Photovoltaics in Indonesia

The biggest electric generation from solar cell (photovoltaic) in Indonesia has built in Bunaken Manado.

It gets special attention electricity state (PLN) director Dahlan Iskan cause by he wants to know and understand what is going to be a trouble for operate and maintenance (other renewable power from wind in Nusa Penida Bali can not be operated maximum due to the wind is fluctuating and very difficult for maintenance).

Photovoltaic electric generation in Bunaken has capacity 400kWP (kilowatt peak) and can supply two counties. At the same time, photovoltaic energy also built at Wakatobi island around Celebes and Raja Ampat Papua. Next plan, photovoltaic energy will be support to city lighting and big store electricity.

For this opportunity of Dahlan’s visit also try to clean up the cell as a picture above.


Photovaltaic conversion is the direct conversion of sunlight into electricity with no intervening heat engine. They can be constructed as standalone systems to give outputs from micro-watt to megawatt.

That is why they have been used as the power sources for calculators, watches, water pumps,remote building, communication, satellites and space vehicles and even megawatt scale power plants.

Photovoltaic cell have been made with silicone (Si), gallium arsenide (GaAs), copper indium diselenide (CIS), cadmium telluride (CdTe) and e few other material. The common denominator of PV cells is that a P-N junction. Understanding P-N junction is thus at the heart of understanding how a PV cell convert sunlight into electric.

P-N Junction Theory.
N-layer has an abundance a free electrons and P-layer has an abundance of free holes. Each free electron on N side comes a neutral electron donor impurity atom such as arsenic (As) whereas each free hole on the P-side of the junction comes from a neutral hole donor (acceptor) impurity atom such as boron (B).

Hole Theory

When negative charge electron leaves the As atom, the As atom becomes a positively charge as ion. Similarly when positively charge hole leaves the B atom, the B atom becomes negatively charge B ion.

Thus as electron diffuse to the P-side of the junction, they leave behind positively charge electron donor ion that are covalently bound to the Si lattice.





A holes diffuse to the N-side of the junction, they leave behind negatively charge hole-donor ions that are covalently bound to the Si lattice on the P-side of the junction.

The diffusion of charge carrier a cross the junction thus created an electric field across the junction.





The Illuminated P-N Junction.


The energy of a photon is given by Equation :

E = hc / λ

where λ is the wavelength of the photon in mm,
h is Planck’s constant (6.625 x 10^-34 J.s),
and c is the speed of light (3 x 10^8 m/s).

If 1 J = 6.24 x 10^18 (eV)
The energy of a photon in electron-volts (eV) becomes 1.24 x 10^-6 (eV).





If a photon has an energy that equals or exceeds the semiconductor bandgap energy of the p-n junction material, then it is capable of creating an electron-hole pair (EHP).

For Si, the bandgap is 1.1 eV, so if photon wavelength is less than 1.13 μm, which is in the near infrared region, then the photon will have sufficient energy to generate an EHP.

Photon Energy Animation


Please click http://scient-tech.blogspot.com/2011/08/solar-power.html for see animated illustration for solar cell.