Photovoltaics are an ideal additional generation system for ships, as they have no moving parts, so require little maintenance, with only the replacement of the inverters every >10 years.
The device that directly transforms light into electrical energy is known as a photovoltaic (PV) cell. PV cells can be made of many different technologies including crystalline silicon (c-Si) or various thin film technologies such as Copper Indium Gallium Diselinide (CIGS), amorphous silicon (a-Si), dye sensitised solar cells (dye-cells) or organic photovoltaics (OPV).
A solar cell on its own is unable to survive exposure to the elements for long periods of time. For example, c-Si cells are thin and brittle and will break with any reasonable wind or rain exposure. In order to protect the cells and to connect them in such a way as to provide the desired current and voltage characteristics PV cells are laminated into a PV module. For marine applications, photovoltaic modules are tested to IEC 61701 standard “Salt Mist Corrosion Testing of Photovoltaic (PV) Modules”.
There are many examples of photovoltaic powered ships including the highly successful PlanetSolar which completed its first circumnavigation of globe powered purely by photovoltaics in 4 May 2012. Although some cargo ships use limited amounts of photovoltaics, in reality there is room for a system in the range of 300 to 400 kW capacity on many cargo ships (and another 300 kW if the sides of the ship are utilised).