The Danish consulting engineering company, Haldor Topsøe, has developed fuel cells, which as the first in the world drive a vessel forward in open sea.

The vessel Undine has got installed 24 fuel cells from Haldor Topsøe.
-We are very pleased that the fuel cells are now part of the vessel’s power supply. Fuel Cells are a central technology on the way to more sustainable shipping, says Benedict Richter, business development manager at Haldor Topsøe.
The fuel cell unit produces power to the vessel with very low emissions. The fuel cells are driven by methanol, and CO2 and water are the only by-products.

Source: epn.dk