The supplied line graph represents a comparative data on the amount of renewable energy consumed in Great Britain over a 59-years period in 1949 and 2008.
At first glance, it is clear that the amount of energy produced by hydroelectric power plants remained the highest, while the lowest figures were for biofuels and wind which started generating energy only in the 1980s. Moreover, the rates for all categories, including the total amount, almost flactuated constantly, with the exception of wind and biofuels.
Turning to the details, for the first 5 years, the amount of energy produced by burning woods and hydroelectric power plants remained stable at around 1,5 quadrillions Btu. However, the latter category experienced the significant increase over the next 30 years, reaching approximately 3 quadrillions in 1975, while the figure of wood grew to rougly 2.5 quadrillions only between 1975 and 1980. Furthemore, over the next 28 years, there was the constant fluctuation in these rates between around 2 and 3 quadrillions Btu of renewable energy for both categories.
In 1981, biofuels and wind energy production was appeared, and for the next 20 years, constitute the smallest quantities of Btu which were almost zero. Nevertheless, both figures saw a significant climb at the beginning of the 21st century, reaching approximately 1 and 1,5 quadrillions Btu, respectively. Regarding the total amount of energy, it increased moderately from 3 to almost 5 quadrillions for the first 25 years. However, there was a small drop in 1977, after which the figure started fluctuating between roughly 5 and 7 quadrillions, exceeding 7 quadrillions in 2008.