Defense Siting Clearinghouse Improvement Act of 2017 This bill requires the Department of Defense (DOD) to establish a Defense Siting Clearinghouse to serve as a clearinghouse to: (1) coordinate DOD review of applications for energy projects filed with the Department of Transportation (DOT) and received by DOD from DOT, and (2) accelerate the development of planning tools necessary to determine the acceptability to DOD of proposals included in an application for an energy project.