HANDS ON GUIDE

9 - Laptops powered by fuel cells

No need to recharge every day

WHAT IS IT?

Memory capacities are constantly growing; CPUs get faster; hard drives get bigger. The technology behind the batteries in our laptops hasn't changed much since the 1980s however. Until laptops and mobile devices can function away from a power source for extended periods, computing will always remain bound to the desktop. Scientists and hardware manufacturers would love to replace the aging and inefficient Lithium Ion technology with something that lasts longer and is less explosive. An ideal candidate is fuel cells. At IDF in 2006, a company called UltraCell demonstrated a laptop running for two days with a fuel cell.

HOW DOES IT WORK?

A fuel cell uses a reaction between a chemical and oxygen to pass electrons into a circuit, thereby powering it. Different substances can be used as the reactant, such as hydrogen or alcohol. This is consumed as the device continues to draw power, so any commercial fuel cell would need to be topped up with reactant. For cars, this would be no different to filling the engine at a petrol station, and for laptops it would mean replacing a cartridge in the battery. Fuel cells are usually designed to produce harmless waste substances such as water or gas. These are less harmful than the cocktail of planet-warming gases given off by car engines, but need to be taken care of, especially since water doesn’t mix with laptops that well.

WHAT COULD GET IN THE WAY?

Fuel cells have been described as a holy grail of energy storage, as hydrogen based cells could replace the petrol engines in our cars and methanol based cells replacing the batteries in our laptops. Some had even suggested that by 2008, the world would have shifted to a hydrogen economy, replaced petrol pumps with hydrogen stations and all our laptops would be powered by fuel cells.

It hasn’t happened though. Fuel cells are still prohibitively expensive. The cost of developing them is dropping, but not yet to the point where they can be included in an Asus EeePC without turning a low cost laptop into a project with the budget of a NASA mission. Lithium Ion batteries may be inefficient, but they’re affordable.

An even bigger problem is reliability. With extremely flammable substances in use, there is a risk the reactant may become unstable and explode. Many of the reactions in a fuel cell give off a lot of heat, which isn’t good if there’s a small tank of explosive reactant nearby. There are ways to avoid this, but they add to the cost of an already expensive technology.

ETA

Five to ten years

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