Rooftop DC isolators and solar system fires

The role of rooftop DC isolators in solar system installations in Australia has been a focus of Alternative Technology Association (ATA) investigations and member discussions over the past few years.

In 2016 the ATA commissioned a group of students from the Worcester Polytechnic Institute (WPI) in Massachusetts, USA, to undertake a study into rooftop solar-related fires in Australia and internationally, part of which focused on the role of DC isolators and other system components.

The WPI students came up with a number of findings and recommendations based on research and consultations with the solar and firefighting industries. Of specific note:

  • Rooftop DC isolators and solar inverters were found to be the main causes in solar-related fires. From 2009 to 2015, between 38% and 50% of recorded solar-related fires in WA and NSW were caused by a DC isolator. Prior to 2015, the majority of solar-related fires in Queensland were associated with DC isolators.
  • The ATA should advocate for the removal of rooftop DC Isolators from the AS/NZ 5033 Standard.
  • Homeowners ought to be made aware of product recalls on solar system components – in particular the recalls on seven rooftop DC isolator products since 2014.

The WPI final report can be downloaded below. A fact sheet on the investigations surrounding DC isolators can be found in the final Appendix (G) in the report. An ATA summary and response to the students’ investigations into rooftop DC isolators can also be downloaded below.

The ATA will be engaging with the solar and firefighting industries, along with Standards Australia, over the future role of rooftop DC isolators in the Australian solar industry.

For more information contact Damien Moyse, the ATA’s policy and research manager.

Click here to read the WPI report on fire safety of solar systems.
Click here to read the ATA response on fire safety and DC isolators.