Toshiba boffins prep laptop fuel cell

(Just) small enough to be useful

Toshiba has figured out how to power a portable computer using fuel cell technology without the need for a power unit larger than the PC itself.

Toshiba's small form factor direct methanol fuel cell (aka DMFC) can operate for five hours, generating between 12W and 20W of power and is electrically compatible with existing Lithium-Ion rechargeable batteries. It's not yet the size of a typical notebook battery, but Tosh is working on it.

The fuel cell generates electricity as a by-product of a chemical reaction involving dilute methanol. Methanol can be produced easily and in vast quantities, so the fuel cell is widely seen as a very inexpensive alternative to batteries. And by generating electricity directly, it's arguably a greener technology too.

The principle behind fuel cells has been understood for some time. The problem has been generating sufficient energy to power what you want to power, and to do so with a unit that's conveniently sized for the application.

It's taken the motor industry years to develop a fuel cell capable of powering a car, for example. GM's HyWire is the first drive-by-wire car to be based on a fuel cell.

Similarly, Toshiba's DMFC is the first fuel cell to be small enough to potentially replace laptop batteries. The technology uses water produced by the fuel cell to dilute the methanol to the 3-6 per cent concentration required for the electricity generating reaction. The upshot: the methanol can be stored at a much higher concentration, requiring a much smaller (ten per cent) fuel tank. That means smaller, more practical cells.

Toshiba has also shrunk other key components, including the electronics needed to allow the host notebook to monitor and control power production so that none is wasted.

Toshiba will unveil a prototype DMFC at CeBit next week, but commercialisation of the technology is unlikely to take place until next year.

If it gets product out by then, Toshiba will probably be first to market. An Intel-funded start up, PolyFuel is working on direct methanol fuel cells for laptops. This delivers 150 watt hours hour battery capacity, three times greater than the best mobile PC batteries a day, but commercial product will take two-to-three years to get to market. And we understand German company Smart Fuel Cells will be showing a similar system to Toshiba's at CeBit. ®