Construction of the $942 million facility began in late 2005 and was expected to be completed by June 2007, with full combined cycle operations to begin in July 2008.

[7] In 2015, Goreway had settled with the Independent Electricity System Operator (IESO) to repay an undisclosed amount for exploiting loopholes in the wholesale energy market over several years.

However, the IESO defended the proposed expansion on the grounds that there were "no like-for-like replacements with similar operating flexibility for natural gas generation.

"[12] In October 2023, the Toronto Star reported that the Goreway plant, which was intended to only operate during peak periods of electricity demands, had been running for 10–15 hours each day between 2019 and 2023.

On 3 March 2011, Sithe Global Power announced that it had sold its remaining 50 per cent stake to Chubu Electric and Toyota Tsusho.