The paper deals with the electrical aspects of the Nechako–Kemano–Kitimat hydro-electric power development and the associated aluminium-reduction works in the province of British Columbia, Canada.After briefly presenting the physiographic setting and civil-engineering features of the world's largest underground power development, with an ultimate installed capacity of 2,240,000 h.p., the paper discusses the outstanding features of many elements of the power development wherein new engineering ground has been broken. The unusually heavy electrical loading of the 300-kV transmission system is treated at some length, as well as the mechanical loading.In addition, the plant power-supply features of what will ultimately be the largest aluminium-reduction works in the world, at Kitimat, are discussed.The paper presents comparative data on the characteristics of such equipment as the impulse turbines, generators, main step-up and step-down transformer banks, and 300-kV power cables, derived from the tenders of the several manufacturers supplying the equipment.