Supply and Demand Two profound questions loom over all other energy concerns: Will we have enough affordable energy in the near future? What will we do for the long term? The answers depend on our inventory of sources. At present, oil accounts for 40% of total energy consumption in the United States. Coal provides 23% and natural gas provides 22% of our energy. Another 8% comes from nuclear power plants. Renewable energy sources round out the roster, accounting for 7% of consumption -- mostly as the result of hydropower investments made in the last century and the use of biomass (organic matter such as wood, municipal waste, and agricultural crops) for energy production. Those sources and their proportions will have to change eventually, since the planet's known supplies of fossil fuels are limited. But during the next couple of decades, the nation's energy menu is unlikely to be substantially different from today's -- assuming "business as usual" conditions. That may be a lot to assume: Energy prices and availability aren't solely determined by the size of the supply. They're also affected by the economy, possible new laws and regulations governing energy choices (such as emissions of carbon dioxide and other gases), worldwide demand, the policies and political stability of petroleum-rich nations, lifestyle choices and business decisions, climate change, and the pace of developments in science and engineering. Any of these factors can change in a very short period of time. ... https://www.youtube.com/watch?v=rtg8otE-y9E

... https://www.youtube.com/watch?v=pYncp9R8Uwk