This document provides an overview of solar photovoltaic power systems. It discusses key terminology related to electricity and PV systems. The document describes the main components of grid-tied PV systems including solar modules, inverters, wiring, and batteries. It also covers factors to consider when selecting sites and mounting structures for solar arrays. Overall, the document serves as a basic introduction and reference for understanding the basic workings of grid-tied residential solar power systems.

1. Solar Photovoltaic
Power Plant
Presented By:
Pratish Rawat
Poornima University, Jaipur

5. Making the Change to Renewable
Energy
 Solar
 Geothermal
 Wind
 Hydroelectric

6. Terminology
 Voltage
– Measured in Volts
– Electrical potential
– “Height” of water on one side of a dam compared
to the other side
 Current
– Measured in Amps
– Rate of electron flow
– “Speed” at which water flows through the dam

7. Terminology
 Resistance
– The opposition of a material to the flow of an
electrical current
– Depends on
 Material
 Cross sectional area
 Length
 Temperature

8. Types of Current
 DC = Direct Current
– PV panels produce DC
– Batteries store DC
 AC = Alternating Current
– Utility power
– Most consumer appliances
use AC
– Electric charge changes
direction

9. Terminology
 Watt
– Measure of Power
– Rate of electrical energy
– Not to be confused with Current!

10. Typical Wattage Requirements
Appliance Wattage
Blender 350
TV (25 inch) 130
Washer 1450
Sunfrost Refrigerator (7 hours a
day)
refrigerator/freezer (13 hours a
day)
112
475
Hair Dryer 1000
Microwave (.5 sq-ft)
Microwave (.8 – 1 sq-ft)
750
1400

11. Terminology
 Watt-hour (Wh) is a measure of energy
– Unit quantity of electrical energy (consumption
and production)
– Watts x hours = Watt-hours
 1 Kilowatt-hour (kWh) = 1000 Wh

12. Grid-Tied System Overview

13. Grid-Tied System
 Advantages
– Easy to install
(less components)
– Grid can supply
power
 Disadvantages
– No power if grid goes
down

14. Solar Modules

16. Photovoltaic (PV) Hierarchy
 Cell < Module < Panel < Array

17. Inside a PV Cell

18. Available Cell Technologies
 Single-crystal or Mono-crystalline Silicon
 Polycrystalline or Multi-crystalline Silicon
 Thin film
– Ex. Amorphous silicon or Cadmium Telluride

19. Monocrystalline Silicon Modules
 Most efficient
commercially available
module (11% - 14%)
 Most expensive to
produce
 Circular (square-round)
cell creates wasted
space on module

20. Polycrystalline Silicon Modules
 Less expensive to make
than single crystalline
modules
 Cells slightly less
efficient than a single
crystalline (10% - 12%)
 Square shape cells fit
into module efficiently
using the entire space

21. Amorphous Thin Film
 Most inexpensive
technology to produce
 Metal grid replaced with
transparent oxides
 Efficiency = 6 – 8 %
 Can be deposited on
flexible substrates
 Less susceptible to
shading problems
 Better performance in low
light conditions that with
crystalline modules

22. Selecting the Correct Module
 Practical Criteria
– Size
– Voltage
– Availability
– Warranty
– Mounting Characteristics
– Cost (per watt)

23. Current-Voltage (I-V) Curve

24. Effects of Temperature
 As the PV cell
temperature
increases above 25º
C, the module Vmp
decreases by
approximately 0.5%
per degree C

25. Effects of Shading/Low Insolation
 As insolation
decreases
amperage
decreases while
voltage remains
roughly constant

26. Shading on Modules
 Depends on orientation of internal module
circuitry relative to the orientation of the
shading.
 SHADING can half
or even completely
eliminate the output
of a solar array!

27. Tools
Pyranometer Laser Thermometer
Insolation
Surface
Temperature

28. PV Wiring

30. Series Connections
 Loads/sources wired in series
– VOLTAGES ARE ADDITIVE
– CURRENT IS EQUAL

31.  Loads/sources wired in parallel:
– VOLTAGE REMAINS CONSTANT
– CURRENTS ARE ADDITIVE
Parallel Connections

32. Wiring Introduction
 Should wire in Parallel or
Series?

33. Wire Components
 Conductor material = copper (most common)
 Insulation material = thermoplastic (most common)
 Wire exposed to sunlight must be classed as
sunlight resistant

34. Color Coding of Wires
 Electrical wire insulation is color coded to designate its
function and use
Alternating Current (AC) Wiring Direct Current (DC) Wiring
Color Application Color Application
Black Ungrounded Hot Red (not NEC req.) Positive
White Grounded
Conductor
White Negative or
Grounded
Conductor
Green or Bare Equipment
Ground
Green or Bare Equipment
Ground
Red or any
other color
Ungrounded Hot

35. Cables and Conduit
 Cable: two or more insulated conductors having an
overall covering
 Conduit: metal or plastic pipe that contains wires

