This book provides background information and identifies issues for Congress on Department of Defense (DOD) energy initiatives. The Department of Defense (DOD) spends billions of dollars per year on fuel, and is pursuing numerous initiatives for reducing its fuel needs and changing the mix of energy sources that it uses. DOD's energy initiatives pose several oversight issues for Congress, and have been topics of discussion and debate at hearings on DOD's proposed FY2013 budget. Congress' decisions on DOD energy initiatives could substantially affect DOD capabilities, funding requirements, and U.S. energy industries.