ACT will support a further 200MW of wind capacity, following a reverse auction, at an average price of A$79.80/MWh ($60.75/MWh) for 20 years.
Neoen's 109MW Hornsdale phase three project has received support at A$73/MWh ($55.57/MWh)
It will comprise 35 turbines at a site 200km north of Adelaide, South Australia, and 1,000km west of ACT. Once the three stages have been completed, the project will have 315MW of installed capacity.
The first two phases of Hornsdale, with a combined 200MW of nameplate capacity, will supply power to ACT. The first phase, under construction, will supply power at A$92/MWh.
Hornsdale's second phase, where financing was arranged in June, will supply power at A$77/MWh following an auction in December 2015. Both phases will be powered by Siemens 3.2MW turbines.
"Neoen has set a target for 2020 to achieve 1,000MW of competitive renewable energy assets in Australia. Hornsdale Stage 3 brings the company one step closer to achieving this target," said Neoen Australia managing director Frank Woitiez.
The second project to be supported by ACT is Union Fenosa Wind Australia's 91MW Crookwell 2 project in neighbouring New South Wales (NSW). It will receive A$86.60/MWh ($65.92/MWh), which ACT said was a new low for NSW.
Union Fenosa Wind is the Australian subsidiary of Spanish developer Gas Natural Fenosa. The 28-turbine project is the company's first in Australia and is expected online in 2018.
"It is with great satisfaction that the Government can announce this final piece of our plan. These two wind farms will lift our renewable energy percentage to 100% by 2020 and secure the achievement of our emission reduction goals in that year," said ACT minister for environment and climate change Simon Corbell.