Keephills 3 under construction as of August 2010.
TransAlta Corp. deliberately timed outages at power plants in Alberta at peak times in order to drive up electricity prices, the province's utilities commission said in a ruling Monday.
The Alberta Utilities Commission launched an investigation after the province's market surveillance administrator alleged that the Calgary-based company manipulated the electricity market by shutting down power plants in 2010 and 2011 to drive up power costs during periods when demand was high.
"The commission concludes, based upon clear, cogent and convincing evidence that TransAlta could have deferred each of the above described outages to off peak hours but chose instead to take them during peak or super-peak hours so as to maximize the benefit to its own portfolio," the commission said in its decision.
But the commission found that the market surveillance administrator did not prove allegations that TransAlta's compliance policies, practices and oversight were inadequate and deficient.
TransAlta could not immediately be reached for comment Monday. But the company has previously denied all of the allegations, calling them "categorically false" and saying that it triggers outages for maintenance, operations and safety purposes.
The commission said it will resume proceedings later to determine what penalties to impose against TransAlta.