EN3RGY SOLUTIONS
Why You Should Check Your Solar System After an Adelaide Heatwave
Adelaide is no stranger to extreme temperatures, but a prolonged heatwave puts an immense amount of strain on your solar energy system. When the ambient air temperature hits 35°C, the reflected heat from a dark rooftop can soar to 60°C or higher.
Just as the human body suffers from heat exhaustion and hyperthermia in these conditions, solar panels face their own version of “heat stress.” Understanding how your system reacts to extreme heat is vital for ensuring its long-term safety and performance.
How Heat Impacts Solar Efficiency
It is a common misconception that solar panels work better the hotter they get. In reality, solar panels thrive on sunlight (photons), not heat. Most solar panels are tested at a standard temperature of 25°C. For every degree the panel temperature rises above this point, its efficiency drops.
This loss is measured by the Temperature Coefficient.
- Standard Performance: Most panels lose between 0.3% and 0.5% of their power output for every degree above 25°C.
- The “Roof Effect”: Because panels are dark and catch reflected heat from the roof, they can easily reach 65°C on a typical Adelaide summer day. This can result in a temporary power loss of 20% or more during the hottest part of the day.
Older Systems vs. New Technology
Older solar systems are particularly vulnerable to permanent damage during heatwaves. Extreme heat can expose underlying weaknesses, such as:
- Micro-cracks: Rapid expansion and contraction (thermal cycling) can cause tiny cracks in the silicon cells.
- Hotspots: If a single cell fails or is shaded, it can become incredibly hot, potentially melting the backsheet of the panel.
- Inverter Stress: Your inverter is the “brain” of the system and contains sensitive electronics. Extreme heat can cause it to “derate” (limit its output) or shut down entirely to prevent internal damage.
Post-Heatwave Checklist
Once the temperatures drop, it is important to verify that your system has returned to normal operation.
- Check the Inverter Display: Look for any red warning lights or error codes. Common codes like “Over Temperature” or “Isolation Fault” often appear after heat stress.
- Monitor Your Apps: If you have Wi-Fi monitoring, examine your production logs. Look for any unusual “dips” in production that don’t align with cloud cover.
- Visual Inspection: From the ground, check for any visible signs of browning or discolouration on the panels.
FAQ
Most modern inverters will “derate,” meaning they automatically lower their power output to reduce internal heat. If the temperature exceeds a safety threshold (usually around 85°C internally), the inverter may shut down completely to prevent a fire or permanent circuit damage.
This is due to the temperature coefficient. While there is plenty of sunlight, the extreme heat increases electrical resistance in the silicon cells, which lowers the voltage and results in less total power being generated.
We do not recommend this. Spraying cold water on extremely hot glass can cause thermal shock, leading to the glass shattering or micro-cracks forming in the cells. It can also cause mineral scale (limescale) to build up on the panels, which reduces long-term efficiency.
Key signs include the inverter fan running constantly at high speed, “High Temperature” error codes, or a significant, unexplained drop in daily kWh production compared to previous weeks with similar sunlight.
