Solar Energy by EcoOne Homes

1. 1
Solar Photovoltaic Technologies, Applications and Why Solar Now ?
David Pham

2. 2
Photovoltaic Solar System categoriesPhotovoltaic Solar System categories
Residential < 15kW
Commercial > 15kW
Some commercial projects require ARRA
Government > 15kW meets ARRA
American Recovery & Reinvestment Act (ARRA)
Proudly made in the USA
Utility > 1MW
Some projects require ARRA

3. 3
Grid Tied PV System Outline – Facing South @ 30 degree Tilt in Central Texas

4. 4
Yearly Sum of Global Irradiance
Solar Irradiance : Total amount of solar radiation per unit area
Germany
USA
From 2004 to 2010: ~60% of all solar modules made world wide were consumed by Germany. Less
than 1% were consumed by the USA. Germany has nearly half the world's installed solar cell capacity,
thanks to a generous national policy feed in tariff program.

5. 5
Photovoltaic (PV) Solar Energy statistics, factsPhotovoltaic (PV) Solar Energy statistics, facts

6. 6
Photovoltaic (PV) Solar Energy statistics, factsPhotovoltaic (PV) Solar Energy statistics, facts
• The Earth receives more energy from the sun in an hour than is used in the entire world in one
year.
• It would take only around 0.3 per cent of the world's land area to supply all of our electricity needs
via solar power.
• According to the United Nations 170,000 square kilometers of forest is destroyed each year. If we
constructed solar farms at the same rate, we would be finished in 3 years.
• Wind is a form of solar power, created by the uneven heating of the Earth's surface.
• 92 Square Miles of Solar Photovoltaic (PV) could power the entire USA. ~ ¼ Size of DFW 385
sqm.
• The first solar cell was constructed by Charles Fritts in the 1880s - it had a conversion efficiency of
just 1%. In 2014 a C-Si solar cell made by SunPower (USA company 2007) has 25% efficiency.
Theoretical maximum efficiency for a C-Si solar cell is 29%.
• Weight for weight, advanced silicon based solar cells generate the same amount of electricity over
their lifetime as nuclear fuel rods, without the hazardous waste. All the components in a solar panel
can be recycled, whereas nuclear waste remains a threat for thousands of years.
• Manufacturing solar cells produces 90% less pollutants than conventional fossil fuel technologies.
• The solar industry creates 200 to 400 jobs in research, development, manufacturing and installation
for every 10 megawatts of solar power generated annually.

7. 7
GO SOLARGO SOLAR
Tom Brady and Gisele Bundchen‘s Residence
Solar System

8. 8
w/o Solar System electric bill- residential
Year
$
Rate Increase 7% per year
Today $250/month @ $0.13 per kWh

9. 9
Utility Companies INCREASING Rate
From Austin Energy

10. 10
Utility Companies Decreasing CO2 Emission
From Austin Energy

11. 11
Lights-On 2007

12. 12
Lights-On ~2030

13. 13
Utility Companies Promoting Renewable Energy SOLAR
From Austin Energy

14. 14
Solar System Adds A Premium To a Home’s Resale Value
“The exact numbers vary from property to
property and installation to installation, but
recent research shows an average
increase in resale value being $5,911 for
each 1 kilowatt (kW) of solar installed.”
(costofsolar.com) March 2014

15. 15
How Tough are Solar Modules
Study:
Jet Propulsion Laboratories (JPL)
Pasadena, California
“* Hail Impact with a 1 in ice
ball traveling at a terminal
velocity of 52 mph *”
• All Solar Modules have a 25 years
Warranty
• At 25 years the Solar Modules still
have an output > 80% of original
specification

16. 16
Investment Comparison Risks and Returns

17. 17
How to read your electric bill ?
In Nov-Dec = 850 kWh
Cost per month from 850 kWh + fees = $110.90
Cost per kWh = $110.90 / 850 kWh = 0.13 $/ kWh
Do this for every month and take the average kWh, cost and $/kWh

