John McCain's campaign statement last month that as U.S. president he would offer a $300 million cash prize to the inventor who can develop a battery pack that has “the size, capacity, cost and power to leapfrog commercially available plug-in hybrids or electric cars” briefly put fuel cells back in the public consciousness.
While fuel cells are years away from widespread use, their potential to one day offer an insanely efficient, clean alternative to conventional power sources makes them a worthy subject for Electrical Wholesaling's continuing series of articles on green power, which to date has covered photovoltaics (May 2008, page 36) wind power (June 2008, page 44); and offered a broad overview of the green power market (April 2008, page 26). They don't produce any noxious carbon emissions and could power anything from your cell phone to the car you drive to work.
Fuel cells generate power by chemical reaction, and the beauty of what makes them work is that they don't need any hard-to-find chemical compounds to operate. In what's generally considered to be one of the most promising types of fuel cells (polymer exchange membrane fuel cells), the chemical reaction that ultimately produces power relies on hydrogen and oxygen. In this type of fuel cell, the power is produced when hydrogen is exposed to a platinum-covered anode and oxygen is forced into the cathode to create an electrical charge that's carried out of the fuel cell on an external circuit to power motors, batteries and other loads. In this technology, individual fuel cells are combined together in “stacks” to produce the necessary amount of voltage. See www.howstuffworks.com for more technical details.
Interestingly, fuel cells have actually been around since 1839. Sir William Grove knew (even back then!) that water could be split into hydrogen and oxygen through electrolysis by sending an electric current through it. According to www.howstuffworks.com, he reversed that process and produced electricity and water in a primitive fuel cell that he called a gas voltaic battery. While fuel cells have been around in one form or another for 169 years, it's still a challenge to figure out a way to get them to produce cost-competitive power. NASA used them extensively in the Gemini and Apollo missions, but cost-effective applications back on earth have been tough to find so far. www.fuelcells101.com says fuel cells currently produce energy at 10 times the cost of fossil fuels.
The components in fuel cells, including the platinum mentioned in the example above, are expensive and the chemical reactions that create the power in fuel cells can be quite corrosive, which is hard on a fuel cell's electrodes and membranes. Government-funded research laboratories like the National Renewables Energy Laboratory (NREL), Golden, Colo., and private companies are spending much of their time developing more durable and less expensive fuel-cell components.
Despite their expense, fuel cells do work and are used in some interesting applications around the world. According to Fuel Cells 2000, Washington, D.C., more than 2,500 fuel cell systems worldwide provide either primary or back-up power for offices, hotels, hospitals, nursing homes, schools and utilities. When used for primary power, it's usually in applications miles away from the power grid that need an independent power source. Fuel Cells 2000 says fuel cells provide power that's reliable 99.999 percent of the time for 1kW to 5kW telecom sites such as cell towers or switching stations inaccessible to the power grid. This organization says fuel cells have also shown that they can power cell phones for 30 days without recharging and can run laptops for 20 hours.
Fuel-cell powered cars may be the first application of this technology that the general public will see. Buses powered by fuel cells have been operating for a few years in limited applications, and American Honda Motor Co. recently announced that five customers in the United States will get the company's new fuel cell vehicle, the FCX Clarity car, which gets the equivalent of 74 mph and has a range of 280 miles. The customers, including actress Jamie Lee Curtis, will rely on a network of hydrogen refueling stations at Honda dealerships in Southern California. One of the drawbacks with fuel cell vehicles is that they are equipped with tanks of compressed hydrogen and that once the hydrogen is spent, the tank needs to be refilled. Researchers are experimenting with other hydrogen-based fuel sources, such as methane gas and methanol. They hope to develop new processes that would separate the hydrogen out of these chemical compounds to power fuel cells but not emit any harmful gases or other byproducts.
Don't expect fuel cells to change your life in the near future because of their high cost. But their potential to power applications as small as a cell phone or power tool or as large as an entire office building, bus or car without producing harmful emissions or utilizing scarce resources, may one day make them a viable source of power and help lessen the world's dependence on oil.
If You Want to Learn More
www.howstuffworks.com offers a clear technical explanation about how fuel cells work.
Fuel Cells 2000, Washington, D.C., tracks technical developments in fuel cells and offers truckloads of information at www.fuelcells.org.
The U.S. Department of Energy's Hydrogen Program explains fuel cell technology at www.hydrogen.energy.gov.
The National Hydrogen Association, Washington, D.C., promotes the use of fuel cells and other hydrogen-related technologies at www.hydrogenassociation.org.
The National Renewables Energy Laboratory (NREL), Golden, Colo., explores the use of earth-friendly technologies such as fuel cells, photovoltaics and wind power.
How You May One Day Use Fuel Cells
Fuel cells may one day become commercially viable for widespread use in vehicles, primary or backup power and in consumer electronics. Here's a brief list of existing and potential applications.
- Primary power
- Backup power
- Laptop computers
- Smoke detectors
- Power tools