They had conducted 387 inspections by the end of September.
About 20 per cent of solar systems were found to be “sub-standard” while 4 per cent were deemed to be “unsafe”.
“The ones that had an overall finding of unsafe would have been subject to a shutdown by the inspector … and referred to the state regulator,” acting renewable energy regulator Christopher Branson said.
Mr Branson said 387 inspections were not enough to draw conclusions about whether specific installers were dodgy.
Roof-top solar panels could be unsafe because of water getting into the system or wires being exposed.
The federal government is funding the inspections after its earlier roof insulation scheme was linked to four deaths and more than 200 house fires.
Previously Nextbigfuture had calculated that solar rooftop has the risk for significant deaths because of the risk that roof installers can fall off of roofs Nextbigfuture had also indicated that there was the increased fire risk of having added electrical systems. 4% unsafe solar roofing installations shows a very large electrical fire risk increase.