Tuesday, July 1, 2008

Solar Sail that use photovoltaic panels

Another futuristic design of passenger ferry is the one shown in the picture below. Solar sailor combines solar and wind energy to power the boat.
There are a number of design constraints which naval architects usually face when designing sail boat. Wind blowing on horizontal direction usually forces a ship or a boat to an inclined position, thus creating frequent rolling to the vehicles. In addition, if solar panels are to be installed the amount of energy will not be fully enough to drive electric motors that propel the boat. On the other hand, if sails are to be installed, it will not fully efective in propelling the boat all the time because wind blows are unpredictable. There are times when there is no wind blowing or if there is one, its direction might be from the front.
So, naval architects will have to compromise all these constraints in order to reach an optimum design which effectively rely on renewable energy. To minimize water resistance and maintain boat stability, catamaran (twin hulls) or trimaran (three hulls) is applied. Boat material will have to be as light as possible so that the boat will not need a lot of energy to  move.

Improvements in photovoltaic technology have brought many design possibilities come to reality. For instance, thin film photovoltaic cells or commercially called flexible photovoltaic panels in the near future will be taken into consideration when naval architects need to design sails for their boat. Besides having lighter weight, its flexibility can enable it to be integrated into the sail. But flexible photovoltaic panels have to be backed up by strong sail material which can endure stresses and strains caused by wind blows.
The application of solar sail will become the primary choice in the future. So, a green boat will be driven by electric motors whose electricity is supplied by a sail which also propels the boat.
Another problem that we must consider is about toxic substances contained in batteries that store the electrical energy. Batteries must be sealed properly to prevent them from any leakages that can pollute sea water.
When all these design constraints have been solved or compromised, passengers can enjoy their trip free of noise, vibrations, and most importantly toxic fumes.
The above boat is presented in a web page on the following link: It says that the boat will carry passengers to Alcatraz, a famous island prison located in the middle of San Francisco bay.
Conventional Sail Boat
Even though conventional sail boat has long been replaced by cargo, passenger ships and airplanes in transporting people and goods, they are still popular among hobbyists and tourists. One important example is Phinisi schooner from Indonesia. This type of sail boat has got 2 masts where the sails are installed. In the part, the boats are used to transport people and goods between small and big islands in Indonesia. Today more Phinisi schooners are being developed to cater the increasing demand for liveaboard vessels that transport visitors to various destinations in this country such as Raja Ampat, Cendrawasih bay, and Wakatobi. The sails and the masts are not used during the whole operation of the vessel. These liveaboard vessels have been installed with marine diesel engines to enable them to travel faster at sea. 

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