Photovoltaic

The term photovoltaics derives from the Greek word phos meaning light and the word volt, unit for electrical voltage.


Photovoltaics is a science, which examines light-electricity conversion, respectively, photon energy-electric current conversion. Solar photovoltaics is growing rapidly, albeit from a small base, to a total global capacity of 40,000 MW at the end of 2010. More than 100 countries use solar PV. Installations may be ground-mounted (and sometimes integrated with farming and grazing) or built into the roof or walls of a building (building-integrated photovoltaics).


Solar cells

Photovoltaics are best known as a method for generating electric power by using solar cells to convert energy from the sun into a flow of electrons. The photovoltaic effect refers to photons of light exciting electrons into a higher state of energy, allowing them to act as charge carriers for an electric current.
Solar cells produce direct current electricity from sun light, which can be used to power equipment or to recharge a battery. The first practical application of photovoltaics was to power orbiting satellites and other spacecraft, but today the majority of photovoltaic modules are used for grid connected power generation. In this case an inverter is required to convert the DC to AC.



Photovoltaic modules

This is an assembled set of interconnected solar cells. The photovoltaic modules are commonly known as solar panel is used as a component in large photovoltaic system to generate electrify.
Today, the overwhelming majority of PV modules (more than 95%) are crystalline silicon, made from the second most abundant element on earth.
All modules are rated by manufacturers in terms of their peak power (Wp) under standard test conditions: ie. 1000W/m² of sunlight (‘peak sun’); 25 ºC; and air mass of 1.5.
Modules
that are currently on the market with efficiency between 4%-19%, this means that the maximum power that can be obtained at 1m ² 190Wp.

Module can be classified into three type of crystal:
  • Monocrystalline and polycrystalline (14%-19%)
  • Thin-film (5%-13%)
  • amorphous (3%-6%)


Why put solar power?

  1. Free electricity fron the Sun. The Sun is inexhaustible energy source.
  2. Harmless to the environment.

  3. Photovoltaic modules have a very long life.

  4. Very easy to install and maintain.

  5. Becoming energy independent.

  6. State subsidies.

  7. An additional source of income.