Future Transportation Systems - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 285

Fig. 17.16 Solar and wind
energy supply for a ship
automatically adjustable sail
controlled by micro computer
solar cells
to successfully navigate around the world using photovoltaic cells [ 60 ]. The ship is
23 m (75.4 ft) long, 6.1 m (20 ft) high, and reaches a weight of 85 t (187 225 lbs).
It is built from CFC and other light weight plastics, and can run with battery power
for 66 h, and costs about €1.0 million, i.e., US $1.43 million.
Large vessels such as bulk carriers are also experimenting with photovoltaic
cell technology. By means of some examples, the solar panels are installed on the
deck of a bulk carrier; see Fig. 17.16 .
Initial tests show that solar cells generate 1.4% more energy at sea than on land
because of higher radiation intensity. However, photovoltaic solar power provides
approximately 1-3% of the on-board electricity of large tankers, when all the free
places are covered by solar panels. From experience, current panels survive severe
conditions in heavy storms with constant rain, lightning, and pounding from waves
up to 4 m (13.1 ft) high.
The far future aim is to use solar and wind power to reduce fuel consumption
and CO 2 emissions by up to 50%. The newest photovoltaic cells have efficiency of
more than 17.5%, but their durability and costs for the marine technique must be
still improved. The same requirements are valid for other alternative energy
sources. Despite all improvements, the current level of alternative technology can
only save a small part of the energy that a ship needs [ 61 ].
17.3.2.4 Hydrogen Fuel Cells in Ships
Fuel cell propulsion has been developed for submarines of first, because they
operate without ambient air for a long time. Fuel cell technology in civil ships
would provide a lot of advantages such as better environmental protection, lower
costs, and higher durability than conventional propulsion systems. Civil ships
usually use small and in the most cases transportable 160 kW (215 HP) hydrogen
fuel cells in 20 ft containers consisted of four separate modules by a performance
of 4 9 40 kW (4 9 54 HP).