Boeing announced that it is developing a light aircraft powered by fuel cells and electric motors, which may make it potentially the greenest plane in the air. It would emit no carbon dioxide or other pollutants, and would leave only a slight trail of water. Although it would operate almost completely silently, its most pressing current design obstacle is that it would fly at only 70mph.
The decision to develop the plane comes amid growing concern over high carbon dioxide emissions from the commercial airline industry. Boeing is working with Intelligent Energy, a British fuel cell designer, and hopes that the two-seater aircraft will make its maiden flight in the next year. Boeing claimed that it is designing a demonstration plane in order to determine if the plan is feasible, noting that, although the technology is in its infancy, it has great potential.
The plane is modeled on the Diamond Dimona, an Austrian plane selected for its light weight. Boeing engineers have removed its fuel tank and replaced it with a bottle of compressed hydrogen that will be fed into a fuel cell. From that point, the hydrogen will be chemically combined with oxygen from the air in order to generate power. This will then be fed to an electric motor to turn the propeller. The system is mechanically simple and straightforward. Fuel cells have no moving parts and run silently. Nonetheless, they do tend to be bulky and expensive, hence the reason why their use has never become widespread.
Dr Jon Moore, Director of Communications at Intelligent Energy, stated that technological advances were now making such devices far lighter and cheaper, but aviation remained the biggest challenge. "The secret lies in making a fuel cell powerful enough to get an aircraft off the ground and to keep it climbing," he said. "That takes a huge amount of energy and it is a big obstacle." Boeing thinks that it has overcome this by backing up the fuel cell with batteries that provide extra power for take-off and then recharge while the aircraft is cruising. The Boeing project will be the first manned fuel cell-powered aircraft. Last year AeroVironment, a California-based firm, flew an unmanned surveillance plane, the Global Observer, which was powered by a fuel cell.
Even if Boeing succeeds with its aircraft it will take many years to scale it up for commercial use. Another big problem is finding a supply of "green" hydrogen. Most commercially produced hydrogen is synthesised in refineries from fossil fuels such as natural gas. Critics call this "black hydrogen" because carbon dioxide is generated as a by-product, cancelling out many of the potential benefits.
