East Japan Railway Company has developed the world's first prototype of a hybrid diesel-electric rail car, called "NE Train (New Energy Train)," and is planning to start test runs.
    The company has been working to develop rail cars that have lower environmental impacts through innovation of the propulsion system, by incorporating hybrid technology and fuel cell technology. The test run will be the first step in evaluating feasibility and energy efficiency of the new system.
    The prototype is a single rail car with an onboard engine and employs a series-hybrid system with the future potential of being adapted to fuel-cell-driven rail cars.
    The engine serves as the mechanical power source and is arranged in a series configuration with the electrical power source. The diesel engine drives the generator, and the generator supplies electricity to the electric motors that drive the ! wheels. In the future, this system can be adapted to a fuel cell system by simply replacing the engine and the generator with fuel cell stacks.
    The motor is powered solely by electricity when starting, and the diesel engine starts during acceleration, generating additional electricity. This electricity plus the electricity stored in the battery drive the motors. A regenerative braking system also charges the battery when braking, thus enabling the engine to be stopped while the train is arriving at and departing from the station.
    By optimizing the regenerative breaking system, the company hopes to increase energy efficiency by approximately 20 percent compared to the conventional rail car "Series Ki-Ha 110." The company also aims to halve the emissions of nitrogen oxide and particulate matter by using a cutting-edge low-emission diesel engine for generation, and by using the hybrid system.