PV Solar flood safety

16/01/11

Several important PV Solar flood safety alerts have been put out including:

Clean Energy Council bulletin via the ATA website (what to do with PV Solar before, during and after a flood)
Queensland Electrical Safety Office via the Qld Police Service facebook page
NSW Department of Fair Trading

The following photos of a damaged PV solar system were taken on 15 January 2011 at a home in Brisbane's inner south after the 12/13 January flood inundation.

From the mud on the equipment you can see the cables, inverter and switching (DC and AC breakers) were completely submerged in the floodwaters, and the PV system was left on when the home was evacuated. 

After the flood, even though the electricity grid had been turned off by Energex, it was daylight and the PV panels were still able to generate electricity.  Therefore these waterlogged cables, switches and inverter were still a potential safety hazard, so if you see something like this after floods please DO NOT TOUCH!!. 

An electrician, who was appropriately trained, with appropriate safety clothing and equipment, was able to safely switch off these breakers.  However that's not the end of the safety story, see below...

Even though the switching is now off, the DC cabling from the PV panels to the switches are still a potential safety hazard if it has been damaged, or is water logged, or there is cleaning/repair work being done in the ceiling cavity. 

The PV panel array on the roof needed to be isolated before this cabling could be considered safe.  As this system was installed in early 2008, it did not have a roof isolation fuse installed (many PV systems installed since then have roof isolation fuses, which are mandatory in Victoria, so covering the panels is not required to isolate the system).  Each string of panels therefore needed to be covered (in this case with garbage bags) to stop electricity generation and allow the isolation of the PV array from the DC cabling to the switching near the inverter.  If you are not trained to safely work at heights please DO NOT GO ON THE ROOF!

The meterbox and main switches were equally submerged and will need a licensed electrical contractor to make safe, repair and clean out, which will allow the electricity from the grid to be reconnected.

The PV array is now safe and ready for the home to be repaired after which the PV system will be reconnected to most probably a new inverter and switching.  The flood reached into the ceiling cavity cellulose insulation of the home with the PV system.  You can see the height of the flood by the line on the neighbouring home.