University of California Transportation Center

The concept of the fuel cell traces its roots all the way back to William Grove’s famous experiments on water electrolysis in 1839, but the commercialization history of fuel cell technologies remains rather limited over 150 years later. Throughout the later part of the 19th and early part of the 20th centuries, attempts were made to develop fuel cells that could directly convert coal or some other carbon material into electricity, but these attempts were unsuccessful because scientific knowledge of material properties and electrochemistry was lacking. The first fuel cell capable of producing significant quantities of electricity was developed by Francis Bacon in 1932. This system used an alkaline electrolyte and nickel electrodes to produce electricity using hydrogen and oxygen. By 1952, Bacon had produced a 5kW system, and this provided much of the basis for further work on fuel cells in the 1950s and 1960s.

Fuel cell development received a boost in the late 1950s, when the National Aeronautic and Space Administration (NASA) determined that fuel cell technology was the most promising option for producing electricity in space in a compact and safe fashion. Nuclear power was considered too dangerous, batteries were too heavy, and solar power was too cumbersome. NASA eventually funded over 200 research contracts for fuel cell technology, and used both alkaline and proton-exchange membrane fuel cells (PEMFCs) in the Apollo, Gemini, and space shuttle programs. The Gemini program utilized 1 kW PEMFC units from 1965 to 1966, while 1.5 kW alkaline fuel cell (AFC) units were used in the Apollo program from 1968 to 1972. More recently, three 12kW AFC units have been used for at least 87 missions with 65 000 h flight time in the space shuttle Orbiter.[1] Altogether more than 100 manned space flights have been made by the US, totaling over 90 000 h of operating time, and all of these have used fuel cell systems developed by the United Technologies Corporation (UTC) of Windsor, CT.

The experience of UTC and its International Fuel Cells (IFC) unit with fuel cells for the space program led to the development of the first truly commercial fuel cell system, the PC25 phosphoric acid fuel cell (PAFC) product. This stationary fuel cell generating system, now in its third generation design, produces electricity from natural gas that is reformed into a hydrogen-rich gas stream before being supplied to the fuel cell stack. PC25s were first manufactured by IFC’s ONSI division in 1991, and approximately 200 of these 200kW fuel cell systems have now been purchased and deployed throughout the US and in other countries. Many of these systems were either procured under a US Department of Defense (DOD) fuel cell purchase program, where about 30 units were purchased and operated at US DOD facilities, or through a $1000kW−1 fuel cell purchase subsidy program also administered through the US DOD.[2]

For motor vehicle applications, General Motors has the longest history among major automakers, having experimented with fuel cell technology in the 1960s and having demonstrated the world’s first drivable fuel cell passenger vehicle in 1966. General Motors designed this vehicle, called the “Electrovan”, with liquid hydrogen and oxygen fuel tanks, and it achieved a range of 150 miles and a top speed of 70 miles h−1. The Electrovan program demonstrated General Motors’ early interest in developing fuel cell vehicles for commercial use, but it also uncovered the several obstacles that then became the focus of research and development. These included the needs for improved electronics, breakthroughs in electrochemistry, and new fuel cell stack and system materials.[3]

During the decade of the 1990s, fuel cells experienced an intense phase of research and development that led to the formation of many new companies and the establishment of new divisions within established companies, and a complex series of corporate mergers and re-organizations. Many different companies are now planning to commercialize several different fuel cell technologies for a wide range of markets. These fuel cell technologies include the PEMFC, AFC, and PAFC technologies mentioned above, but also higher temperature solid-oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC) types. A variation of the PEMFC can also use methanol directly, without first reforming it into hydrogen; it is known as a direct-methanol fuel cell (DMFC). There also is an interesting class of metal/air fuel cells that could also be considered “mechanically recharged” batteries, and that may be attractive for certain niche applications.

Fuel cells are currently being developed for the following applications:

• power for portable electronic devices (5–50W)

• power for remote telecommunications applications

(100W–1 kW)

• power for construction and outdoor recreational uses

(1–3 kW)

• auxiliary power units for cars and trucks, and motive

power for scooters (3–5 kW)

• stationary power generation (1 kW–50MW)

• electric passenger car, utility vehicle, and bus power systems (20kW–250 kW).

Some fuel cell companies are focusing on a single fuel cell type and application combination, while other companies are investigating more than one fuel cell technology and various potential applications. The following sections of this chapter briefly describe the current state of fuel cell industries for the stationary power and transportation markets, some of the commercialization plans for these two sectors, and additional thoughts about prospects for market commercialization of fuel cell technology. We do not discuss in detail the prospects for fuel cell for portable electronic devices, since this application is rather distinct and still at a relatively early stage of development.