BNSF Railway and Vehicle Projects Develop Experimental Hydrogen Fuel-Cell Switch Locomotive; Locomotive-to-Grid Application Explored
|Drawing of the fuel-cell hybrid locomotive. Click to enlarge.|
BNSF Railway Company and Vehicle Projects LLC, a developer of large fuel-cell vehicles such as mine loaders and mine locomotives, are leading a project consortium to develop an experimental hydrogen fuel-cell hybrid switch locomotive.
The vehicle platform is based on the Green Goat diesel-battery hybrid switcher, and the powerplant and hydrogen storage are based on the Citaro hydrogen fuel-cell transit bus (earlier post). The goal of the project is to demonstrate reduced air and noise pollution in urban rail applications, including yard switching; and to demonstrate the fuel-cell switchers for use as a mobile backup power source (“locomotive-to-grid”, or “power-to-grid”) for military bases and civilian disaster relief efforts.
Field testing is scheduled to begin later this year, with the LA Basin serving as the location for reduced emissions testing and Hill AFB in Utah serving as the location for the backup power application.
As a nation, two widely-accepted issues are global climate change and energy insecurity, which have a common factor—oil. The world burns millions of barrels of oil for energy, and the waste carbon is then emitted to the atmosphere. Because they don't rely on oil as a fuel source, fuel cells solve these two issues. Along with our principal partners, BNSF and the US Army, we at Vehicle Projects are developing proof-of-concept hydrogen fuel cell vehicles that are leading the way to this new technology.—Arnold Miller, president, Vehicle Projects LLC
|Yard switcher duty cycle. Click to enlarge.|
The project team is replacing the 200kW diesel prime mover in the Green Goat switcher with a 250kW fuel cell powerplant—based on the powerplant of the Citaro bus—comprising two 125 kW modules. The auxiliary lead-acid traction battery allows transients in excess of 1 MW. The electrically driven rear traction-motor cooling fan and brake air compressor of the Green Goat will remain in place beside the prime mover.
For the power-to-grid application, an off-board power converter will convert the 600-850 VDC output of the fuel cell powerplant to the three-phase AC power of the military-base grid. The hybrid locomotive can provide 250 kW of power on a continuous basis but can provide power surges in excess of 1 MW. Its low acoustic noise and vibration are essential features of its practicality in power-to-grid applications.
Fourteen carbon-fiber composite tanks, located above the traction battery, store a total of 70 kg of compressed hydrogen at 350 bar. Vehicle Projects conducted a safety analysis showing that compressed hydrogen on the roof is essentially as safe as reversible metal-hydride storage in the undercarriage bay (i.e., replacing the diesel fuel tank); the high weight of metal-hydride storage precludes the roof location.
Locomotives require a fixed operating weight. Because the combined weights of the fuel cell powerplant and carbon-fiber hydrogen storage system are substantially lighter than the diesel genset and diesel fuel tank they replace, a steel-plate ballast of approximately 1.0 m3 volume will be placed in the undercarriage bay.
The operating time of the fuel cell-hybrid switcher between refueling operations depends on the duty cycle. Under the most demanding duty cycles, one could expect an operating interval as short as one day, i.e., refueling on a daily basis; in less demanding yards, the interval may be 3-5 days. A major factor in the operating interval is the amount of idle time in the duty cycle.
|Project Consortium Members|
|American Superconductor (pending)||Power electronics|
|Ballard Power Systems||Fuel cell stack modules|
|BNSF Railway Company||Industry funding; fabrication; vehicle integration; testing; yard demo|
|Defense Gen. & Rail Equipment Center (DGRC)||Advising on military applications; power-to-grid demonstration|
|Dynetek Industries||Hydrogen storage|
|RailPower Hybrid Technologies||Manufacture of Green Goat Platform|
|Transportation Technologies Center, Inc.||Railyway safety regulations|
|University of Nevada-Reno||Refueling systems design|
|US Army (NAC)||Project oversight|
|Vehicle Projects LLC||Engineering design; project management|
|Washington Safety Management Solutions||Safety Analysis|
Fuel Cell Hybrid Switcher Project (Fuelcell Propulsion)