The first “Fuel Cell” powered manned plane ever flew recently, Boeing anounced on 3rd of April. The airframe was a Diamond Dimona, modified by Boeing Reserach & Technology Europe (BR&TE). The engine has been replaced by an electical enging coupled to a standard propeller. Electricity was provided by batteries, and a fuel cell.
The fuel cell converts hydrogen into electricity and… water ! No pollution, no green-house effect, at first sight (more on this later…). The major challenge is to build a light and efficient enough fuel cell, and to handle hydrogen. I don’t know yet under which form hydrogen was stocked on board, but it’t either the liquid and thus very cold form, or as a gaz, which tend to be unstable and explosive. Certification challenges in sight !
I’m not an expert in environmental questions, but as far as I know, the fuel cell is not so good from this standpoint. Fuel cell produces power and water from hydrogen and oxygen. True. The problem lies in the production of hydrogen. Extracting it requires a large quantity of energy, and does release some CO2 (once again, I’ve no expertise in this domain, so correct me if I’m wrong).
On the plus side, the environment in which hydrogen is produced can be very controlled. Planes will always fly in the sky, and on-board filter or exhaust gas recuperation is simply not possible. Having non-polluting motors in our atmosphere is a plus, and the effort is worth the result.
Links:
Wikipedia on fuel cell (have a look at the “hydrogen economy” paragraph)
This post is the sixth in a series about how modern planes are designed and operated with maximal care to the enviroment. The first one was about Jet-A1 engines, and the second about composite materials and Computer Aided Design. The thrid was about electrically powered planes, and the fourth about green approach routes design. The fifth post was about alternative fuel.
{ 2 comments… read them below or add one }
Releasing water vapor in the atmosphere is very bad for the global warming!
Water vapor is one of the major gases involved in global warming.
The only clean solution is: saving energy! Less useless transporation, especially.
Pat, water vapor can have some effects, but what about all the other by-products of combustion engines ? Sulphus, NOx, … Once again, I’m not an expert, but I think these are no good at high altitude.