A $200-million pipeline delivering natural gas to two of Alberta's largest power plants is a real-world, practical solution to the challenges of climate change, Premier Jason Kenney said Friday.

The Pioneer Pipeline supplies natural gas to TransAlta's electricity generating units at Keephills and Sundance, 70 kilometres west of Edmonton, as part of the Calgary-based power producer's move away from coal as a fuel source.

"The pipeline we just opened here today is a real, practical solution to reducing greenhouse gas emissions," Kenney said at an event to mark the pipeline's completion.

"This is a good day for Alberta jobs, a good day for diversifying our economy and it's a good day for the environment."

At the same time Kenney was at the pipeline event, a climate rally was being held at the legislature in Edmonton, led by 16-year-old Greta Thunberg of Sweden.

Thunberg announced last weekend she would visit Alberta this week. Kenney said the date for the "historic" pipeline announcement was set three months ago. He also said he hadn't been asked to meet with Thunberg.

Canada plans to phase out coal as an energy source for electricity generation by 2030.

Alberta produces 50 per cent of its power from coal and 39 per cent from natural gas, according to the Canada Energy Regulator.

The 120-kilometre Pioneer Pipeline connects the Keephills and Sundance plants with Tidewater Midstream's Brazeau River Complex, a gas plant west of Drayton Valley. TransAlta and Tidewater own the pipeline in a 50/50 joint venture.

The 20-inch pipeline transported its first gas in late May. Beginning Nov. 1, it will flow 130 million cubic feet per day, expanding to 440 million cubic feet per day once TranAlta finishes converting its generating units to natural gas.

The project went from conception to completion in 21 months, Tidewater Midstream president Joel MacLeod said. He noted that it took only 14 months between the final investment decision and the first gas deliveries.

Of 106 vendor contracts, 103 went to Western Canadian companies, he said. More than 25 per cent of the $200-million construction budget went to "First Nation-affiliated partners," he said.

TransAlta plans to convert three of its existing Alberta thermal units to gas in 2020 and 2021 by replacing coal burners with natural gas burners.

TransAlta CEO Dawn Farrell said the Calgary-based power producer has committed to spending more than $1 billion over the next five years converting coal-fired generating plants to natural gas.

"By the time we're finished, we will reduce our greenhouse gas emissions by 50 per cent," Farrell said.