The Edmonton-based utility, which has assets in both Canada and the United State, blamed the loss on a $73-million non-cash writedown of deferred tax assets as well as the timing of both unplanned outages and the extension of a planned outage in the quarter.
Revenue in the period totalled $248 million, down from $380 million.
"Financial results in the third quarter were below our expectations, primarily due to an extended planned outage and unplanned outages at the acquired Sundance PPA units and other plant derates," president and CEO Brian Vaasjo said in the earnings release, issued Friday after markets closed.
Vaasjo said the outages occurred primarily in July when Alberta spot power prices averaged $122 per megawatt hour.
"As a result, with commercial production 100 per cent sold forward in July, we were required to cover a short market position that negatively impacted our portfolio optimization position in the quarter," he said.