Ark Energy announced on Tuesday it would supply the telecommunications giant with renewable electricity from the 923.4 megawatt MacIntyre Wind Farm being built 50 kilometres south-west of Warwick.

Telstra has bankrolled more than $1 billion of renewable energy projects across Queensland, Victoria and NSW as it targets 100 per cent renewable energy use by 2025.

Telstra's technology boss Kim Krogh Andersen said the major power purchase agreement (PPA) with Ark would also help insulate the telco from spikes in wholesale electricity prices.

"Our annual power bill is equivalent to 300,000 household power bills, so signing long-term renewable energy agreements helps us to manage our costs," Mr Krogh Andersen said.

Set to be the largest in Australia when it opens in 2025, the MacIntyre is also one of the world's biggest onshore wind farm projects.

Mr Krogh Andersen said backing renewable energy projects would not only reduce Australia's reliance on carbon-intensive fossil fuels, but also made economic sense as investments.

He said Telstra had more work to do to achieve the 2025 target and planned to partner with other high-quality generators.

Ark Energy owns a 30 per cent stake in the wind farm, which is part of a 180-turbine precinct being developed by Spain's ACCIONA Energia.

Daniel Kim, CEO of Ark Energy, said the deal with Telstra was part of a commitment to support large commercial and industrial customers to go carbon neutral and speed up Australia's transition to renewable energy sources.

Ark's share will also be used to power the Sun Metals zinc refinery in Townsville.

The PPA agreement with Telstra is subject to Ark finalising financial arrangements.

Australian Associated Press