The Electrical Development Company (1906) represented a cabal of Toronto-based financiers which included Henry Pellatt, who would later build Casa Loma, and various other principals associated with the Bank of Commerce, the National Trust, the Toronto Electric Light Company and Street Railway, and the Canadian General Electric.

The Toronto Power Generating Station, formerly the Electrical Development Company began producing power in November of 1906. Located above the Horseshoe Falls, the powerhouse was built out of Indiana Limestone and is an impressive 462 feet long and 91 feet wide. It was built on reclaimed land from the river bed. The grounds on which the plant now stands were once submerged by as much as 24 feet of water.

This plant diverted water from the Niagara River, which was taken from the rapids by a wing dam. The water then passed down into a series of penstocks and into an intake gate to control the flow. Water discharged from the turbines would then move down a 2,000 foot outlet tunnel which ran under the Horseshoe Falls and led out into the curtain of water. The plant had eleven machines which each produced 11,000 horsepower, with a total capacity of approximately 98,000 kilowatts.

The plant was shut down by Ontario Hydro on December 31st, 1973.