07/03/2025
Regarding Cyclone Alfred -
Well we thought running out of toilet paper was the hot topic in an extreme event, but it seems deciding to turn your Solar PV system off or leave it on has taken the prize.
There have been concerns circulating about whether to turn off your solar PV system, which has understandably worried some people. However, it’s important to clarify how solar inverters work during power outages caused by storms or cyclones.
Solar inverters are designed to shut down automatically when there is a power loss. This prevents electricity from being fed into the grid, which could be dangerous if power lines are damaged. When power is restored, solar inverters will automatically turn on after going through a start up process, checking parameters such as grid voltage, solar output and safety protocols amongst many other parameters. Whether your inverter has automatically turned off or you have physically turned it off, the solar panel array, although not producing energy, is never safe to be interacting with if you are not a solar electrician.
The advice to turn your Solar PV off could be a cautious approach to allow less solar on the grid at times of grid instability.
In most cases, you do not need to turn off your system manually unless you suspect damage to your solar array cables or inverter, or if there is a risk of flooding. Solar inverters typically detect issues with the system and display a fault warning, often indicated by a red or amber light. If this happens, it’s a good idea to turn off your inverter and have it inspected by a solar electrician.
If damage has occured that has comprised the Solar PV system, generally inverters won't start up and you'll see a red or amber light on the inverter or a fault code on the inverter screen. If you saw this and it was safe to do so, you would follow the shutdown procedure label on the inverter and turn it off.
Another common characteristic, which is helpful to know, is that if you have sustained damage to solar DC cables and there is moisture present, it generally causes a fault alert on your inverter. This is common for those who have experienced a possum chewing through the insulation of a solar DC cable and it alerts a fault whenever it rains or after morning heavy dew.
We are naturally going to be experiencing a lot of wind and rain over the next few days and if you've chosen to turn your system off, you'll then be deciding when to turn it back on and if it is safe to do so. As with any electrical appliance, you'll first visually look over your system where possible to see if anything is damaged. By turning on your system and observing when it's wet and not producing much power, your inverter generally may detect a fault if your cabling has been damaged. Again, if this is the case you would follow the shutdown procedure label on the inverter and turn it off and have it inspected by a solar electrician.
Based on hail storm experience, solar panels can shatter from impact, but still produce power and inverters may not detect this. Shattered panels visually look a little different compared to others on your roof and although still producing energy, should be replaced or isolated when able to.
If you decide to turn off your system, follow the shutdown procedure labeled on your inverter:
First, turn off the Inverter AC Solar Main Switch, usually located in your switchboard.
Then, turn off the DC switch, which is located on or near the inverter.
If your solar inverter is at risk of flooding, it is strongly advisable to turn it off, just as you would with any other electrical device.
After the storm has passed, if there is no visible damage to your rooftop array, cabling, or inverter, you can turn the system back on in reverse order:
Turn on the Solar DC switch.
Turn on the Solar AC Main Switch.
When restarting your system, check that the inverter is powered on and that no fault lights are displayed. While inverter designs vary, a green light generally indicates normal operation, whereas a red or amber light signals a fault that requires professional inspection by a solar electrician.
Additionally, if your solar monitoring app shows your system as offline, it does not necessarily mean it is off. Many modern systems are connected to the internet via Wi-Fi or other methods, and an offline status could simply indicate a Wi-Fi connection issue. To confirm that your solar inverter is operating, always check the physical inverter itself.
Stay safe and take care.
from Local Power team
