What is a Genset locomotive?
The term genset, aka generator set, refers to the type of engines used to provide power to the wheels of the locomotive. Where a conventional locomotive would use one large (typically 1,500 hp to 3,000+ hp) diesel electric engine, the genset uses one to three smaller, modern, ultra-low emissions, diesel electric engines to provide the power. A computer controls this set of smaller engines for maximum efficiency — starting and stopping each engine as needed for the power required.
More efficient by design
Genset locomotives are also equipped with advanced control logic that increases tractive effort by about 15% tightly controlling the wheel RPM and ground speed. The improvement in tractive effort further reduces the need for additional horsepower. The long-term fuel savings from a genset, when compared to a conventional locomotive, can be quite remarkable. Most genset locomotives are programmed to shutdown after the locomotive has not moved for five minutes, thus greatly reducing idle time. Start times for the genset are also much shorter than a conventional locomotive. A genset can be re-started at the push of a button, while the conventional locomotive engine has a lengthy 30 minute startup process.
The engines used in modern gensets emit 80+% less NOx from the fuel that is burned. Further, because they are more fuel efficient, they reduce the CO2 emissions dramatically. Each gallon of diesel that is burned yields 22.4 lbs of CO2. Thus, if a genset locomotive replaces a conventional diesel locomotive, the 50% fuel savings will often generate over 250,000 lbs less CO2. The lower fuel consumption of a genset greatly reduces the NOx emissions and will usually meet EPA Tier 3 emission standards for diesel powered locomotives. This is why genset locomotives are considered "green and clean."
Gensets do cost more than standard locomotives, however they meet more stringent EPA standards and the fuel savings make them a great choice for most yard switching applications.