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Eng. Firas Alawneh

PV Systems – Applications and Components

Outline• From Solar Cell to Module to Array

• PV Module Architecture

• PV Module Components

• PV Module Temperature Coefficients

• Hotspot Phenomenon

• Bypass and Blocking Diodes

• Shadowing Effect on PV Modules and Arrays

• PV Module Nameplate

• PV Module Datasheet

• Typical PV Modules Efficiencies

• Types of PV Systems– Standalone “off-grid”

– Grid connected “on-grid”

• PV Mounting Structures

• PV Array Tilt Angle “Inclination” Effect

• PV Array Azimuth “Orientation” Effect 2

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From Solar Cell to Module to Array

PV Module Architecture

4V

12 V Standard

PV Module

(Mainly used for

charging 12 V

battery banks)

IV Curve for a 12 V standard PV module

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PV Module Components

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PV Module Nameplate

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PV Module Datasheet

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Typical PV Modules Efficiencies

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Pmpp (T) = Pmpp (25°C) [ 1 + γPmpp ×(T – 25°C) ]Vmpp (T) = Vmpp (25°C) [ 1 + βVmpp × (T – 25°C) ]Impp (T) = Impp (25°C) [ 1 + αImpp × (T – 25°C) ]Voc (T) = Voc (25°C) [ 1 + βVoc × (T – 25°C) ]Isc (T) = Isc (25°C) [ 1 + αIsc × (T – 25°C) ]

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Excercise

For Sharp PV Module Model No. NU-E245 (J5),

calculate :

1.Voc(+75°C, 1000 W/m2, 1.5 AM)?

2.Voc (-5°C, 1000 W/m2, 1.5 AM)?

3. Isc(+75°C, 1000 W/m2, 1.5 AM)?

4. Isc(-5°C, 1000 W/m2, 1.5 AM)?

5.Pmp (+75°C, 1000 W/m2, 1.5 AM)?

6.Pmp (-5°C, 1000 W/m2, 1.5 AM)?

7.Pmp (+25°C, 500 W/m2, 1.5 AM)?

8.ηmp(+25°C, 1000 W/m2, 1.5 AM)?

9.FF(+25°C, 1000 W/m2, 1.5 AM)?

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The hot spot phenomenon happens when one cell of the panel is shadedwhile the others are illuminated, and when this shaded cell is not able toexhaust its generated power dissipation. The shaded cell behaves as adiode polarized in reverse and generates reverse power PS. The other cellsgenerate a current that flows through the shaded cell and the load RLoad.

Any solar cell has its own critical power dissipation PC that must not beexceeded and depends on its cooling and material structures, its area, itsmaximum operating temperature and ambient temperature. A shaded cellmay be destroyed when its reverse dissipation exceeds PC. This is the hotspot.

The manufacturers usually define a breakdown voltage VC. Its valuedepends on the solar cell technology (poly-silicon or mono-silicon) and themanufacturing process. There is no risk of hot spot while PS < PC.

To eliminate the hot spot phenomenon, a dedicated circuit should bypassthe partially shaded module and eventually it should maintain the operationof the other PV modules creating a path for their current.

Hot spot phenomenon

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Bypass Diodes Inside Junction Box

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The bypass diode principle is to use a diode in reverse paralleling with several solarcells. The bypass diode is blocked when all cells are illuminated, and conductswhen one or several cells are shadowed.

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Building A PV Array (Parallel x Series)

P x S = 2 x 3

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Series and Parallel Connections

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Blocking Diodes

A blocking diode prevents current to flow reversely in PV string (series-connected modules).

A bypass diode prevents hotspot effect in case of shadowing.

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Shadowing Two Series-Connected PV Cells

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Shadowing Two Parallel Strings

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Types of PV Systems

Standalone “off-grid”

Grid-connected “on-grid”

Without storage

With storage

Hybrid Systems directly connected

to the public grid

connected to public grid via house grid

Motors “e.g. pumps”

DC Systems

AC Systems

with wind turbine

with diesel generator

with public grid backup

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Off-grid / Without battery storage / Direct-coupled DC system

PV Array DC Load

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Solar Water Heaters

Off-grid / Without battery storage / Direct-coupled DC system

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Off-grid / Without battery storage / Power-conditioned DC system

PV Array DC Load

DC/DC Power

Conditioning

Unit

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Off-grid / Without battery storage / Power-conditioned DC system

DC Submersible Water Pumping System

PV Array DC/DC Pump Controller DC Submersible Pump

Variable Voltage

(Proportional to Solar Intensity)

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Off-grid / Without battery storage / Power-conditioned AC system

PV Array AC Load

DC/AC Power

Conditioning

Unit

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Off-grid / Without battery storage / Power-conditioned AC system

AC Submersible Water Pumping System

PV Array DC/AC Pump ControllerAC Submersible

Pump

Variable Voltage & Frequency

(Proportional to Solar Intensity)

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Off-grid / With battery storage / DC system

PV Array DC Load

Charge

&

Load

Controller

Battery

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Solar Home Systems & DC Industrial Systems

PV ArrayDC Load

Off-grid / With battery storage / DC system

Battery Bank

Charge & Load Controller

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Off-grid / With battery storage / AC system

