The line graph illustrates sources for producing electricity in the USA from coal, nuclear power, natural gas and water power, and also the total from all sources throughout the period from December 2007 and November 2008.
Overall, all sources recorded the highest score and fluctuated during the whole period. The most pronounced disparity was observed between coal and water power, where coal significantly higher than acquatic sources.
In detail, coal experienced approximately 170 terawatt-hours at the beginning, and then started to vary marginally before reaching its peak on July (about 190 TWhs). Meanwhile, water power recorded the lowest figure among all the sources, which had only about 15 TWhs at the beginning, and then began to fluctuate moderately and finished with the same result at the end of the year (November).
Although nuclear power and natural gas were almost matching from the start, natural gas rapidly jumped from 60 TWhs to 100 TWhs over three-month period (between May and July), whereas nuclear power remained moderately unchanged. From August to November natural gas began to steadily go down and matched with nuclear power again. Overall, all sources experienced the leading position and varied substantially before reaching its high point with 400 TWhs in July and afterwards decreased quickly.