Pv solar plant components

Pv solar plant components, solar Power Plant

1. Chapter 4

System Components and
Configurations

Major Components e Balance-of-System
e System Classifications and Designs

© 2012 Jim Dunlop Solar

2. Overview

» Identifying major PV system components and their functions,
including PV modules and arrays, energy storage, power
conditioning equipment and other energy sources.

> Discussing the key trends and sources of U.S. energy supply and
consumption.

> Identifying the key components of the electrical utility system
and the differences between centralized and distributed power
generation.

» Identifying the basic types of stand-alone and interactive PV
systems, their operating principles and major components.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 2

3. >

A Solar Photovoltaic (PV) Systems

ZAS

» Solar PV systems are electrical generators that produce energy for
electrical loads and may interface with other electrical systems.

+: Power
Conditioning Power

Distribution Electrical
ne a, Load
Source

== Load | [AA 0
=
Energy L 4
Conversion |
pr Electric
Utility

1
Energy {
Storage if P
(optional) WA AN

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 3

4. eee

0 à ¡
AD Major System Components

» Photovoltaic (PV) Array
An assembly of PV modules that convert sunlight to DC electricity.

» Power Conditioning Equipment

_ Inverters, chargers and controllers that process DC power from PV arrays
and produce AC power for utilization loads.

> Energy Storage

+ Batteries store energy produced by PV arrays, and are used in most
stand-alone systems, but only in specially-designed grid-tied systems.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 4

5. „DC disconnect
4. Inverter (charger & controller)
5. AC disconnect
6. Utility service panel

7. Battery (optional)

6. nee Balance-of-System Compone

1

> Balance-of-System (BOS) Components
_ Mechanical or electrical equipment and hardware used to assemble and
integrate major components, and to conduct, distribute and control the
flow of power in the system.

> Examples of BOS components include:
Conductors (wiring)

Raceways (conduit)

Junction and combiner boxes

Disconnect switches

Fuses and circuit breakers

Terminals and connectors

Array mounting hardware

+ + + + + + +

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 6

7. ere PV Modules and Arrays

> PV modules are assembled electrically and mechanically to form an
integrated DC power supply.

> An array is the total DC power generating unit designed to produce a
specified electrical output.

PV Module
E

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 7

8. Energy Storage

» Batteries are the primary type of energy storage used in PV
systems, and transform electrical and chemical energy.

> Other types of energy storage systems include:

Flywheels store kinetic energy

Supercapacitors store electrical charge

Fuels store chemical energy

Hydroelectric dams and compressed air systems store potential energy

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 8

9. Batteries

Flooded Lead-Acid

> Batteries are used in most stand-
alone PV systems to store
energy from the PV array and
establish the operating voltage
for DC utilization equipment,
such as inverters or DC loads.

> Lead-acid batteries are the most
common type used in PV
systems.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 9

10. ae Power Conditioning Equipment

ez

» Power conditioning equipment converts, controls or processes
the DC power produced by PV arrays, for interfacing with
electrical loads, utilization equipment or other electrical systems.

» Power conditioning equipment includes:

Inverters

Charge controllers

Battery chargers

DC-DC converters

Maximum power point trackers

+ + + + +

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 10

11. Inverters

> Stand-Alone Inverters
_ Operate from batteries and supply power independent of the utility grid.

> Utility-Interactive or Grid-Connected Inverters
+ Operate from PV arrays and supply power in parallel with the utility grid.

> Bi-Modal or Battery-Based Interactive Inverters

+ Operate as diversionary charge controllers, and produce AC power output
to regulate PV array battery charging when the grid is energized.

+ Transfer PV system operation to stand-alone mode and provide backup
electric power to critical loads when the utility grid is not energized

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 11

12. Inverters

Bi-Modal Inverter

5 Stand-Alone Inverter
Interactive Inverter

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 12

13. 48 V / 40 A Charge Controller

> Acharge controller regulates battery
charging by limiting the charging
current from a PV array, and protects
a battery from overcharge.

> A load controller regulates battery
discharge current by disconnecting
electrical loads, and protects a
battery from overdischarge.

12 V /10 A Charge Controller

> A diversion charge controller
regulates battery charging by
diverting power to a DC diversion
load or grid-connected inverter.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 13

14. Battery Chargers

Integral Inverter/Charger

Many stand-alone inverters have
a built-in battery charger.

