This thesis provides a detailed account of the spatial evolution of present electric power capacity in Canada. The patterns of diffusion of electric power stations through the twentieth century are identified. Early electric power capacity was mainly in hydro-electric stations. As available hydro-electric potential became more remote the importance of thermal-electric capacity located closer to centers of demand increased nationally, with interesting regional variations. This shift was accompanied by the concentration of capacity in stations of larger size and the growth of electric power systems to supplant the dispersed pattern of stations with localized service areas. Utilities, especially those publicly-operated, have accounted for an increasing share of growth. Fuel costs are identified as a major determinant of the level of thermal-electric development, as are the capital and transmission costs associated with the development of remote hydro-electric potential. The analysis results in the conclusion that the huge future growth will be mainly within very large stations showing a close orientation to major centers of demand as thermal-electric stations, especially nuclear, Increase in relative importance. An Atlas bound separately forms part of this thesis.