Photovoltaic Systems

Prepared By:VISHAL G. BARAVALIYA

Guided By:Prof. J. I. Patel

What is PV System?

Photovoltaic (PV) system is an electrical system consisting of array of one or more PV modules, conductors, electrical components, and one or more loads which Convert solar radiation into electricity.

PV systems use wafers, typically made of crystalline silicon.

Other component are Inverter, charge controller, batteries etc.

Basic Diagram of PV-System

load

energysource

power conditioning

energyconversion

InverterPV Array

powerdistribution

LoadCenter

Batteryenergy

storage

electricutility

The total components and subsystems that, in combination, convert solar energy into electrical energy suitable for connection to a utilization load.

The heart of a photovoltaic system is a solid-state device called a solar cell.

Material used in PV-cell

Crystalline Materials Single-crystal silicon Polycrystalline silicon Gallium Arsenide (GaAs)

Thin Film Materials Amorphous Silicon (a-Si) Cadmium Telluride (CdTe) Copper Indium Diselenide (CuInSe2, or CIS)

How Does It Work?

PV cells are made of dissimilar materials

(n and p type silicon) which are in

contact and form a barrier at the

junction.

When sunlight hits the cell, it creates a

electron and a hole pair at the junction.

Connecting both sides to an external

circuit the current will flow.

Ph

oto

volta

ic

Th

eory

p-Silicon

n-Silicon

+ + + + + + + + + + + + + + + + + +

- - - - - - - - - -

One silicon solar cell produces very low output so

to increase power output many cells connected

together which is called module. Module is the basic building block of systems which can

connect modules together which is called an array

to get any power configuration Cells.

Connect Cells To Make Modules

Types of PV Systems Stand-alone system it is independent of all sources &

used in remote applications. Grid connected system it is connected with grid and store its

surplus power into grid by concept of net metering.

Hybrid system it receives a portion of its power from

more than one sources like wind generator or any fuel fired generator

10

Here is a stand-alone PV system in Oix, La Garrotxa in rural Spain. This system consists of a 900-watt PV array with inverter and batteries. More than 60 rural homes in this mountainous area have been electrified with PV.

This picture include PV-wind-diesel hybrid system in Mexico that provides village-wide power for 43 homes, three schools, two stores, a church and an auditorium.

Application of PV Systems

Advantages

ReliableNo FuelsLow

MaintenanceLong-term

SavingsNo PollutionNo Noise

• Solar electric generation is economically superior where grid connection or fuel transport is difficult, costly or impossible.

• When grid-connected, solar electric generation replaces some or all of the highest-cost electricity used during times of peak demand (in most climatic regions). This can reduce grid loading, and can eliminate the need for local battery power to provide for use in times of darkness.

• Once the initial capital cost of building a solar power plant has been spent, operating costs are extremely low compared to existing power technologies.

Disadvantages

High Initial Cost Specialized Maintenance

Batteries &Power Conditioning Equipment

Large Space Solar electricity is not available at night and

is less available in cloudy weather conditions from conventional silicon based technologies.

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