Fuel Cells Offer Different
Advantages, Disadvantages"> Meanwhile, fuel cells also present an alternative source of power for notebook PCs. Numerous manufacturers are currently working on creating fuel cells that can be used with notebooks. The first fuel cells, which are hitting the market now in small quantities from companies such as UltraCell, will be used as external power sources, becoming a portable electric outlet of sorts, for notebooks used by military units or scientists who currently have to carry numerous battery packs, said Ted Prescop, senior applications engineer at UltraCell, in Livermore, Calif.UltraCells first fuel cell, a 2.2-pound unit that costs about $1,000 and uses 1-liter methanol fuel cartridges, is sampling to some clients now and is scheduled to go into wider production in early 2007. The unit will serve as a universal power supply for several different notebook brands, he said. Right now, "Fuel cells dont make sense for short run-times. It only makes sense if youre going to be running for a couple of days," he said. "Its much easier to bring along extra fuel than extra batteries." Over time, fuel cells and fuel cartridges will come down in price and size, Prescop predicted, making them more consumer-friendly. UltraCells second-generation fuel cell, which he said is being developed in the companys labs now, will be attachable to the back of a notebook and will work in concert with a notebooks battery. The cells half-liter fuel cartridge may stick out slightly, he said, but isnt likely to be more obtrusive than one of todays extended run-time battery packs. Travelers using the product could leave their AC adapters behind. A third-generation integrated fuel cell, which could be built into a notebooks chassis, should arrive within about five years, Prescop said. But even with a fuel cell present, a notebook is still likely to use a battery, given that fuel cells tend to deliver a constant rate of power, while notebooks needs vary. The companion battery, which is likely to be smaller than those used today, would also provide energy to start the fuel cell. However, its main purpose would be to act as a gas tank of sorts, storing energy from the fuel cell and then supplying it to the notebook according to the machines needs. Theoretically, a small fuel cell with a 200-cubic-centimeter cartridge could meet most peoples needs, Prescop said. A fuel cell that provided 180 watt-hours of power per 200cc cartridge would supply enough juice to run a 10-watt ultraportable notebook for about 18 hours, for example. But, despite the advances that are possible for fuel cells or the more immediate potential for silver-zincs ability to exceed the energy density of todays lithium-ion batteries, any potential replacement technology will still face a difficult road. Given that PC makers such as HP operate on thin margins, costsranging from the costs involved in redesigning battery circuitry to the potential price premiums of new battery packs themselvesare all critical considerations. "From a competitive standpoint, from a dollars-per-watt-hour perspective, will [zinc-silver] ever approach where lithium-ion is?" Wozniak asked. For now, PC makers such as HP are likely to prefer to simply continue working to improve the safety and energy capacity of lithium-ion technology, he indicated. Efforts are already afoot to do both. Sanyo, Sony and Panasonic (of Matsushita Electrical Industrial Co.), the worlds top battery makers, continue to work to squeeze more out of lithium-ion technology. Intel and Panasonic, for example, have been collaborating to develop new lithium-ion cell designs that use nickel to increase their energy density. (An Intel representative said on Oct. 4 that company officials were unavailable to comment on the technology, while Panasonic officials in New Jersey did not return a call requesting more information on the battery technology.) Companies are also exploring other approaches to lithium-ion technology, including one called lithium-ion phosphate. Valence Technology, of Austin, Texas, one company that is developing a lithium-ion phosphate technology, has said the approach is safer because its technology uses different types of materials, including a phosphate-based cathode, which are not prone to thermal runaway or overheating and will not burn. However, none of the advances are without trade-offs, Wozniak said. "Lithium-ion phosphate has been around a while and it is a safer chemistry for no other reason than [that] its a lower-energy chemistry," he said. At about 1.6 amp-hours, versus the 2.6 to 2.9 amp-hour ratings of current and near-future lithium-ion battery cells, "You need a battery thats half again as big to get the same amount of power. Its not well-suited for portable applications, really." Thus, PC makers have begun working on ways to improve the safety of lithium-ion batteries by addressing the way the cells are made. The OEM Critical Components Committee of the electronics products standards body IPC recently met to begin work on a set of standards for manufacturing and testing lithium-ion cells. Its aim is to raise the bar for battery cell makers and therefore make it less likely for contaminants to enter the cells during manufacturing. Others are doing work individually. HP has been working with a company called Boston-Power, Wozniak said. He said Boston-Power is formulating a revised lithium-ion battery chemistry that can lengthen battery packs life cycles by roughly tripling the number of charge/discharge cycles they can endure before their ability to store energy degrades. However, ultimately, "You cant sell safety," he said. "You cant say, Heres my regular battery and heres my safer one. If you come up with a technology thats safer, it has to be licensed across the industry to have an impact." Check out eWEEK.coms for the latest news in desktop and notebook computing.
"The main benefit to a fuel cell is you can get a lot more energy per pound than you can with a battery," Prescop said. "What a lot of fuel cell companies are struggling with is how to make a small system thats also affordable. Its going to take a few years to get down in price to where average laptop users are going to consider [a fuel cell] as an alternative to batteries."