Xantrex/Schneider Electric

15. ae Uninterruptible Power Supplies

ez

> An uninterruptible power supply (UPS) is an emergency power
system that supplies electrical loads when the primary source of
power is lost.

> Typically includes a battery, charger, inverter and automatic
transfer switch.

> Grid-connected PV systems with battery storage are a type of

UPS system, transferring loads to the battery-inverter system
when the grid de-energizes.

+ Unlike most UPS systems, the PV array still charges the batteries and
extends load operating time.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 15

16. > Maximum power point trackers
(MPPTs) are electronic devices
that operate PV modules or
arrays at their maximum power
output.

> MPPT functions are included in
all interactive inverters and in

some battery charge controllers.

> Also used at the PV module and
source circuit level for some
applications.

© 2012 Jim Dunlop Solar

Module MPPT

SolarMagic/National Semiconductor

Outback Power Systems

System Components and Configurations: 4 - 16

17. Electrical Loads

» Electrical loads include DC or AC appliances or utilization
equipment that consumes power.

» DC loads typically operate from batteries and are used in some
small stand-alone PV systems, such as for lighting.

> AC loads are powered by inverters, generators or the utility grid.

» Electrical loads are characterized by their operating voltage (AC
or DC), power and energy consumption.

rgy consumption (kWh/day)

power (kW)
t= - load operating time (hrs/day)

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 17

18. Energy Sources

» Basic forms of energy include thermal, chemical, electrical,
kinetic and potential energy sources:
- Solar radiation
_ Fuels (biomass, fossil and alternative fuels)
+ Radioactive materials
+ Hydro and geothermal

» Energy sources can be converted from one form to another with
various energy conversion devices.
+ Steam, combustion and wind turbines
+ Electrical generators
+ Fuel cells
+ PV devices

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 18

19. ie

le}
==
77

J (au

7
=

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 19

20. U.S. Energy Consumption

Consumption
The turning point: production peaks,
consumption exceeds production

\ Production

DOE/EIA

21. D U.S. Energy Flow

Exports?

Goat
arm

| Commercial
Domestic Natural Gas” e
Production 2364 Fossil
mm Sono REE
supply 8525 Æonsumptont
D | 101.60 Industral!
3232

Petroleum!
39.82

Transportation 29.10

| IES ERREET

Renewable Energy’ 683

7

Stock Change
‘and Other
065

Imports Quadrillion Btu [2007]

5:90

DOE/EIA

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 21

22. Natural Gas 7.72

Nuclear Electric Power
841

Renewable Energy 3.92

U.S. Electricity Flow

Energy

Consumed

To Generate
Electricity

42.09 Plant Use® 0 75

JT & D Losses
1.34

GTR Gern End Read
E E i
ue oran te i M

Residential 4.75)

Other
0.17

© 2012 Jim Dunlop Solar

py |

Y
ill Net fmports Trans
Quadrillion Btu [2007] of lecinciy porte
Unacogunted fort 0 i

DOE/EIA

System Components and Configurations: 4 - 22

23. Central Power Generation

» Most power generation is centralized in remote areas and
transmitted over the grid to consumers in population areas. A
large percentage of the energy content in the fuel goes
unutilized.

CO, + Pollution
a” Heat

E> Electricity
Fuel
100%

(Remote from thermal users)
Thomas Casten

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 23

24. Combined Heat and Power

» Combined heat and power (CHP) systems utilize waste heat from
electrical power generation for other purposes.

CO, + Pollution
Aron Wane Hn

Electricity

al
| |
100% CHP Plants u |
=

(located close to thermal users)

Steam

Chilled
Water

Thomas Casten

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 24

25. Electrical Generators

> Most electrical power is
produced from synchronous
generators that are mechanically
driven by turbines or engines.

> A typical generator consists of
an electromagnet, called the field
or rotor, which rotates inside a
coil of wire with an iron core,
called the stator.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 25

26. Engine Generators

> Engine generators use internal
combustion engines to drive
electrical generators, and are
often used in conjunction with
off-grid PV systems.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 26

27. Combustion Turbines

> Combustion turbines are large power generators that are similar
to jet engines.

