The pie charts illustrate the principal sources of electricity production for USA in 1980 and 1990. Overall, there was a decrease in the percentage of natural gas and oil, while the opposite was true for coal and nuclear energy. Additionally, hydroelectric energy maintained the same level in the second level.
In 1980, oil beame the most important feul source in the USA, which was 42% of country’ electricity. Natural gas was the second main source with 26%. Not too far behind was coal, which comprised 22%. Notably, the percentage of hydroelectric and nuclear energy came last with the same level, which standing 5%.
By 2010, the figures in the mix had shifted considerably. The proportion of oil decreased considerably, at 33%. The percentage of natural gas went down only by 1% (25%). The share of coal and nuclear power increased gradual by 5%, the former standing at 27% and the latter amounting for 10%. Lastly, the percentage of hydoelectric enengy remained unchanged to 5%.
