Articles
“Hydrogen tube vehicle for supersonic transport: 2. Speed and energy.” View the abstract >

This paper, second in a series on the scientific foundations of the supersonic tube vehicle, tests the hypothesis that the STV will be simultaneously fast and energy efficient by comparing its predicted speed and energy consumption with that of four long-haul passenger transport modes: road, rail, maglev, and air. Consistent with the hypothesis, the concept vehicle is both the fastest and lowest energy consuming mode. In theory, the vehicle can cruise at Mach 2.8 while consuming less than half the energy per passenger of a Boeing 747 at a cruise speed of Mach 0.81.

A. R. Miller, “Hydrogen tube vehicle for supersonic transport: 2. Speed and energy.”International Journal of Hydrogen Energy, 35:11 (2010) 5745-5753.

“Rail Vehicles: Fuel Cells.” A. R. Miller, “Rail Vehicles: Fuel Cells.” In: Encyclopedia of Electrochemical Power Sources, Vol. 1. Amsterdam: Elsevier; 2009. pp. 313-322. Juergen Garche, Chris Dyer, Patrick Moseley, Zempachi Ogumi, David Rand and Bruno Scrosati, editors.

“Hydrogen tube vehicle for supersonic transport: Analysis of the concept.” View the abstract >

The first in the supersonic tube vehicle paper series, this paper analyzes the feasibility of the concept of a hydrogen tube vehicle for supersonic transport. It proposes a conceptual design – power source, propulsion, levitation, and guidance – and then analyzes its feasibility – power and energy requirements, vehicle packaging, levitation by gas bearings, and safety.

A. R. Miller, “Hydrogen tube vehicle for supersonic transport: Analysis of the concept.” International Journal of Hydrogen Energy, 33:8 (2008) 1995-2006.

“System design of a large fuel cell hybrid locomotive.” View the abstract >

Published in the Journal of Power Sources, this paper addresses the design of the prototype hydrogen-fueled fuel cell-battery hybrid switcher locomotive for urban and military-base rail applications. Several technical challenges not found in the development of smaller vehicles arise when designing and developing such a large fuel cell vehicle. Weight, center of gravity, packaging, and safety were design factors leading to, among other features, the roof location of the lightweight 350-bar compressed hydrogen storage system. Harsh operating conditions, especially shock loads during coupling to railcars, require component mounting systems capable of absorbing high energy. Vehicle scale-up by increasing mass, density, or power presents new challenges primarily related to issues of system layout, hydrogen storage, heat transfer, and shock loads.

A. R. Miller, K. S. Hess, D. L. Barnes, and T. L. Erickson, “System design of a large fuel cell hybrid locomotive.” Journal of Power Sources, 173 (2007) 935-942.

“Comparison of practical hydrogen-storage volumetric densities” View the abstract >

Presented at the NHA Annual Hydrogen Conference 2007, and later published in the proceedings, this paper reports the results of feasibility studies of locomotive onboard fuel storage as part of our fuelcell locomotive program, commencing in May 2003. Storage of hydrogen onboard the vehicle is a greater technical challenge than producing power from a fuelcell. Technically mature methods of storage for large, high-power vehicles such as locomotives include (1) direct storage of hydrogen as a compressed gas, (2) direct storage as a liquid, (3) direct storage as a reversible metal hydride, (4) onboard chemical transformation to hydrogen of a carbon-based feedstock such as a hydrocarbon or alcohol, and (5) physical dissociation of liquid ammonia to hydrogen.

A. R. Miller, K. S. Hess, and D. L. Barnes, “Comparison of practical hydrogen-storage volumetric densities.” In: Proceedings of the NHA Annual Hydrogen Conference San Antonio, Texas, 19-22 March 2007.
“Analysis of fuelcell hybrid locomotives.” View the abstract >

Published in the Journal of Power Sources, this paper analyzes a part of the feasibility and conceptual-design analysis of the 109 t, 1.2 MW road-switcher locomotive for commercial and military railway applications. A study has been made of the potential benefits of a hybrid power plant in which fuel cells comprise the prime mover and a battery or flywheel provides auxiliary power. The potential benefits of a hybrid power plant are: (i) enhancement of transient power and hence tractive effort; (ii) regenerative braking; (iii) reduction of capital cost.

A. R. Miller, J. Peters, B. Smith, and O.A. Velev, “Analysis of fuelcell hybrid locomotives.” Journal of Power Sources, 157:2 (July 2006) 855-861.

“Least-cost hybridity analysis of industrial fuel cell vehicles.” View the abstract >

Because fuelcells cost more than batteries, intuitively it would seem that the least-cost configuration of a fuelcell-battery hybrid would have the fuelcell operate continuously at the mean power of the duty cycle. This generally, however, is not correct. While batteries are less expensive on a per kW basis, an acceptable cycle life for an industrial vehicle requires a shallow depth of discharge and therefore a battery oversized by as much as a factor of 20. When fuelcell capital cost, oversized battery capital cost, and battery cycle life are simultaneously optimized, the least-cost configuration has the fuelcell operate above the mean power.

A. R. Miller, “Least-cost hybridity analysis of industrial fuel cell vehicles.” European Fuel Cell News, Volume 7, January 2001.

“Tunneling and mining applications of fuel cell vehicles” View the abstract >

This paper introduces underground vehicle applications. Underground vehicle applications — tunneling and mining — may be the first fuel cell vehicle markets that succeed solely on economic merit. Providing traction power in these enclosed, highly regulated workplaces is a difficult challenge, and the inadequacies of conventional power are the basis of economic stress in the industries. Clean, safe and productive fuel cell vehicles, while higher in capital cost, offer cost offsets that can make them the first commercially successful products. The Locomotive Project of the Fuelcell Propulsion Institute is developing and testing the world's first fuel cell-powered underground vehicle, a mine locomotive. The 25-month project involves more than 20 international partners, including mining companies, mine vehicle companies, mine regulators, organised labour and national laboratories, and is internationally funded by two governments and the mining industry.

A. R. Miller, “Tunneling and mining applications of fuel cell vehicles.” In: Fuel Cells Bulletin, July 2000, pp. 5 - 9.