Time Periods for the subsidies measured above:

Oil and Gas - 1918-2009.

Nuclear - 1947-1999

Biofuels and Renewables: 1980-2009 & 1994-2009

The recent fiscal troubles in Washington have led to many federal programs being questioned and reevaluated, among them energy subsidies. Some members of Congress have pointed to the fact that fossil fuel and clean energy subsidies have achieved parity in recent years, and have called for the elimination of all energy subsidies as a result. A recent report by DBL investors has tried to place this contentious debate in context, showing that energy transitions over the past century have been heavily subsidized by the federal government. After looking at the historical average, the researchers were able to demonstrate that "current renewable energy subsidies do not constitute an over-subsidized outlier when compared to the historical norm of energy sources of energy."

Source: DBL Investors, What Would Jefferson Do? The Historical Role of Federal Subsidies in Shaping America's Energy Future. September 2011.