battery isn't holding a charge or discharging properly, it will severely impact your system's ability to provide power when the sun isn't shining.

Shading: A Persistent Problem

Even partial shading on your solar panels can drastically reduce their output. This is because panels are typically wired in series, and if one cell or panel is shaded, it can act like a bottleneck, limiting the current for the entire string. Shading can come from trees that have grown, new structures, or even accumulated debris.

• Expert Insight: "We had a client in the Western Cape whose system performance dropped significantly during winter," an installer explained. "After a site visit, we realised a large tree on a neighbouring property, which wasn't an issue in summer, was casting a shadow across a good portion of their array during the shorter winter days. Sometimes, it's about observing your system's environment throughout the year."

Your DIY Maintenance Checklist: What You Can Do

While some issues require professional intervention, there are several checks you can safely perform yourself to identify and potentially resolve minor problems.

Disclaimer: Always prioritise your safety. Working with electricity can be dangerous. If you are unsure about any step or feel uncomfortable, do not attempt it yourself. Contact a qualified solar professional.

• • Visual Inspection of Panels:Look for any obvious dirt, dust, leaves, or bird droppings on the surface of your panels.
  • Check for any physical damage like cracks, chips, or discolouration.
  • Observe if any new structures or vegetation are casting shadows on your panels throughout the day.
  • Panel Cleaning:If your panels are dirty, a simple clean can make a world of difference.
  • Method: Use a soft brush or cloth and plain water. Avoid harsh detergents or abrasive materials, which can damage the panel surface.
  • Timing: Clean in the early morning or late afternoon when the panels are cool to avoid thermal shock.
  • Safety: If your panels are on a roof, do not attempt to clean them yourself unless you have appropriate safety equipment and experience working at heights. It is often safer and more effective to hire professionals for roof-mounted panel cleaning.
  • Check Inverter Display:Most inverters have a digital display that shows real-time performance data and error codes.
  • Note down any error messages or unusual readings. Refer to your inverter's user manual for the meaning of specific error codes. Many common errors can be resolved by simply restarting the inverter (following the manufacturer's instructions carefully).
  • Is the inverter receiving power from the grid (if it's a grid-tied system)? Check if any circuit breakers related to the solar system have tripped in your main distribution board.
  • Listen for Unusual Noises:While not always indicative of a fault, any unusual buzzing, humming, or clicking sounds from your inverter or other components could signal an issue.
  • Examine the Area Around Your System:Look for any signs of pest activity (e.g., chewed wires).
  • Ensure proper ventilation around your inverter and batteries to prevent overheating.
  • Check that nothing is blocking the airflow to these components.

When to Call a Professional Solar Technician

While DIY checks can help, many solar system issues require the expertise, specialised tools, and safety certifications of a qualified professional. Here's when you should definitely reach out to an expert:

• Persistent Inverter Errors: If your inverter continuously displays error codes even after you've tried simple resets, it's a clear sign that a deeper issue needs investigation. An "isolation fault" error, in particular, should never be ignored as it poses a safety risk.
• Significant Drop in Performance Without Obvious Cause: If your system's output has dropped dramatically and cleaning or shading isn't the issue, there could be a problem with the panels themselves, the wiring, or internal inverter components.
• Damaged Wiring or Components: Never attempt to repair damaged electrical wiring or internal solar components yourself. This is highly dangerous and requires a certified electrician or solar technician.
• Battery Issues: If your batteries aren't charging, discharging, or holding a charge as expected, or if you notice any physical swelling or leaks, contact a professional. Batteries can be volatile, and improper handling can be hazardous.
• Safety Concerns: Any sparks, smoke, burning smells, or unusual noises that make you feel unsafe should prompt an immediate call to an emergency electrician or solar technician.

A skilled solar technician will be able to perform diagnostic tests, identify the root cause of the problem, and carry out safe and effective repairs, ensuring your solar system gets back to generating clean, efficient power for your home.

FAQs About Solar System Performance

How often should I clean my solar panels?
The frequency of cleaning depends on your location and environmental factors. In dusty areas or where bird activity is high, you might need to clean them every 3-6 months. In cleaner environments, once or twice a year might suffice. Observe your panels; if they look visibly dirty, it's probably time for a clean.

Can load shedding damage my solar system?
Modern solar systems designed for South African conditions are generally built to handle load shedding. Grid-tied inverters will shut down when the grid goes down (for safety reasons, to prevent back-feeding the grid). Hybrid or off-grid systems with batteries are designed to seamlessly switch over. However, frequent power surges or fluctuations, especially when power returns, can potentially stress components over time. It's always a good idea to ensure your system has appropriate surge protection.

What is the typical lifespan of solar panels and inverters?
Solar panels are incredibly durable and typically come with performance warranties of 20-25 years, meaning they are guaranteed to produce a certain percentage of their original output after that time. Inverters, being electronic devices with more moving parts, generally have a shorter lifespan, typically 5-15 years, depending on the type and quality. Batteries for home use usually last 5-15 years, depending on the technology and how they are used.

Is it normal for my solar output to drop in winter?
Yes, it is perfectly normal for your solar system's output to decrease during winter months in South Africa. This is due to several factors: shorter daylight hours, lower sun angles (meaning less direct sunlight), and potentially more cloudy or rainy days. While cooler temperatures can actually improve panel efficiency slightly, the reduced sunlight hours are the dominant factor. Your system will naturally produce less energy in winter than in summer.