 From 2003 to 2005 Sell worked in the White House as a Special Assistant to President George W. Bush, serving on the staff of the National Economic Council and in the Office of Legislative Affairs, where he coordinated the development and implementation of the administration's energy policy.From 2005 through 2008, he served as chief operating officer of the Department of Energy, he assisted the Secretary with policy and programmatic oversight of a 23 billion dollar budget with over 100,000 employees.Sell also played a role in maintaining and strengthening the economic national security while supporting scientific and research missions conducted by the Department.