General Electric (GE) Transportation Rail is developing a hybrid 4,400-horsepower diesel-electric locomotive designed to store electric energy in a battery bank. The new design will reduce emissions by 50 percent and fuel usage by 15 percent compared to a conventional diesel-electric locomotive. The road unit will feature lead-free rechargeable batteries, which will provide the locomotive with an additional 2,000 horsepower when needed. The batteries will be charged during regenerative braking mode, just like a hybrid car.
“GE’s hybrid locomotive is being designed to reduce carbon dioxide emissions over its lifetime equal to taking 2,600 cars off the road for a year and emitting half as much nitrogen oxide as locomotives built 20 years ago,” GE officials said.
According to GE, the energy used to brake a 207-ton locomotive during the course of one year is enough to power 160 households for that year. If every locomotive in North America could operate as efficiently as the hybrid locomotive, railroads could achieve fuel savings of $245 million a year.
Virtually all American freight locomotives are hybrids, in which a diesel engine turns an alternator that feeds current to electric traction motors located between the locomotive’s wheels. Locomotives supplement their airbrakes with dynamic braking, or regenerative braking, by using the traction motors as generators. Normally, the current generated by dynamic braking is dissipated as heat through resistor grids at the top of the locomotive. However, the hybrid locomotive will use the electric current from dynamic braking to charge a battery bank. GE engineers presently are trying to determine how to harness a flow of electricity that normal batteries cannot handle.