These two pie charts demonstrate the amounts of energy sources contributing to supply usage in the US in the two decades following the 1980s.
Overall, it can be seen that while oil remained the main source of energy, natural gas lost its second place and was replaced by coal. Also, the figure for hydroelectric power witnessed no change, and nuclear power saw an increase.
Focusing on fossil fuels, oil contributed 42 percent to the USA’s power usage in the first decade, and this amount decreased to 33 percent in the 1990s. Natural gas saw a small fall from 26 percent to 25 percent while, in contrast, coal’s figure increased by 5 percent, starting from 22 percent in the 1980s.
Regarding other power sources, energy production based on hydro systems did not change between the two decades and remained at 5 percent. However, nuclear power started at 5 percent and its amount doubled in the 1990s.