The U.S. GDP to power utilisation ratio (billions of 1987$ to quadrillion BTUs). There are two distinct time span, pre- and post-1974. The effectiveness of aggregate power use increased in the first half of the 1950s, dropped in 1955 and stayed stable until 1966. At this issue power use expanded relation to GDP until 1970, when it leveled off for three years. During the time span 1949 to 1970 the relation power cost skilled no foremost fluctuations. Between the first oil cost alarms in late 1973 and 1982 the relation composite power cost expanded 500%. Energy effectiveness increased slowly; it ...