Despite the promise of alternative energy sources — more appropriately called renewable energy, collectively they provide only about 7 percent of the world’s energy needs (Source: Energy Information Agency).
This means that fossil fuels, along with nuclear energy — a controversial, non-renewable energy source — are supplying 93 percent of the world’s energy resources.
Nuclear energy, which is primarily generated by splitting atoms, only provides 6 percent of the world’s energy supplies.
And it is not likely to be a major source of world energy consumption because of public pressure and the relative dangers associated with unleashing the power of the atom.
Yet, governments such as the United States see its vast potential and are placing pressure on the further exploitation of nuclear energy.
The total world energy demand is for about 400 quadrillion British Thermal Units — or BTUs — each year (Source: US Department of Energy).
That’s 400,000,000,000,000,000 BTUs!
A BTU is roughly equal to the energy and heat generated by a match.
Oil, coal and natural gas supply nearly 88 percent of the world’s energy needs, or about 350 quadrillion BTUs. Of this amount, oil is king, providing about 41 percent of the world’s total energy supplies, or about 164 quadrillion BTUs.
Coal provides 24 percent of the world’s energy, or 96 quadrillion BTUs, and natural gas provides the remaining 22 percent, or 88 quadrillion BTUs.
http://www.ecology.com/2011/09/06/fossil-fuels-vs-renewable-energy-resources/