Locomotive exhaust aftertreatment system

A method comprising:

• providing a locomotive exhaust treatment system, comprising:
• a generator having a generator exhaust outlet;
• an aftertreatment system including an aftertreatment system inlet,
• a mixing valve having a first inlet in fluid communication with a locomotive exhaust outlet of a locomotive, a second inlet in fluid communication with the generator exhaust outlet, a first outlet in fluid communication with the aftertreatment system inlet, and a second outlet, and
• a controller in operable communication with the mixing valve;
• flowing locomotive exhaust to the first inlet of the mixing valve;
• supplying power to the aftertreatment system and the controller from the generator, thereby causing generator exhaust to flow to the second inlet of the mixing valve;
• identifying a first system condition associated with the locomotive exhaust treatment system via the controller;
• and
• in response to the identified first system condition, controlling the mixing valve with the controller to do one of:
• direct an output gas to the aftertreatment system through the first outlet, the output gas comprising the locomotive exhaust, the generator exhaust, or a mixture of the locomotive exhaust and the generator exhaust,
• direct the output gas to the atmosphere through the second outlet, or
• direct a first portion of the output gas to the aftertreatment system through the first outlet and a second portion of the output gas to the atmosphere through the second outlet.