At a time when highways are clogged and fuel reserves are strained, a machine that moves goods by dozens of thousands of tons represents a miracle technology that arrives not a moment too soon. It’s the futuristic freight train.
Trains are the cleanest way to move massive amounts of freight long distances. In 2005 General Electric cut fuel consumption by 5% and emissions by 40% compared to locomotives built just a year earlier with its Evolution diesel engines locomotives.
Not content to rest on their laurels, early this year GE unveiled a hybrid diesel-electric locomotive prototype at its Ecomagination event in Los Angeles. The locomotive uses a set of sodium nickel chloride (Na-NiCl2) batteries to capture and store energy dissipated during dynamic braking as well as an on-board fuel optimizer system.
The new design will reduce emissions by 50 percent and fuel usage by 15 percent compared to a conventional diesel-electric locomotive. The lead-free rechargeable batteries will be charged during regenerative braking mode — just like a hybrid car — and provide an additional 2,000 horsepower when needed.
The hybrid battery system for a locomotive needs to offer both high energy and high power. GE’s hybrid prototype has a power/energy (P/E) ratio of about two, a definite improvement to previous and rival prototypes.
Thought other variants of NiMH were considered according to GE, only the sodium nickel chloride batteries passed all the requirements for the system given the application demands, which included relative weight, relative volume, cooling medium, battery management, cooling impact on size and weight and reliability. The battery modules are environmentally sealed, thermally insulated, air-cooled, and operate at 300°C.
It’s been estimated that if every locomotive in North America could operate as the hybrid locomotive, railroads could achieve fuel savings of $245 million a year. Well it looks like not to be outdone by hybrid cars, railroad locomotives are in the run for their money, oops, alternative energy. But considering the fact that roughly 42 percent of all U.S. freight moves by train ( 5 billion ton-miles per day on 140,000 miles of track) and takes about a third as much fuel to move a ton of freight by rail as by truck, it’s the best alternative by large.
