The 2.3MW solar farm adjacent to the Mount Majura winery will generate 4,300 MW per hour within a year, which equals about 600 houses.

Four years since planning began, the 5000 panels at the $6.5 million farm are finally helping the ACT reach its 100 per cent renewable energy target.

The farm has one of the first self-powered and single axis tracking technology to be used in Australia, which increases output by up to 40 per cent.

Lane Crockett, head of renewable infrastructure from the Melbourne-based Impact Investment Group, which owns and operates the farm, said the project ran relatively smoothly.

It struck objections from Canberra Airport when it was first proposed because of the concern solar glare could blind pilots on the northern landing approach, and that the land on which the farm was being developed was subject to withdrawal clauses because it was in a transport corridor.

But the Civil Aviation Safety Authority ruled out the safety concerns soon after and Mr Crockett said there had been no major hiccups since.

"Interestingly we've just done a solar farm in Karratha which is part of the airport so solar farms are becoming very acceptable around airports these days," he said.

"Because of the simple technology at this [Majura] farm that follows the sun, there were relatively few challenges for this particular solar plant, although there are always small challenges."

Majura's solar farm is the first asset of the group's target $100m Solar Income Fund.

Impact Investment Group is also building the Williamsdale solar farm, 20 kilometres east of Canberra, which will use the same tracking system.

ACT Chief Minister Andrew Barr said the completion of Canberra's fourth solar farm - with the others in Mugga Lane, Williamsdale and Royalla - helped ensure Canberra's future renewable power supply was guaranteed.

When asked about concerns that renewables could have contributed to South Australia's prolonged blackout during an extreme weather event in September, which is the subject of a detailed report, Mr Barr slammed those who blamed the wind farms.

"What is demonstrated was just how opportunistic and shallow the conservative side of politics are when it comes to renewable energy use," Mr Barr said.

"The Prime Minister who once was allegedly an advocate for renewable energy came out with a statement that the renewable energy targets we had were unachievable. We are demonstrating right here on this site that our target is achievable."

He said the ACT government had contracted 640 megawatts of power which exceeded the amount needed to make the territory entirely renewable by 2020.