When the 150 MW Unit 5 went into production in 1970, the Trenton plant was the largest single thermal generating station in the Atlantic Provinces at that time.

The initial boilers (Units 1 to 4) were designed to burn coal mined nearby in Pictou County as well as on Cape Breton Island.

However, both Trenton units have electrostatic precipitators designed to capture 99% of fly ash emissions from coal burning.

The plant is equipped to receive coal from barges entering from the Northumberland Strait through Pictou Harbour; the Trenton Connector Road runs immediately north of the plant and is equipped with a draw-bridge over the East River of Pictou, although the bridge is rarely operated.

[5] Unit 5, built at a cost of around $27 million, was officially opened by Nova Scotia premier George Isaac Smith and federal manpower minister Allan MacEachen on 6 July 1970.