Relation of plant design to reserve capacity

BECAUSE of conditions beyond the control of the electric power industry during and following the recent war years, the margin of capacity available for reserve has dropped to values generally considered to be below the standard that will assure continuity of service under reasonably forseeable contingencies. With the addition of some 4,141,500 kw of net name-plate capacity during 1948, the year-end margin of reserve was only 5 per cent of the annual peak demand. The planned addition of some 6,700,000 kw of capacity during 1949 will increase the margin of reserve to an estimated value of but 8 per cent, and with planned capacity additions for succeeding years it is not expected that a satisfactory margin of reserve, which in most areas is now considered to be around 15 per cent, will be available until the end of 1951.