Since federal limitations on domestic oil production in the 1980s, there has been a steady decline in US production. By 1994, the US was importing more than its total domestic production. Restrictions on supply help to drive up prices and unnecessarily contribute to US reliance on foreign oil.
As much as 66 percent of all US crude oil is imported from other countries, and the amount of oil imported from OPEC nations is roughly equal to the amount of oil produced domestically. Petroleum, natural gas and coal are the primary sources of energy consumed in the United States because they are the most energy rich resources available. So far, renewables have only been capable of providing a small portion of total energy consumption, and their contribution to energy consumption has remained limited over the last two decades. However, with increasing government and private focus on green energy sources, renewables are likely to go from strength to strength in the near future.
Source : http://www.ngoilgas.com/