Final answer:
Hydroelectric power accounts for approximately 2.7% to 2.8% of the total energy production in the U.S., a notably small fraction compared to the dominant source, fossil fuels.
Step-by-step explanation:
About 2.7% to 2.8% percent of total energy production in the U.S. is hydroelectric power. This percentage corresponds to the hydroelectricity's contribution to the nation's total energy consumption and electricity supply. While the figures might vary slightly depending on the source, it is clear that hydroelectric power constitutes a small fraction when compared to other energy production forms, especially fossil fuels which make up about 80% of the U.S. energy production. The hydroelectric capacity factors also provide insight, with the national average being 0.4, meaning that over the course of a year, dams deliver 40% of their rated capacity, which is influenced by seasonal water flow.