Tuesday, 19 August 2014

PhotoVoltaic Technology

                             How does PV cell works?

  • PV effect which is directly convert light(photons) energy into electric energy(DC voltage) by using semiconductor materials.
  • PV cell is also known as solar cell.A solar cell consist of P type( silicon-boron) layer and N type(silicon-phosporous) layer.
  • When sunlight(photons) strikes solar cell ,it breaks PN junction and generates DC voltage.  

Applicable semiconductor materials:

          •   Silicon(Si)
          •   Gallium Arsenide(GaAs)
          •   Cadmium Telluride(CdTe)
          •   Copper Indium Diselenide(CIS) 
          •   Hydrogenated Amorphous Silicon 

Types of Solar cells:


Crystalline silicon:
  •  The majority of PV cells produced by using Crystalline silicon as it is a light absorbing semiconductor.11% to 16% efficiency.
           Mono crystalline-it is made from single crystal of pure silicon.it can be easily recognize by uniform looking and cell corner is missing.it is superior than poly crystalline due to high efficiency(perform 10% more than poly crystalline.mono crystalline efficient per area.it is potential upto 50 years longevity.
           Poly crystalline-it is made from multi crystalline silicon.these are inconsistencies in color and sort of granite.cells are in square.Less efficiency compare to mono type and requires more area to get same power of mono crystalline.only go up to 25 years.

Thin-Film:Thin film solar technology is thinner and flexible.Thin film solar panels only reach 6% to 11% efficiency and expensive so less peoples only used.
Technology Maximum Demonstrated Efficiency for small cells* Advantages Disadvantages
a-Si 12.2% Mature manufacturing technology Low efficiency
High equipment costs
CdTe 16.5% Low-cost manufacturing Medium efficiency
Rigid glass substrate
CIGS 19.9% High efficiency
Glass or flexible substrates
Film uniformity challenge on large substrates
Costly traditional processes
 

                     

            


                              

 

Monday, 18 August 2014

why we go for solar energy

WHY WE GO FOR SOLAR ENERGY?


Electrical energy is in huge demand especially in TAMIL NADU. Energy demand is going to be increasing in the coming year also. Hydraulic energy, thermal energy, atomic energy, wind energy and solar energy are the few resources available. Solar energy and wind energy are renewable energy. 

GREEN SOLAR ENERGY

   

  •    Hydraulic energy is very economical because one stage of system (rotating the   turbine) is free of cost. But this system is seasonable and the potential is limited.

  •    Thermal energy (coal based, petroleum based) is costlier and polluting the environment (emission of CO2).

  •   Atomic energy is very costly investment and hazardous.

  •   A renewable energy is wind and solar are better alternative than the conventional  energy source.

  •   Wind energy is renewable, but seasonal and unpredictable-not reliable.

  •   Solar energy is predictable and reliable and renewable. The only restriction is it is available only 50%of the day (day time only).

ADVANTAGES:

  
  •     You don't pay for sunlight.solar power provides energy independence.
  •     Good for environment,it helps to slow/stop global warming(no green house gases).
  •      Easy installation.
  •      There is no moving parts so maintenance is easy.
  •      It can be easily deployed for both home and business users.