A system for use in transport vehicles includes an auxiliary power unit (APU) for a transport vehicle, the APU having a locator unit for use in a tracking and monitoring system 5 for communicating over a communication network. The locator unit can be attached to or installed within the APU or any other form of auxiliary provided power. Furthermore, the locator unit can have multiple sensor inputs that can read and store sensor data, including location information and emissions output. Then, the locator unit can transmit that information to a remote monitoring station or can use that information to calculate emission reduction data information for conversion to one or more emission reduction credits.