Beyond batteries: Long-lasting fuel cells are the future
- 18 July, 2008 08:33
Whether you're talking on a mobile phone, listening to tunes on a media player or typing on a notebook, it's a good bet that the device's battery won't last as long as you'd like. However, that will change over the next few years, as fuel cells designed to power mobile gear start to become common.
In particular, direct methanol fuel cells (DMFC) will deliver as much as 10 hours of power using a thimbleful of methanol -- that's two to three times the life of current laptop batteries. Better still, when a fuel cell runs out of power, you don't have to find an AC outlet and wait for a battery to recharge. Rather than taking the plug-and-wait approach, you'll either refill the tank from a larger canister or simply insert a new, full reservoir. You can run your mobile gear as long as you have methanol to satisfy the fuel cell's thirst.
For the past decade, fuel cells have seemed to be tantalizingly close to commercialization, but they never quite made it to market. Finally, they really do appear ready, with several major manufacturers of batteries, fuel cells and mobile devices saying that 2009 will be the start of the fuel-cell era.
This could change how we think about mobility, freeing us from the tyranny of short-lived batteries and the need to find an electric outlet. In other words: Road warriors, rejoice! You have nothing to lose but your batteries.
Here's the lowdown on this promising technology, how it will affect your mobile lifestyle and when you likely will be able to use it.
"The long-term vision is that anywhere people are using batteries today, they can be replaced by fuel cells," explains Peng Lim, chief executive officer at MTI Micro Fuel Cells. MTI is working on internal and external fuel cells for powering mobile gear.
"The transition to fuel cells has already started, although it won't happen overnight," says Sara Bradford, principal consultant for the energy and power systems group at market analyst firm Frost & Sullivan, noting that the first external fuel-cell power packs are just hitting the market.
For instance, the Medis 24-7 Power Pack can pump out up to 5.5 volts of pure, clean power. At US$30, it should be good for about 30 hours of phone use, or double that for a media player. After that, a US$20 refill tank is all you'll need -- that tank will last another 60 hours.
This system isn't aimed at being a primary source of mobile power, but an alternative source of power for emergencies or if you're away from an electrical outlet for a long period of time. But at 6.5 ounces, it weighs as much as a smart phone.
The Medis system is an external add-on; the next step is refillable fuel cells built into mobile devices.
"Next year, look for a smart phone that has a fuel-cell option," says Sean Collins, vice president for business development at Toshiba America Electronic Components. While the engineering and marketing details haven't been worked out, Collins adds that several phone makers are looking to sell products with a traditional battery as well as an optional fuel cell that fits in the same space.
Further out on the horizon, the technology will get really interesting for road warriors, with mobile equipment designed for and fully powered by fuel cells. "In three to five years," Collins explains, "equipment that runs solely on fuel cells will hit the market."
Besides improving technology, another factor that should spur adoption of fuel cells is the Federal Aviation Administration (FAA). Today, fuel cells and methanol are big no-nos on planes, but that will change in October, when the FAA will start allowing travelers to bring fuel cells on board airliners along with two refills of methanol.
"You may not be able to bring your nail clipper on the plane," quips MTI's Lim, "but a fuel cell will be OK. This will be a big spur to the commercialization of fuel cell technology."
Because fuel cells will soon be able to go anywhere you go, sales are forecast to grow quickly. Frost & Sullivan's Bradford thinks that by 2012, 80 million micro fuel cells will be sold to power notebooks, mobile phones, media players and other portable devices. That's up from 1 million fuel cells shipped in 2007 and a projected 25 million fuel cells in 2010.
On the downside
While fuel cells are about ready to go, a few shortcomings remain.
"Fuel cells are great for providing constant power," adds MTI's Lim. "But they can't handle the peak power demand that's required by most electronic devices."
For example, when a mobile phone starts playing a streaming video, its power draw can rise from 2 watts to 5 watts in less than a second, overwhelming a fuel cell's output. As a result, the first generation of practical fuel cells will be hybrid designs that have a small lithium bridge battery to provide extra power for such situations.
When the bridge battery is out of juice, it will be recharged by the fuel cell, a process that will take time. During that time, performance of the device could be degraded.
One long-term solution to this problem is replacing the add-on battery with a capacitor that stores enough power to augment the fuel cell. In the shorter term, Sony recently showed a prototype hybrid fuel cell with a small lithium-ion battery. The fuel cell delivers a steady 3 watts of power, which is what a typical smart phone requires, with the battery filling in on an as-needed basis.
The package measures 1.2 by 2 in., or about the size of a cell-phone battery. It powered a handset displaying digital broadcast TV for 14 hours nonstop. Its fuel: one-third of an ounce of methanol.
Another problem, at least in the short term, is price: Fuel cells will cost more than traditional batteries at first. "They'll be more expensive compared to lithium batteries, but we expect that to change quickly," says MTI's Lim.
One reason prices are expected to drop is that fuel cells have require fewer parts than batteries, and those parts are easier to manufacture. And, of course, technology prices usually decrease as adoption increases. Lithium batteries, which first started being widely used about 13 years ago, are a perfect example of this trend.
"Back then, lithium batteries cost US$30 per cell," recalls Toshiba's Collins. A typical notebook battery uses between three and nine cells. "Today, they're about $3 a cell. We expect this cost curve to apply to fuel cells and expect products that will be competitively priced in the consumer electronics marketplace. The bottom line is that the time for fuel cells has arrived."
A glimpse of the (near) future
Fast-forward just a few years to a business traveler on her way to Asia with a notebook full of work to do. Before getting on the plane, she stops at an airport convenience store to buy two methanol refill cartridges for her notebook and stashes them in her bag.
On the 15-hour flight, she puts the finishing touches on her presentation, clears out a backlog of e-mails and writes a memo about a new product. Before settling down to watch a DVD or two, she gets a warning that her notebook's fuel cell is running low on fuel. After replacing its methanol tank with a fresh one, she enjoys a movie marathon for the rest of the flight without interruption. Such prolonged use of a laptop simply isn't possible today.
Says Frost & Sullivan's Bradford: "In 10 years, we'll probably look back and wonder how we put up with lithium batteries."