PV ArrayCharge

Controller

Battery

DC/AC

Inverter

AC

Load

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Solar Home Systems & AC Industrial Applications

PV Array

AC Load

Off-grid / With battery storage / AC system

Battery Bank

Charge Controller

DC/AC InverterWith fixed voltage & frequency

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Off-grid / With battery storage / Hybrid System

PV ArrayCharge

Controller

Battery

DC/AC

InverterAC

LoadOther

Source

Power

Conditioning

Unit

DC-Coupled

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Hybrid Solar/Wind

PV Array

AC Load

Battery Bank

Charge Controller

Off-grid / With battery storage / Hybrid System

DC/AC Inverter

Wind Turbine

Wind Controller

DC-Coupled

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Off-grid / With battery storage / Hybrid System

PV ArrayPV

Inverter

BatteryDC/AC Inverter

AC

Load

Other

Source

Power

Conditioning

Unit

AC-Coupled

Grid Former

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Inverters

Off-grid / With battery storage / Hybrid System

AC Bus (3-phase)

Hybrid Solar/Wind/Diesel

AC-Coupled

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• The grid is the network of cables by which electricity is

transported from power stations to houses, buildings &

other places.

• A grid connected PV system is linked to this grid or

electrical network. This means that it can deliver the

electricity it produces into the electricity network and

therefore no battery or other storage is needed.

On-grid PV Systems

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On-grid PV Systems

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BLOCK DIAGRAM OF GRID

CONNECTED PV SYSTEMS

Net meteringThe difference between

production-consumption

is measured

Feed-in tariffThe total production of

energy is measured

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SIMPLIFIED DIAGRAM OF A TYPICAL GRID CONNECTED INVERTER

Self-commutated inverter, with

pulse width modulation and line

frequency transformer

Time

Switches S1,S2 cooperate during one half-period - S3,S4 during next half-period

Pulse width modulationPWM

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PV Power Plant

Large PV power plants

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Large on-grid PV power plants

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Large Scale PV Systems

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PV Residential On-grid PV System / Net-metering (Jordan Example)

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PV Mounting Structures

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• Fixed

• Adjustable tilt (season by season)

• Single axis tracking– Horizontal axis

– Inclined axis

– Vertical axis

• Two or Dual Axis Tracking

Tilt or Inclination Angle Effect

46Reference: PVGIS

92

.5%

95

.0%

97

.1%

98

.6%

99

.7%

10

0.0

%

10

0.0

%

99

.3%

98

.1%

96

.2%

93

.9%

91

.0%

87

.5%

83

.5%

79

.0%

74

.2%

68

.8%

63

.3%

57

.2%

0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

120.0%

0° 5° 10° 15° 20° 25° 30° 35° 40° 45° 50° 55° 60° 65° 70° 75° 80° 85° 90°

Annual Normalized Energy Yield at Different Tilt Angles in Amman - South Facing

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Azimuth or Orientation Angle Effect

47Reference: PVGIS

10

0.0

%

99

.9%

99

.7%

99

.5%

99

.1%

98

.7%

98

.2%

97

.5%

96

.8%

96

.1%

95

.2%

94

.4%

93

.5%

92

.4%

91

.4%

90

.3%

89

.1%

88

.0%

86

.8%

75.0%

80.0%

85.0%

90.0%

95.0%

100.0%

105.0%

0° ±5° ±10° ±15° ±20° ±25° ±30° ±35° ±40° ±45° ±50° ±55° ±60° ±65° ±70° ±75° ±80° ±85° ±90°

Annual Normlalized Energy Yield at Different Azimuth Angles in Amman

Tilt Angle = 28°

South = 0°

East = -90°

West = 90°

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Fixed PV Mounting Structures

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Adjustable Tilt Angle

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Annual Optimum Tilt (Latitude)

Summer Tilt

Winter Tilt

Effect of Tilt Angle on Monthly Averages of Daily Solar Radiation sums

50Reference: PVGIS

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Horizontal Single Axis Tracking

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Vertical Single Axis Tracking

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Inclined Single Axis Tracking

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Dual Axis Tracking

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Yield Comparison Between Fixed and Tracked PV Mounting Stuctures

55Reference: PVGIS

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0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

10

0%

12

2%

12

1%

12

3%

12

6%

13

0% 13

8%

13

5%

13

0%

12

5%

12

3%

12

3%

12

3%

12

7%

11

8%

12

1%

12

5%

12

8%

13

2% 13

9%

13

6%

13

3%

12

8%

12

4%

12

0%

11

9% 1

28

%

12

4%

12

3%

12

5%

12

9% 13

6% 1

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%

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2%

13

5%

12

8%

12

5%

12

5%

12

5%

13

1%

0%

20%

40%

60%

80%

100%

120%

140%

160%

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

Annual Normalized Energy Yield Comparison for Different PV Mounting Structures in Amman

Fixed 28° 1-axis Ver Tilt 50° 1-axis Inc. Tilt 29° 2-axis

Building integrated photovoltaic systems BIPVs

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Building Integrated PV (BIPV)

Thanks

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