The Energy Industry is one of the largest on the planet and provides the industrial oxygen for all economies. Right now over 1.3 billion people are without access to electricity and 2.7 billion people rely on the traditional use of biomass (lets call this wood) for cooking, which causes harmful indoor air pollution. Imagine not being able to flip the switch and have the lights come on or turn on the stove when it's time to cook. On earth their are approximately 7 billion people and it is the job of the Energy Industry to power the planet without for all of them, without killing it.
Oil: Currently oil is one of the most valuable commodities on earth and powers more than 90% of all transportation. The world uses 85 million barrels a day. At 42 gallons to the barrel, that's three billion, five hundred and seventy million gallons of oil (3,570,000,000). Oil is used in transportation, manufacturing, petrochemicals, agriculture, renewable energy, power generation and just about every other industry on the planet.
Natural Gas: A lighter and more abundant cousin to oil, natural gas is primarily used for direct heat (warming the house or cooking), power generation, industrial plastics, fertilizer and it is seen as a competitor for oil in transportation. It has numerous advantages over it's dominate cousin. It is more abundant, it is less expensive, it produces fewer harmful emissions and as technology advances it has increasingly more utility. It can offset traditional hydrocarbon fuels for transportation when compressed or liquefied. The U.S. Energy Information Administration (or EIA) forecasts that total natural gas consumption will average 75.7 Bcf/d (billion cubic feet per day)
Coal: Coal is seen as the work horse of power generation around the planet. Inexpensive to produce, cheap to burn and high in carbon it makes an almost ideal source of energy. Currently coal provided approximately 40% of the world’s electricity needs. And at 29% of total world energy supply, coal is second only to oil, at 31%. Coal, while a primary source of electricity in all industrialized countries has it's drawbacks. Countries like China that rely heavily on coal are experiencing serious health issues related the emissions that result from its use. Back in the early 19th century London fog was the result of consistent coal burning and turned the limestone buildings black. Today the hunt is on for "clean coal" but technology has been slow to provide a widely deployable inexpensive solution, causing countries like China and India to choose between air quality and much needed inexpensive power for their people.
Nuclear Energy: Nuclear Energy is the fourth leg in the stool for Energy on a global basis. Currently nuclear power is used for power generation in all industrialized nations. However, it has not come without some setbacks. In the United States Three Mile Island is credited with stifling the industry. In Russia the Chernobyl disaster underscored the dangerous impact a nuclear disaster could have and most recently Fukushima Japan was the location of a disaster that changed the profile of an entire countries energy use. All that being said, nuclear power is emission free, it is reliable, used in power generation and in marine transportation (nuclear submarines and air craft carriers). There are currently 435 operable civil nuclear power nuclear reactors around the world, with a further 71 under construction. They provide over 11% of the world's electricity as continuous, reliable base-load power, without carbon dioxide emissions, and 180 nuclear reactors power some 140 ships and submarines.
Renewable Energy: The largest source of renewable energy on the planet is hydro electric energy. Hydroelectric energy produces roughly 16% of electricity worldwide, behind coal and gas, but ahead of nuclear. As such it accounts for 83% of all renewable energy produced on the planet. Currently there are 90 major dams producing power around the world, but the ability to expand this source is limited. There are serious consequences to dating rivers and valleys needed to generate large amounts of electricity. All other renewables combined including wind, solar, geothermal and biomass generate less than 3% of the World's energy mix and while important will not contribute significantly in the foreseeable future.