Pipes for TransCanada's planned Keystone XL pipeline are stored in Gascoyne, N.D. The U.S. House has voted to approve the proposed project, which would allow crude oil to flow from Canada to the Gulf of Mexico. The Senate plans to vote Tuesday on legislation that would greenlight the project. Andrew Cullen/Reuters/Landov hide caption

itoggle caption Andrew Cullen/Reuters/Landov

Pumpjacks at the Inglewood oil fields in California in March. Some of the most controversial methods of oil extraction, like fracking, oil sands production and Arctic drilling, are also expensive. That's made them less profitable as the price of oil continues to fall. Richard Vogel/AP hide caption

itoggle caption Richard Vogel/AP

Former South Carolina Republican Rep. Bob Inglis now runs the Energy and Enterprise Initiative. /Energy and Enterprise Initiative hide caption

itoggle caption /Energy and Enterprise Initiative

President Obama gestures during his speech on America's energy security, Wednesday, March 30, 2011, at McDonough Gymnasium at Georgetown University Pablo Martinez Monsivais/AP hide caption

itoggle caption Pablo Martinez Monsivais/AP