The $500m plant is equipped with 12 turbines and is located in the town of Coolidge.
US-based utility Salt River Project has signed a 20-year power purchase arrangement to purchase power from the facility.
The natural-gas fired has the capacity to generate enough power to meet the needs of approximately 575,000 homes.
The project, which began in 2009, has been completed on time and on schedul,e and is expected to generate revenue to state and local governments.
TransCanada is a provider of gas storage and related services.
