Uninterruptible Power Supply | UPS
Fermi Dirac Distribution Function
Fault of Electric Cable
Energy Bands in Crystals
Gallium Arsenide Semiconductor
Atomic Energy Levels
Solar Energy Solar Electricity
Solar Energy System | History of Solar Energy
Types of Solar Power Station
Components of a Solar Electric Generating System
What is photovoltaic effect?
Staebler Wronski Effect
Working Principle of Photovoltaic Cell or Solar Cell
Characteristics of a Solar Cell and Parameters of a Solar Cell
Solar Cell Manufacturing Technology
What is a Solar PV Module?
What is Standalone Solar Electric System?
Steam Boiler | Working principle and Types of Boiler
Methods of Firing Steam Boiler
Fire Tube Boiler | Operation and Types of Fire Tube Boiler
Water Tube Boiler | Operation and Types of Water Tube Boiler
Steam Boiler Furnace Grate Firebox Combustion Chamber of Furnace
Feed Water and Steam Circuit of Boiler
Boiler Feed Water Treatment Demineralization Reverse Osmosis Plant Deaerator
Coal Combustion Theory
Fluidized Bed Combustion | Types and Advantages of Fluidized Bed Combustion
Steam Condenser of Turbine
Jet Condenser | Low Level High Level Ejector Jet Condenser
Surface Steam Condenser
Economics of Power Generation
Cooling Tower Useful Terms and Cooling Tower Performance
Cooling Tower Material and Main Components
Power Plant Fire Protection System
Hydrant System for Power Plant Fire Protection
Medium Velocity Water Spray or MVWS System for Fire Protection
Foam Fire Protection System
Fire Detection and Alarm System
Gas Extinguishing System
Electric Power Generation
Power Plants and Types of Power Plant
Thermal Power Generation Plant or Thermal Power Station
Hydro Power Plant | Construction Working and History of Hydro power plant
Nuclear Power Station or Nuclear Power Plant
Diesel Power Station
Why Supply Frequency is 50 Hz or 60 Hz?
Economiser in Thermal Power Plant | Economiser
MHD Generation or Magneto Hydro Dynamic Power Generation
Cogeneration | Combined Heat and Power
Thermoelectric Power Generators or Seebeck Power Generation
Cost of Electrical Energy
Gas Turbine Power Plant
Steam Dryness Fraction
Superheated Steam and Steam Phase Diagram
Vapour Properties Mollier Chart Heat Capacities
What is Steam Flashing?
How to Calculate Steam Consumption During Plant Start Up
Effective Steam Distribution System
What is Water Hammer?
Engineering Thermodynamics Part 1
Science of Engineering Thermodynamics Part 2
Basic Law of Conservation and First Law of Thermodynamics
Carnot Cycle and Reversed Carnot Cycle
Enthalpy Entropy and Second Law of Thermodynamics
Rankine Cycle and Regenerative Feed Heating
Rankine Cycle for Closed Feed Water Heaters and Rankine Cycle Cogeneration
Ideal Verses Actual Rankine Cycle
Rankine Cycle Efficiency Improvement Techniques
Basic Wind Energy
Wind Turbine | Working Types and History of Wind Turbine
Theory of Wind Turbine
Solar Cell Manufacturing Technology
This ensures the availability of cheaper solar cells. Two most common techniques of producing silicon wafers are the chzrolaski (CZ) and floating zone (FZ) techniques.Let us discuss some common techniques of solar or photovoltaic cells.
Thin Film Solar CellThis is the cheapest technology available for solar cell. Most commonly used thin-film solar cell is Amorphous solar cell. Here, a very thin film of amorphous silicon of few microns thick is used as active layer of the cell. Reliability and lifespan of these cells are quite poor. The main advantage of this technology is that it can be manufactured in different shaped hence can be mounted in any form of surface. Amorphous silicon is basically a silicon substance but in non crystalline form. It is specially made by deposition of silicon based gases on subtract. The chemical bonding between atoms in amorphous silicon is quite similar to that of crystalline silicon but only difference is that the material has no regular lattice structure. In amorphous silicon a significant number of silicon atoms create covalent bonds with three neighbour silicon atoms and rest one valence electron of these silicon atoms creates bond with hydrogen atom. While a mixture of silicon containing hydrogen gas (SiH4) and raw hydrogen gas pass through between two electrodes in a vacuum chamber and an RF voltage is applied between these electrodes, hydrogenised silicon will be deposited on a warm subtract attached to the electrodes. In this way very thin film of hydrogenised silicon can be created. The thickness of the film may be less than 1 micron.
The main advantage of amorphous silicon is that, it is quite cheaper than crystalline silicon. For a given thickness, the light absorption capacity of amorphous silicon is about 2.5 times more than that of crystalline silicon. As the quantity of required silicon for producing micro thin film, is quite low compared to crystalline silicon, the cost as well as the weight of amorphous silicon solar cell or a-Si:H solar cell is much low. Amorphous silicon is flexible in nature hence can be easily deposited on flexible and roll way type subtracts. In addition to Amorphous solar cells there are also Cadmium Telluride (CdTe) and Copper-Indium-Gallium-Selenide (CIGS) thin film solar cells available in the market. The materials used for making the active layer of amorphous cells is amorphous silicon, Cadmium and Tellurium are used for Cadmium Telluride (CdTe) solar cells and Copper, Indium, Gallium, Selenium are used for Copper-Indium-Gallium-Selenide solar cells. The efficiency of amorphous cell is about 6 to 8 % and this low efficiency of amorphous cells is some extend improved in Cadmium Telluride (CdTe) and Copper-Indium-Gallium-Selenide (CIGS) thin film solar cells. The efficiency of Cadmium Telluride (CdTe) and Copper-Indium-Gallium-Selenide (CIGS) thin film solar cells is about 8 to 11 %. Open circuit voltage of amorphous cells is 0.7 to 1.1.volt and same for the Cadmium Telluride (CdTe) and Copper-Indium-Gallium-Selenide (CIGS) thin film solar cells are 0.8 to 1 volt and 0.5 to 0.7 volts respectively.
Crystalline Silicon Solar CellCrystalline Silicon Solar Cell has most advantageous against other available technologies of solar cell manufacturing. But these cells require purified silicon as row material which is quite expensive. Here naturally available silicon quartzes are melted, purified and then crystallized in ingots. Then these ingots then further cut into smaller sized ingots and then these ingots are sliced into number of thin silicon wafers. These wafers were generally made 0.3 mm thick in early days but now technology has developed to make them about 0.15 mm thick. This thickness of the silicon crystal wafer is important in the view of cost optimization of the cell. Then these wafers are chemically treated for doping with impurities to create p-n junction across them.
Then negative and positive metallic contacts are fabricated on top and bottom the cells by screen printing techniques. The cells typically produce 0.5 to 0.6 volts across them at standard working conditions hence numbers of such cells are wired in series to produce standard 6 or 12 volts. Numbers of such series combinations are then arrayed in parallel on a glass substrate or some kind of insulated reinforced base substrate to increase the power capacity of the module. Then the module is covered with none conducting transparent encapsulating resin and then a protective transparent film. The whole module is then framed with aluminium channel to provide ultimate reinforcement to it. The required power output is achieved by interconnecting suitable number of such modules in an array.