A $1.5-billion power line project through the Edmonton-Calgary corridor has been approved.

Late Thursday afternoon, the Alberta Utilities Commission (AUC) gave AltaLink the go ahead to build the Western Alberta Transmission Line.

The high-voltage line will run southwest of Edmonton for 350 kilometres down along Highway 2.

It will then cross over the highway north of Crossfield and travel south down to Langdon.

The utilities commission says about 60 per cent of the approved route parallels existing power lines, which it says will minimize the visual and environmental impacts.

"The route was a combination in the end of what was submitted by the applicant and some suggestions that came forward by the landowners and were able to be incorporated as we progressed," said John Law with the Alberta Utilities Commission.

"In the end what I think we have here is a route approval that basically minimizes disturbance to the land itself and the impact on the landowners along the route."

Last month, the commission approved a similar line for the eastern part of the province. 

Both projects have caused controversy with some landowners — critics have called them a "massive overbuild".

Some say the power lines are unnecessary and will set the stage for Alberta to start exporting power to the U.S.

However AltaLink CEO Scott Thon disagrees.

"This project is absolutely 100 per cent for Albertans and it is about reliability in our system and making our generation sector more competitive," Thon said.

The government says reinforcing Alberta's transmission system will spark new investment in electrical generation plants. It believes that will lead to increased competition and lower electricity costs.

The cost of the two lines is estimated at $3 a month for residential customers.

The Critical Transmission Review Committee was appointed last fall by Premier Alison Redford.

Committee members held public hearings in Edmonton and Calgary in January on the need for two projects.