National Defense Energy Savings Act of 2003 - Authorizes the Secretary of Defense to: (1) enter into an energy savings performance contract (for a period of up to 25 years) for the sole purpose of achieving ancillary energy savings and benefits; and (2) incur obligations under the contract to finance energy conservation measures so long as guaranteed savings exceed the debt service requirements.
Directs the Secretary to issue final rules establishing implementation procedures and methods that meet specified requirements.
Authorizes the Secretary to implement a pilot program to enter into up to ten energy savings performance contracts in nonbuilding applications.