36. Wire Size
 Wire size selection based on two criteria:
– Ampacity
– Voltage drop
 Ampacity - Current carrying ability of a wire
 Voltage drop: the loss of voltage due to a wire’s
resistance and length

37. Safety Equipment
 Disconnects  Overcurrent Protection

38. Grounding
 Provides a current path for
surplus electricity to travel too
(earth)

39. Solar Site & Mounting

40. Site Selection – Panel Direction
 Face true
south
 Correct for
magnetic
declination

41. Altitude and Azimuth

42. Solar Pathfinder
 An essential tool in finding a good site for
solar energy is the Solar Pathfinder
 Provides daily, monthly, and yearly solar
hours estimates

43. Site Selection – Tilt Angle
Year round tilt = latitude
Winter + 15 lat.
Summer – 15 lat.
Max performance is
achieved when panels
are perpendicular to the
sun’s rays

44. Solar Access
 Optimum Solar Window 9 am – 3 pm
 Array should have NO SHADING in this
window (or longer if possible)

45. General Considerations
 Weather characteristics
– Wind intensity
– Estimated snowfall
 Site characteristics
– Corrosive salt water
– Animal interference
 Human factors
– Theft protection
– Aesthetics

46. General Considerations Continued
 Loads and time of use
 Distance from power conditioning equipment
 Accessibility for maintenance

47. Basic Mounting Options
 Fixed
– Roof, ground, pole
 Integrated
 Tracking
– Pole (active & passive)

48. Pole Mount Considerations
 Ask manufacturer for wind loading
specification for your array
– Pole size
– Amount of concrete
– Etc.
 Array can be in close proximity to the house,
but doesn’t require roof penetrations

49. Tracking Considerations
 Can increase system performance by:
– 15% in winter months
– 30% in summer months
 Adds additional costs to the array

50. Passive Vs. Active
Active:
– Linear actuator
motors controlled by
sensors follow the
sun throughout the
day

51. Passive Vs. Active
Passive:
– Have no motors,
controls, or gears
– Use the changing
weight of a gaseous
refrigerant within a
sealed frame
member to track the
sun

52. Roof Mount Considerations
 simple and cheap to
install
 offer no flexibility in
the orientation of
your solar panel
 can only support
small photovoltaic
units.

53. Roof Mount Considerations
 Penetrate the roof as little as possible
 Weather proof all holes to prevent leaks
– May require the aid of a professional roofer
 Re-roof before putting modules up
 Leave 4-6” airspace between roof and
modules
 On sloped roofs, fasten mounts to rafters not
decking

54. Costs

55. Solar Energy Incentives
 Tax credits and deductions
– 30% tax credit
 Local & state grant and loan programs
 PA Alternative Energy Investment Fund
– Pennsylvania Sunshine Program
 35% rebate

56. Energy Efficiency

57. Improving Energy Efficiency in the
Home
 Space Heating:
– Insulation
– Passive solar design
– Wood stoves
– Propane
– Solar hot water
– Radiant Floor/
baseboard
– Efficient windows
 Domestic hot water
heating
– Solar thermal
– Propane/natural gas
– On demand hot water

58. Improving Energy Efficiency in the
Home
 Washing machines
– Energy efficient front
loading machine
 Cooling
– Ceiling fans
– Window shades
– Insulation
– Trees
– Reflective attic cover
– Attic fan

59. Lighting Efficiency
 Factors effecting light efficiency
– Type of light
– Positioning of lights
– Fixture design
– Color of ceilings and walls

60. Incandescent Lamps
 Advantages
– Most common
– Least expensive
– Pleasing light
 Disadvantages
– Low efficiency
– Short life ~ 750 hours
Electricity is conducted through a filament which resists
the flow of electricity, heats up, and glows
Efficiency increases as lamp wattage increases
FROM THE POWER PLANT TO YOUR HOME
INCANDESCENT BULBS ARE LESS THAN 2%
EFFICIENT

61. Fluorescent Bulbs
 Less wattage, same amount of lumens
 Longer life (~10,000 hours)
 May have difficulty starting in cold
environments
 Not good for lights that are repeatedly turned
on and off
 Contain a small amount of mercury

62. Light Emitting Diode (LED) Lights
 Advantages
– Extremely efficient
– Long life (100,000 hours)
– Rugged
– No radio frequency
interference
 Disadvantages
– Expensive (although
prices are decreasing
steadily)
– A relatively new
technology

63. Grid-Tied System
 Advantages
– Low: Easy to install
(less components)
– Grid can supply
power
 Disadvantages
– No power when grid
goes down

64. Batteries in Series and Parallel
 Series connections
– Builds voltage
 Parallel connections
– Builds amp-hour capacity

65. Battery Basics
 Battery
 A device that stores electrical energy (chemical energy to
electrical energy and vice-versa)
 Capacity
 Amount of electrical energy the battery will contain
 State of Charge (SOC)
 Available battery capacity
 Depth of Discharge (DOD)
 Energy taken out of the battery
 Efficiency
 Energy out/Energy in (typically 80-85%)
The Terms:

