The graph illustrates the variations in the electricity productions in USA by using 5 different sources during 1980 and 1990. Units are measured in percentage.
Overall, it can be considered that the rate of electricity production from oil, which was the most significant component of the chart in 1980, experienced a considerable decline over the period; however, it remained as the major source of energy in 1990 as well.
Initially, the three main sources of energy in 1980 were oil, natural gas and coal, with 42%, 26% and 22% respectively. While the electricity output from oil and natural gas decreased by 11% and 1% in 1990, the rate of electricity production by coal experienced a 5% increase over the decade.
On the other hand, the proportions of electricity produced from hydroelectric power and nuclear power were both at 5% in 1980. In 1990, nuclear power manufactured one-tenth of the total proportion, whereas hydroelectric power remained as the least useful source of energy over the ten-year period.