Caterpillar/Solar Turbines

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 27

28. Microturbines

250 kW Microturbine Engine Cycle

Exhaust Heat
Recuperator

Heat
Exchanger
Combustor

> Gearbox

Compressor
Generator
Air inet a

Ingersoll-Rand

29. Wind Turbines

‘Southwest Windpower

30. Stirling Engines

> Stirling engines use an external heat
source, such as concentrated solar
energy, to compress a gas which
expands to produce mechanical
shaft power to drive an electrical
generator.

NRELBill Timmerman

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 30

31. Fuel Cells

» Fuel cells convert chemical to electrical energy directly. Most fuel
cells combine hydrogen and oxygen to produce heat, water and

DC electricity.
Heat
Hydrogen
Oxygen DC Electricity
Water

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 31

32. > The electric utility system
consists of three principal
parts:

Generation
Transmission
Distribution

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 32

33. Types of PV Systems

» Stand-Alone Systems

4
+
+

Operate autonomously off-grid.
Typically use batteries for energy storage.
Sizing is based on electrical loads.

» Interactive Systems

+

+
+
+

Operate in parallel with the electric utility grid.

Intended to supplement site energy use from utility.

Operation is independent of electrical loads.

Do not generally use batteries or provide backup for utility power.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 33

34. Direct-Coupled

Stand-Alone Systems

» Direct-coupled PV systems are the most basic type of stand-alone
system.

- ADC load is matched and directly connected to a PV module or array.
_ Uses no energy storage.

+ Load only operates when sun is shining.

Water Pump or
Ventilation Fan

PV Array DC Load

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 34

35. ee Stand-Alone PV System
ee L

with Battery Storage

» Most stand-alone PV systems use batteries to store energy
produced by the array for use by loads as required.

» A self-regulating PV system does not use charge control, but the
battery is susceptible to overcharge and overdischarge.

Battery DC Load

Maximum charge must be
limited, typically lower
voltage modules are used.

Battery must be oversized in
relation to PV array charge
rates and daily load energy.

Load must be well-defined,
operate daily and not
subject to user control.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 35

36. pz] Stand-Alone PV Systems

en with Charge Control

» A charge controller is required in most PV systems using

batteries to protect from overcharge and overdischarge, and may
also provide load control functions.

Charge

DC Load
Controller

Battery

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 36

37. ae Stand-Alone PV Systems

en with Charge Control

Charge controller protects battery
from overcharge by PV array

Charge

Controller SELEY

Battery is not protected DC Load
from overdischarge by load.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 37

38. oe Stand-Alone PV Systems with

om Charge and Load Control

This controller This controller
protects battery protects battery
from overcharge from overdischarge

Load
Controller

Charge

Controller DC Load

Battery

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 38

39. pz] Stand-Alone PV Systems with
en Multiple Charge Controllers

Charge Battery
Controller #2

Charge
Controller #3

DC Load or
Inverter
PV Subarray #4

One subarray may be
directly connected to battery
without charge control if
charge rates <= 3% of
battery capacity.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 39

40. oe Stand-Alone PV Systems with

en Diversionary Charge Control

This controller protects the battery when
the diversion load is unavailable

Charge
Controller

Battery

Diversionary controller protects the Di 4 Di 5
battery from overcharge by diverting Iversion Iversion
power to a diversionary load Controller Load

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 40

41. Stand-Alone PV Systems

with AC Loads

Charge
Controller DC Load

Inverter/

Batres Charger

AC Load AC Source
(to Charger Only)

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 41

42. Hybrid System

Charge
Controller DC Load

Battery

Inverter/
Charger

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 42

43. Utility-Interactive PV System

AC Loads

Inverter

Electric
Utility

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 43

44. Utility-Interactive PV System

6 xx with Energy Storage

Backup Primary

AC Loads AC Loads
Bypass circuit

Critical Load Inverter/ À
Sub Panel Charger REI GENE

Charge Electric

ay Control Utility

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 44

45. Bi-Modal System

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 45

46. Summary

» Major components used in PV systems include modules and
arrays, inverters, batteries, chargers and controllers.

> Balance-of-system components include electrical and
mechanical equipment needed to construct a complete PV
system and integrate the major components.

> Stand-alone PV systems operate off-grid and are designed to
power specific electrical loads.

» Interactive PV systems are connected to the utility grid and
supplement site electrical loads.

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 46

47. Questions and Discussion

© 2012 Jim Dunlop Solar System Components and Configurations: 4 - 47