Fuel Cell

Fuel cells are just too pricey and complicated to be really practical. I have talked to many companies and to their engineers. Most are still "thinking about" the consumer market. Until the price of the metal hydride storage comes down, fuel cells will be out of most peoples budget, though I'm on their list to be called when they are ready to Beta a system.

Offered by Steve.

Fueling the 21st century

Fuel cells are an efficient and low-polluting way to generate power. The Australian Technology Park in Sydney is about to install Australia's first commercial fuel cell. Bolted under the cargo bay of each NASA space shuttle is a piece of equipment about a metre long. It is shaped like a narrow box and weighs a little over 100 kilograms. This small device is one of the most important items on board the shuttle. If it fails, NASA will call off an entire mission, bringing the crew back to Earth. The function of this device - small enough to fit on your desktop - is power generation. Known as a fuel cell, it efficiently produces enough electricity to run all the equipment on the spacecraft, including the crucial life support systems.

What is a fuel cell?

Fuel cells, like batteries, transform chemical energy into electricity. However, unlike batteries, fuel cells don't store electrical energy. Instead, they convert energy from chemical reactions directly into electrical energy. William Grove produced the first fuel cell over 150 years ago. He based his experiment on the fact that sending an electric current through water splits the water into its component parts of hydrogen and oxygen. So, Grove tried reversing the reaction - combining hydrogen and oxygen to produce electricity and water. This is the basis of a simple fuel cell.

Beyond Batteries

Fuel cells sound like a science-fiction fantasy: an efficient, nonpolluting power source that produces no noise and has no moving parts. But such cells not only exist, they have been providing electricity on spacecraft since the 1960s. In more down-to-earth applications, they could be used as electricity-generating plants or as a power source for nearly exhaust-free automobiles. The main sticking point is the high cost of manufacturing the devices, which has largely limited them to a handful of exotic applications. Now falling prices and new technologies suggest that the fuel cell's day may finally have arrived.

In fuel cells, as in batteries, silent reactions produce an electric current. Unlike batteries, however, fuel cells are almost endlessly rechargeable. The cells run on hydrogen, which reacts with oxygen from the air in such a way that a voltage is generated between two electrodes; the reactions occur in a chemical mediator known as an electrolyte. (Some designs consume hydrogen directly; others start with natural gas that is converted to hydrogen before entering the cell.) Compared with conventional fossil-fuel power sources, fuel cells are exceptionally clean and efficient. Practically their only waste product is water; natural gas-fueled cells do produce some carbon dioxide as well, though less than would be created if the fuel were burned.