The pie charts illustrate the primary energy sources in the United States over two decades. As shown, oil remained the dominant energy source in the USA during both the 1980s and the 2000s. However, there was a noticeable decrease in the use of oil and coal, with nuclear power partially filling the gap left by these sources.
In the data provided, oil accounted for 42% of the total energy supply in 1980, making it the primary energy source at that time. The second-largest source was natural gas, which contributed 26% of the total energy. Coal also played a significant role, supplying just over 20% of the energy demand. Meanwhile, hydroelectric power and nuclear energy each supplied 5% of the total energy.
By the next decade, nuclear power had increased its output, providing 10% of the total energy, which was nearly double its contribution from the previous decade. Hydroelectric power remained stable, still supplying 5% of the total energy in this period.
The other major energy sources, coal and natural gas, saw little change during this decade. Notably, the use of oil decreased to 33%, which is nearly 10% less than its contribution in the 1980s. Despite this reduction, oil remained the largest energy source in the 2000s.