Environment Minister Simon Corbell believes the ACT is still a strong renewable energy "buyers' market" after receiving 15 proposals to supply Canberra with 200 extra megawatts of wind power from 2018.
The territory government's second large-scale wind energy auction closed bidding on Wednesday, having attracted only three fewer proposals than the last round in February.
The closure of bids in the "reverse auction" process, in which wind farms compete to be among two or three to supply the ACT with energy in exchange for a feed-in tariff, comes as the Department of Environment and Planning's annual report showed 18.5 per cent of the territory's energy was supplied from renewable resources in the last financial year.
The figure, up from 14.2 per cent in 2010/11, showed a major acceleration in renewable power uptake was needed if the government was the reach its target of green energy supplying 90 per cent of the ACT's needs by 2020.
But the document also notes successful wind farm bidders from the first auction are due to come online between 2016 and mid-2017, contributing to about 25 per cent of the ACT's expected electricity demand in 2020.
Mr Corbell said the winning farms from the most recent auction would contribute an additional 25 per cent of forecast 2020 demand to the supply, while solar farms launched between 2014 and 2016 would provide an additional three per cent.
"This second wind auction will cut over half of the emissions associated with electricity usage in each and every Canberra household," he said.
"Our early review of bid pricing indicates we are still in a very strong buyers' market."
The latest auction round was originally due to be held next year, but the government announced in August it would be brought forward while "market conditions are favourable".
The winners, expected to be named later this year, will be granted a 20-year government contract starting in 2018, during which they will be expected to reduce the ACT's greenhouse gas emissions by an estimated 11 million tonnes.
Among the bidders are expected to be wind farms in the ACT or just across the border, after they missed out in favour of Victorian and South Australian operations in the first round.
Solar farm "reverse auctions" in 2012 and 2013 preceded the wind energy proposals.
Seventy per cent of the ACT's renewable energy in 2020 is expected to come from large-scale projects like the proposed wind farms.
The remaining 30 per cent will be divided between rooftop solar generators, GreenPower purchases and the territory's contribution to the national renewable energy target.
The government plans for the bulk of renewable energy infrastructure to be in place by 2018, with a target of green energy supplying 80 per cent of electricity in that year.
That would leave only 10 per cent of power to be switched to renewables in the final two years before the target is achieved.
An interim report released earlier this year showed the ACT's greenhouse gas emissions had fallen 8 per cent between 2011/12 and 2013/14.