Hydro-Québec, Learning Section

Back to Power Transmission   Power Transmission over Long Distances

Electricity often travels over very long distances to reach urban load centres. For example, the distance between James Bay–where water from the Grande Rivière ends up after driving the turbines in eight power stations–and Montréal is about 1,000 kilometres as the crow flies. However, the farther electricity must travel, the greater the risk that part of it will be lost on the way. Since utilities invest heavily in the high-volume transmission of power over long distances, they take special steps to limit these transmission losses.

High-voltage transmission, a solution perfected by Hydro-Québec
Link: Live-line work: A power job
Live-line work: A power job

Radisson substation

When moving large volumes of electricity, it's better to increase voltage instead of current intensity (amperage), in order to reduce energy losses and line construction costs. A large portion of the power generated by Hydro-Québec is transmitted using 735-kV lines. Without these high-voltage lines, the landscape would be cluttered with towers. One 735-kV line is equal to four 315-kV lines, the next voltage level down. In fact, Hydro-Québec is a pioneer in high-voltage power transmission: it developed the world's first commercial 735-kV line, as well as the earliest equipment designed for that voltage.

Link: World first by Hydro-Québec
World first by Hydro-Québec

Image: La Vérendrye substation
La Vérendrye substation


Next >>>


Top of page Hydro-Québec Home Learning Home Page