FUEL CELL SUB DEBUTS

On Monday, the first fuel cell-powered submarine made its maiden voyage from the German port of Kiel into the Baltic Sea, the Associated Press reports.
According to StrategyPage, the German U-31 sub combines hydrogen and oxygen supplies in nine PEM (polymer electrolyte membrane) fuel cells. Each of these produces up to 50 KW of electricity. Water is the only waste product.
"This type of power plant generates no heat or noise and is probably the most difficult to detect sub in the world," the site says. "The 1500 ton boat... can travel silently underwater for 15-20 days. Currently, only nuclear subs can stay under that long."
Naval historian Norman Friedman isn't impressed, however.
"In (the) sub that the Germans have, the fuel cell is used for loitering for significant periods at very low speed," Friedman told New Technology Week. "It's not used for main power. You still have to use your diesel (engines)... If you have to move several thousand miles, you're going to do it on diesels."
The U-31 also has a diesel engine, though, and travel underwater at speeds up to 36 kilometers per hour on this power. This 212A-class sub holds a crew of 27.