Overall, petroleum and oil remain by far the most widely consumed fuels throughout the period and are expected to continue increasing. Coal also shows a significant upward trend and eventually overtakes natural gas, while nuclear, solar or wind, and hydropower account for much smaller proportions and experience only modest changes.
In 1980, petroleum and oil were consumed at approximately 35 quadrillion units, considerably higher than any other fuel. Although consumption declined slightly in the mid-1980s, it rose steadily thereafter, reaching around 48-50 quadrillion units by 2030. Coal started at roughly 16 quadrillion units and increased gradually to about 30 units by the end of the period. In contrast, natural gas fluctuated around 20-25 quadrillion units and is projected to remain relatively stable at approximately 25 units after 2015.
The remaining energy sources were consumed in much smaller quantities. Nuclear power increased gradually from around 4 to about 7 quadrillion units between 1980 and 2030. Similarly, solar and wind energy rose steadily from approximately 2 to around 5 units. Hydropower, however, remained the least significant source, fluctuating only slightly at around 3 quadrillion units throughout the entire period.