Environmental Engineering Reference
In-Depth Information
Another interesting concept is based on modern power kites (Figure 14.13). A start-
ing and landing system automatically lowers and raises the power kite and the
cabling rope. The kite fl ies at a height between 100 and 300 m. The wind conditions
at this height are higher and more constant than on the deck of a conventional sailing
ship. The cabling rope, which is made of modern synthetic material, is attached to
the forepart of the ship and transfers the driving force there to the ship. The steering
of the kite is completely automated. Through a shortening or lengthening of the
steering lines, a power kite can be controlled like a paraglider and orientated with
optimal precision depending on wind direction, wind intensity and a ship's course.
With a sail surface of up to 5000 square metres, the power output should reach up
to 5000 kilowatts or 6800 HP. On a yearly average a power kite should be able to
reduce fuel requirements, and consequently carbon dioxide emissions, by 10 to 35%.
Under optimal conditions savings of up to 50% are sometimes possible.
Modern wind drives can therefore make a considerable contribution towards reduc-
ing carbon dioxide emissions. Emissions in shipping can even be eliminated com-
pletely if biofuel or renewably produced hydrogen is used to cover the rest of the
fuel requirements of conventional ship drives.
Figure 14.13
Modern automatically controlled power kites can reduce the fuel requirements of
conventional shipping by up to 50% and, when combined with biofuels, even make it carbon-free.
Photos © SkySails, www.skysails.de.
14.4.2 Solar Ferry on Lake Constance
Solar boats offer climate-compatible travel on water even if there is no wind, espe-
cially for short distances. The Helio solar ferry on Lake Constance has been connect-
ing the German town of Gaienhofen to Steckborn in Switzerland since May 2000
(Figure 14.14). The 20 m ship can carry 50 people, and electric engines with an output
of 8 kilowatts each provide for a maximum speed of 12 km/h. The batteries of the
boat ensure a range of 60 to 100 km of travelling distance. The roof of the boat consists
