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Small fuel cells can provide electrical power for many applications including lighting, communications, navigation, computation and entertainment. A fuel cell combines aspects of an engine and a battery. Like an engine, a fuel cell will run as long as fuel (hydrogen) is supplied. Like a battery, it produces electricity by electrochemical reactions.

A fuel cell, like a battery, has an anode side and a cathode side with an electrode (the exchange membrane) in between. A proton-exchange membrane (PEM) fuel cell works like this:

Hydrogen is supplied to the anode where it breaks apart into protons and electrons. The electrode conducts protons but not electrons. The protons flow through the electrode while the electrons travel through the external circuit and provide electrical power. The electrons and protons are reunited at the cathode and combine with oxygen from the air to produce water. Fuel cell stacks are created by layering the cells on top of each other, allowing for more power to be generated. The water evaporates from the fuel cell stack into the surrounding air.

No pollution is emitted by a PEM fuel cell running on hydrogen; only electricity, heat and pure water are produced. In addition, fuel cell construction materials are benign to the environment.

Fuel cells are not new -- they were invented by Sir William R. Grove in 1839. However, fuel cells capable of producing significant power were not developed until 1959 when Francis T. Bacon introduced an alkaline fuel cell capable of producing 5,000 watts (5kW). Bacon's fuel cell served as a starting point for the fuel cells developed by NASA and used to provide electrical power on both the Gemini and Apollo spacecraft. As a result of NASA's work, fuel cells were shown to be capable of efficient and reliable electrical power generation.

Unfortunately, the fuel cells of that era were also inherently expensive (mostly due to the large amount of platinum needed to manufacture the fuel cells). In the late 1980s and early 1990s, significant reductions in the amount of platinum needed for PEM fuel cells were obtained. Much of this work was performed at Los Alamos National Laboratory (LANL), a government (U.S. Department of Energy) owned facility located in Los Alamos, New Mexico.

In 1996 and 1997, Mahlon S. Wilson of LANL developed a smaller, simpler class of fuel cells that relies on ambient air pressure for oxygen and on its own water generation for humidification (instead of pumps and fans, which are needed in other types of fuel cell technologies). Mr. Wilson improved PEM technology by designing a round fuel cell stack in which hydrogen is delivered through a central tube that also houses the bolt that holds the stack assembly together. This design is smaller, lighter and easier to fabricate than rectangular PEM fuel cells, and it is also more efficient because it leaves the entire exposed surface of the cell open for ambient oxygen intake and heat dissipation. It also more efficiently retains water, the reaction product, to prevent dehydration of the cell. The circular fuel cell can be packaged as a D-cell battery-sized stack combined with a metal hydride canister that will last more than three times as long as a comparably sized pack of nickel-cadmium batteries. The cells also can be easily ganged together for higher power applications.

In 1998, DCH Technology, Inc. successfully negotiated a Cooperative Research and Development Agreement (CRADA) and exclusive license agreement with LANL for the "air-breathing proton-exchange membrane (PEM) fuel cell", patented by Mr. Wilson, LANL and the United States Department of Energy.

THE DCH / LANL FUEL CELL DESIGN
A commercially successful low power portable fuel cell should:

• Be simple, quiet and reliable
  
• Have relatively high energy densities
  
• Require no active cooling or humidification
  
• Operate at low stack hydrogen pressure
  
• Not require air or water pressurization or forced flow
  
• Not be sensitive to orientation

These requirements have been met by a design developed by DCH Technology based on the patents licensed from LANL.

Hydrogen is supplied through a central manifold and flows radially outward over the one side of the membranes. Oxygen from the air diffuses into the stack from the periphery and flows radially inward over the other side of the membranes and diffuses outward to the surface of the stack where it evaporates into the atmosphere.

This configuration limits the ability of the water to escape easily from the stack. This prevents the PEMs from drying out, even at relatively high operating temperatures and current densities, resulting in a stack that is inherently stable and self-regulating.

The components are symmetrical so part fabrication is amenable to mass production. The stack is quiet, compact, rugged and lightweight.

SYSTEM OPERATION

A demonstration of the DCH fuel cell is shown below. This demonstration took place at the National Hydrogen Association conference in April 1999. Later, it was displayed in Washington, DC for several congressmen and staffers on Capitol Hill.

Two fuel cells are shown powering a fluorescent light, a small CD player and a small television. In this instance, hydrogen is supplied from two metal hydride storage canisters (the small canister in the lower right corner of the photo and the taller canister at the center bottom of the photo) and DC to DC converters (in the metal box at the center of the photo) are used to step down the fuel cell output voltage to run the various appliances.

It is possible to combine stacks in essentially any desired series and parallel configuration to achieve the desired voltage and current.

This is a simple, clean, quiet and reliable energy device for low power needs. We believe it is an efficient and effective power source for many portable electric power requirements.

FUEL CELL MARKETS AND BARRIERS
There are a number of small, portable fuel cells in development at various companies for low power needs. Anywhere low power is required, a fuel cell could be the ultimate clean energy answer. These might include residences, emergency lighting and power, camping equipment, battery recharging and any number of other applications.

The biggest barriers to the technologies today are affordability and fuel issues. Companies need to remember that the promise of clean energy alone will not sell the fuel cell product to most customers. The potential customer will be concerned with price and value. The customer must be able to afford to pay for the product and perceive that he or she is getting value for her or his money in terms of reliability and performance. In addition, the availability of fuel for the product is an issue. People cannot visit their local Wal-Mart or gas station and purchase hydrogen to run their fuel cells. Because of these limitations, most current customers are in research and government.

DCH is working closely with leading-edge companies to tear down the barriers. While there certainly are no guarantees, we believe that we are on a path to overcoming the barriers to full commercialization of fuel cell technologies for low power needs and we encourage other companies to expedite the transition of the fuel cell technology from the lab to the business world.

DCH FUEL CELL FACILITY
DCH Technology recently expanded its fuel cell facility near Madison, WI to prepare for production of the devices. Initial pre-production of the fuel cell units could begin as early as October 1999 with full-scale production commencing the following year.

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