The target, revised down from 41TWh in 2015, has helped spur development of large-scale renewable energy projects, resulting in record years of investment, despite unsupportive federal administrations.
Roughly A$24 billion (US$16.2 billion) had been invested in the past 18 months alone, the CEC said.
Since the original RET of 41TWh was introduced in 2009, Australia's installed wind capacity has grown from 1.7GW to more than 5GW today.
"The RET has delivered dozens of wind and solar farms this decade, along with tens of thousands of jobs and tens of billions of dollars in project investment, which has created many new opportunities in the Australian economy," said CEC chief executive Kane Thornton.
Currently, there is no new system in place to bring new renewable projects to the market once the RET certificate-based scheme expires in 2020.
As with much of Europe, wind projects would not need much in the way of subsidy in Australia, but require revenue stability and policy consistency in order to attract the necessary investment.
"The industry doesn’t need new subsidies, we just need certainty – renewable energy can continue to create opportunities for several regions the country for many decades with the right policies in place.
"We’ve always said that if you set us a target, we will beat it. We’ve hit the bulls-eye with a year to go, and it is time to start asking ourselves what comes next," Thornton said.
Thornton also believes the industry is on course to reach the original 41TWh, set in 2009 but reduced by climate change-sceptic prime minister Tony Abbott, in the next year as well.