The company Unleash Solar has gone into voluntary administration, a day after Consumer and Business Services issued a public warning about it.
Commissioner for Consumer Affairs Paul White said 17 customers had complained of faulty equipment and uncompleted warranty work.
He said he expected the number of complaints to rise significantly.
Meertens Chartered Accountants has been appointed voluntary administrator.
At its peak, Unleash Solar, based in Adelaide, had an annual turnover of about $80 million and employed about 80 people and 100 contractors.