Energy comes in various raw forms. Oil and coal remain the basic energy sources but they cause pollution, a costly local problem. There are ample supplies of coal, the main fuel for electricity generation, but pollution concerns may limit coal burning or require very expensive scrubbing. Either way, get ready for higher electricity bills. As oil is depleted over the coming decades, its price will rise exponentially.
Natural gas is a popular fossil fuel because it burns cleanly.
Natural gas from the Gulf Coast comes up the slowly expanding pipeline system to a new generation of efficient gas turbine generators. But the pipeline system is expanding much more slowly than demand and natural gas prices will climb steadily with increasing scarcity. To complicate matters, all fossil fuels release carbon dioxide that may be limited by international agreements on global warming. Nuclear reactors run on cheap uranium but nobody knows what to do with the radioactive waste. The nuclear generators in use are getting old and no new ones are being built or even planned.