The provided bar graphs illustrate the electricity generation in the United States from various energy sources, comparing data from the years 2009 and 2019.
Overall, the data indicates a notable decline in the production of electricity from non-renewable sources, particularly coal and petroleum, while renewable energy sources, especially wind and solar, have experienced substantial growth.
In the first graph representing non-renewable energy sources, it is evident that natural gas has emerged as the dominant energy source, with its output soaring from 921 billion kilowatt-hours in 2009 to an impressive 1582 billion kilowatt-hours in 2019. In stark contrast, coal, which was the leading source in 2009 with 1756 billion kilowatt-hours, saw a significant reduction in its production, plummeting to 966 billion kilowatt-hours by 2019. Additionally, nuclear energy demonstrated slight growth, increasing from 799 billion kilowatt-hours to 809 billion kilowatt-hours. Petroleum continues to lag, being the least utilized non-renewable resource in both years, decreasing from 57 billion kilowatt-hours to 40 billion kilowatt-hours.
The second graph details the breakdown of renewable energy sources. Notably, wind energy has surged dramatically, producing 300 billion kilowatt-hours in 2019, up from just 94 billion kilowatt-hours in 2009. Solar energy has also made significant gains, rising from a mere 1 billion kilowatt-hour to 73 billion kilowatt-hours. Plant and animal matter contributed between 54 and 58 billion kilowatt-hours across both years, while geothermal production saw a marginal increase, rising from 15 billion kilowatt-hours to 16 billion kilowatt-hours. Interestingly, hydroelectric power maintained a stable output of 273 billion kilowatt-hours in both 2009 and 2019, illustrating its consistency as a renewable energy source.