Current Energy Source Distribution

Image Source

The image and table from wikipedia give an idea of the proportional contribution of different energy sources. Wikipedia tends to underestimate energy reserves of various types such as fossil fuels and geothermal, and to overestimate near-term potential of wind and solar. Even so, one can derive a rough picture of energy consumption and reserves by browsing the link above.

Replacing fossil fuels within the next few decades will be incredibly difficult, short of a breakthrough in fusion energy. Much better to develop clean and responsible methods of using coal, heavy oils, oil sands, oil shale, and nuclear energy--to bridge the next few decades until renewables such as solar, geothermal, and biomass can come into their own.

Fuel type	Power in TW[1]	Energy/year in EJ
Oil	5.6	180
Gas	3.5	110
Coal	3.8	120
Hydroelectric	0.9	30
Nuclear	0.9	30
Geothermal, wind, solar, wood	0.13	4
Total	15	471