You should spend about 20 minutes on this task.
The diagram shows the consumption of renewable energy in the USA from 1949-2008.
Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
Model answer
The given line graph shows the main sources through which renewable energy is produced in USA and also tells about its total consumption from 1949 to 2008.
Water and wood have been the main means of producing energy. Initially from 1950 to 1960 the energy provided by them has approximately been same being 2 Quadrillion BTU, but from 1960 to 1980, the production of hydroelectric power doubled than fuel provided by wood. This increased trend of making energy through water is consistent with the total energy usage. The generation of energy through biofuels and wind was introduced in 1980. Since then, they have made a contribution of less than 1 Quadrillion BTU in production of total energy. Yet this is a significant contribution as the overall consumption of energy increased in subsequent years reaching up to a maximum of 7 Quadrillion BTU by 2008. It just dipped in 2000 because hydroelectric power also decreased during this time, but then they both rose again.
The changing trends in gross energy consumption are consistent with the generation of hydroelectric power signifying it as the major source of energy production. Wood has been the second most important source, while biofuels and wind made little contributions.