Toshiba claims to have invented a small sized fuel cell capable of powering a laptop for five hours. (via slashdot). This is great, and I have written about it before.

Basically, though, a fuel cell is a battery that runs on liquid fuel. It contains a fuel tank, and a chemical process occurs in the cell that generates electricity by using up the fuel, which is normally methanol. When the battery runs out of fuel, you simply open the battery's fuel cap, pour in some more fuel, and bingo, another five hours. The advantages of this are that it will be possible to design fuel cell powered laptops that can run for many more hours than is presently the case, and (perhaps even more important) recharging the battery is quick and inexpensive. To refuel such a battery, you either carry a bottle of fuel with you, or when you run out you go into the nearest supermarket, newsagent, or office supplies store, and you buy a refill. This makes it possible for people to use their laptops for prolongued periods of time without lengthy sessions in which they have to plug them into mains electricity. This is so much better than the status quo that once these things are readily available, all laptops will have them within a very short period of time. (It may be that they become standard for mobile phones as well).

This is going to cause one more problem, however, which is that it is going to encourage people to carry around botles of methanol, which is highly inflammable. One of the chief places people are going to want to use laptops for prolongued periods of time is on aircraft. For obvious safety reasons, it is not normally permitted for passengers to carry bottles of methanol on aircraft with them. The 10% solution requiered by this fuel cell is probably not a great safety risk, but airlines are still not going to like it much, particularly if it becomes common practice for people to carry around pure methanol and dilute it as need be (which seems likely, given that this makes things much more compact, and water is available everywhere). Airlines might demand that passengers only carry dilute methanol, but this will be hard to enforce.

Of course, if it is possible to design a fuel cell that can run a laptop for 15 hours or more, then refueling isn't going to be an issue. Passengers simply need to be instructed that refueling on the plane is not permitted, and that they are not permitted to carry fuel with them. People who refuel their batteries before the plane takes off are not going to run out of fuel. The other option is to continue with the route that many airlines have been taking, which is simply to provide electrical outlets in airline seat armrests. In that case, this new technology will be tremendously useful in many situations, but largely irrelevant on aircraft.