Question

Study the graph.

A graph titled Renewable Energy Consumption by Source from 1949 to 2011 shows years on the x-axis, from 1950 to 2011, and Quadrillion B t u on the y-axis, from 0 to 4. The graph shows the usage for hydroelectric power, wood, biofuels, wind, and other. Hydroelectric power has the highest usage, and wind has the lowest usage.

In what time period did hydroelectric power usage reach its peak?

1970–1980
1980–1990
1990–2000

Answer 1

1970–1980

The hydroelectric line on the graph reaches its highest point during the 1970s and then levels off or declines afterward.