PHOTOVOLTAIC APPLICA-TIONS

Jiyeon HYUN

What is photovoltaic ?

• 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.

Advantages

• the highest power density among re-newable energies

• It can be used for long time. (40years)

• Reduce pollution

Disadvantages

• Wide places is needed.

• Initial cost is high

Principal

• N type of silicon / P type of silicon - silicon has for valence electrons, all of which are normally part of bonds in a silicon crystal. - an atom such as phosphorus, having five valence electrons. (n type) - An impurity atom with three valence electrons (such as boron) would sit in the position of the original silicon atom (p type)

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• Light incident on the cell cre-ates electron-hole pairs, which are separated by the potential barrier,

creating a voltage that drives a current through an external cir-cuit.

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PV system types

• GRID-TIE (BATTERY FREE)

• GRID-TIE WITH BATTERY BACKUP

• STAND-ALONE

• PV DIRECT

GRID-TIE (BATTERY FREE)

This system does not provide backup power during a power outage (even if the sun is shining) but for sites with reliable grid power, this is usually the logical system choice.

GRID-TIE WITH BATTERY BACKUP

It can also push excess electricity produced to the electric utility grid but has the added feature of batteries in order to power some selected backup loads when the grid is down.

STAND-ALONE

The Off-Grid or Stand-Alone PV System incorpo-rates large amounts of battery storage to provide power for a certain number of days (and nights) in a row when sun is not available.

PV DIRECT

PV Direct systems are usually very simple sys-tems where the photovoltaic panel is con-nected directly to a motor or pump which matches the voltage and amperage output of the panel.

conference• http://en.wikipedia.org/wiki/Phot

ovoltaics• http://www.nrel.gov/docs/legosti/

old/1448.pdf• http://blog.naver.com/kunastory?

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• http://www.aladdinsolar.com/pvsystems.html

Thank you