66. Functions of a Battery
 Storage for the night
 Storage during cloudy weather
 Portable power
 Surge for starting motors
**Due to the expense and inherit inefficiencies of batteries it is
recommended that they only be used when absolutely necessary (i.e.
in remote locations or as battery backup for grid-tied applications if
power failures are common/lengthy)

67. Batteries: The Details
 Primary (single use)
 Secondary (recharged)
 Shallow Cycle (20% DOD)
 Deep Cycle (50-80% DOD)
Types:
 Unless lead-acid batteries are charged up to 100%, they will loose
capacity over time
 Batteries should be equalized on a regular basis
Charging/Discharging:

68. Battery Capacity
 Amps x Hours = Amp-hours (Ah)
Capacity:
100 amps for 1 hour
1 amp for 100 hours
20 amps for 5 hours
 Capacity changes with Discharge Rate
 The higher the discharge rate the lower the capacity and vice versa
 The higher the temperature the higher the percent of rated capacity
100 Amp-hours =

69. Grid-Tied System
(With Batteries)
 Complexity
– High: Due to the
addition of batteries
 Grid Interaction
– Grid still supplements
power
– When grid goes down
batteries supply power
to loads (aka battery
backup)

70. Controllers & Inverters

71. Grid-Tied System
 Advantages
– Low: Easy to install
(less components)
– Grid can supply
power
 Disadvantages
– No power when grid
goes down

72. Controller Basics
 To protect batteries from being overcharged
Function:
 Maximum Power Point
Tracking
– Tracks the peak
power point of the
array (can improve
power production by
20%)!!
Features:

73. Additional Controller Features
 Voltage Stepdown Controller: compensates for differing
voltages between array and batteries (ex. 48V array
charging 12V battery)
– By using a higher voltage array, smaller wire can be
used from the array to the batteries
 Temperature Compensation: adjusts the charging of
batteries according to ambient temperature

74. Other Controller Considerations
 When specifying a controller you must consider:
– DC input and output voltage
– Input and output current
– Any optional features you need
 Controller redundancy: On a stand-alone system it might
be desirable to have more then one controller per array in
the event of a failure

75. Inverter Basics
 An electronic device used to convert direct current (DC)
electricity into alternating current (AC) electricity
Function:
 Efficiency penalty
 Complexity (read: a component which can fail)
 Cost!!
Drawbacks:

76. JAWAHARLAL NEHRU NATIONAL
SOLAR MISSION
 Make India a global leader in solar energy and the mission
envisages an installed solar generation capacity of 20,000
MW by 2022, 1,00,000 MW by 2030 and of 2,00,000 MW by
2050.
 The total expected investment required for the 30-year period
will run is from Rs. 85,000 crore to Rs. 105,000 crore.
 Between 2017 and 2020, the target is to achieve tariff parity
with conventional grid power and achieve an installed
capacity of 20 gigawatts (Gw) by 2020.
 4-5 GW of installed solar manufacturing capacity by 2017.
 To deploy 20 million solar lighting systems for rural areas by
2022

77. JAWAHARLAL NEHRU NATIONAL
SOLAR MISSION

82. 100 KW Rooftop Solar
Power Plant
Installed at Poornima University

83. Specification of Solar PV Module
MODEL ELDORA 300P
Make Vikram Solar
Maximum Power 300 W
Open Circuit Voltage 45.1 V
Short Circuit Current 8.74 A
Maximum Current 8.05 A
Maximum Voltage 37.28 V
Efficiency 15.63 %
Fill Factor 76.13%
NOCT 45 0 C
Number of Panels 334

84. Specification of Solar Inverter
Model STP 25000TL-30
Make SMA
Number of Inverter 04
V (DC, maximum) 1000 V
I (DC, maximum) 33A
V (DC, max. power point) 390-800 V
I (SC, PV) 43 A
Power 25 kVA
I (AC, maximum) 36.2 A

85. Power Generation (Trial Run)
Date Daily Power Generated
(kWh)
8:30 am to 4:30 pm
Total Power Generation
(kWh)
04/01/2016 (Plant Starts) 74.29 74.29
05/01/2016 414.71 489.00
06/01/2016 617.75 905.75
07/01/2016 391.43 1234.52
08/01/2016 426 1660
09/01/2016 378.06 2028.50
10/01/2016 433.56 2462.06
11/01/2016 406.86 2868.92

86. Glimpse of installation of 100 KW
Rooftop Solar Power Plant

87. Glimpse of installation of 100 KW Solar
Power Plant

88. 100 KW ROOF TOP SOLAR
POWER PLANT
 Capacity of Plant: 100 KW
 Cost of Plant: 79.49 Lacs
 Date of Production: Wednesday, February 10, 2016
 Daily Power Generation: 400-450 KWH (On
Sunny Days)
 Annual Power Generation:1,50,000 Units

89. Thank You