Wildrose MLA Joe Anglin criticized the hearing, saying that no evidence was allowed to be presented on the need for the line.
But AltaLink spokesman Scott Schreiner says the demand for electricity in the province has more than doubled over the last 30 years.
The Alberta Utilities Commission began hearing arguments for and against the line between the Edmonton and Calgary areas last month.
A decision on the proposed route is expected later this year.
The $1.4-billion, 500-kilovolt line would run through central Alberta west of Rimbey, Sylvan Lake and Olds.