subject: Solar Power [print this page] The sun is our primary source of energyThe sun is our primary source of energy. An arrangement of photovoltaic cells is called a solar panel; solar power is harnessing renewable energy from the sun that is totally pollution free.
This power can be used for commercial and residential applications. One installation of large photovoltaic system contains several solar panels known as photovoltaic array. Most of the modules use wafer-based i.e. crystalline silicon cells or sometimes thin-film cells are also used.
Electrical connections are made between cells in a series to get a desired voltage output. If the cells get heated then the operating efficiency is reduced so good ventilation is provided to the module to minimize heating of the cells.
There are two concepts of design: In one module sunlight falls on an array of lenses or mirrors that concentrates the light which is then directed onto an array of solar cells. This is a cost-competitive way of using the cells.
The second design is based on the concept of splitting the light into its different wave length ranges and then the beams are directed to different cells that are tuned to the proper wavelength ranges. The efficiency of this model is raised by 50% and infrared photovoltaic cells can produce power at night.
The different modules of photovoltaic cells are
Crystalline silicon modules
The most commonly produced photovoltaic cells are from silicon. Silicon is commonly used as a semi-conductor. In the construction of a solar panel the key component is polycrystalline silicon. The modules can be mono-crystalline or multi-crystalline. Mono-crystalline silicon is superior and much more priced and efficient than multi-crystalline silicon.
Thin film modules
These are advanced modules and known as third generation solar cells. This is made by depositing photovoltaic material on a substrate in one or more than one thin layers. The thickness of the film varies from a few nano meters to tens of micro meters. The efficiency of these modules is high and conversion is at low cost.
These can be of two types: Rigid Thin Film module: In this the module and the cell are manufactured in the same production line. A glass substrate is used to create a cell and in situ electrical connections are made. Lamination of the substrate is done, usually to another glass sheet.
Flexible Thin Film module: In this module the deposition of photoactive layer is done on a flexible substrate. The cells in the module are assembled by laminating them to a fluoropolymer which is colorless and transparent.
Solar power is a renewable source of energy that does not cause pollution. It is expensive but newer technologies are at work trying to make it cost effective. We are living in that era where it becomes imperative that we start using alternative sources of energy that are environment friendly.