18. 18
Calculate How Much Solar Do I Need ?
Ave. kWh use/month (from your 12 months electric bills) a) 2,500
kWh x 1000 = AC Watts/month = a x 1000 b) 2,500,000
AC Watts used per day = b/30.5 (days in a month) c) 81,967
AC Watts used per day/Sun Hours per day (TX = 5.4) = c / 5.4 d) 15,179
DC Watts needed per hour per day = d x 1.29 e) 19,581
Solar array to ZERO electric bill in DC Watts f) 19,581
Solar Array in KiloWatts, or kW DC = f / 1000 g) 19.581
Solar Array in KiloWatts DC = kW DC (round up) h) 20.00
We want to 50% the cost = 20 kW DC x .05 = 10 kW DC

19. 19
How much money can I save from my Solar System ?
http://pvwatts.nrel.gov/

20. 20
How much money do I have to spend ?
Avg./month
~$250
Increasing
Every
Year
NO Solar
Lender
(Bank, Family,etc..)
Avg./month
~$125
Increasing
Every Year
YES Solar
X
Solar
Saving
~4-6 years ROI
$
Solar Loan
Solar Cost
Utility
rebate,
Fed. Tax
rebate,
Deprec.,
State Tax
Incentives
$$$$$
Solar
Out of
Pocket

21. 21
Why Solar Now ?
Incentive Programs for Distributed PV Solar System Soon to be phased-out
•Local Utility Value of Solar Energy Feed in Tariff (FIT) (Local Utility)
•Local Utility Rebate Residential (Local Utility)
•Performance Base Incentive for Commercial (Local Utility)
•30% Federal Tax Rebate (USA) Ending 2016
•5 year depreciation Federal Tax Savings (USA) – Commercial projects
•Texas Franchise Tax (corporate tax) savings (Texas) – Commercial projects
Facing South @ 30 degree tilt angleFacing South @ 30 degree tilt angle
All Local Utility Rebates can
be phased out at any time
by the Utility Companies.

22. 22
Return on Investment (ROI) and Rate of Return (ROR) – Example 70kW DC
ROI
ROR
Rebate & Incentives
Commercial Solar System – Please consult your CPA or qualified tax consultant for more details.

23. 23
Return on Investment (ROI) and Rate of Return (ROR) – Example 10kW DC
ROI
ROR
Rebate &
Incentives
Residential Solar System – Please consult your CPA or qualified tax consultant for more details.

24. 24
Economic Impact of Renewable Energies in the USA
Study Finds U.S. Solar Jobs Grew Nearly 20% In 2013, solar
employers are optimistic about 2014, expecting to add another
22,000 jobs over the coming year.
by Solar International Staff on Monday 27 January 2014

25. 25
Carbon Dioxide (CO2) Concentration vs. Temperature Change
Concentrations of
atmospheric greenhouse
gases (mostly CO2) and
their radiative forcing
have continued to
increase as a result of
human activities. - Third
Assessment Report of
the IPCC, 2001

26. 26
Environmental Benefits of a 71kW PV System in Houston, TX

27. 27
Why Solar Energy and Wind Power?
Reverse CO2 pollution
• Future for your family
Energy Independence
• Displaces natural Gas
• Reduce import of foreign Oil
• Endless supply of SUN ENERGY
Electricity Prices/Save/Earn money
Increase property Value
Energy Security
• Stabilizes grid by reducing peak power demand
$$$$ save

28. 28
Win – Win - Win
Win – USA – Stimulate the Economy, Oil dependence, etc..
Win – Earth – A step in helping to reduce CO2 pollution
Win – You & Family – Save Money, Increase Property Value, etc…

29. 29
Gift
Solar Energy and Energy Efficiency Audit:
Usually, the Solar Energy and Energy Efficiency Audit of a Commercial building costs $250, and costs $150 for a residential. With
this voucher you have a chance to receive this service for FREE with NO OBLIGATION.
As part of the Solar Energy and Energy Efficiency Audit, our professional team of auditors will:
1) Give the property a review, looking for drafts, leaks, and other things that could lead to increased energy usage.
2) Review your electricity payment monthly for a proposal to zero-out or decrease this payment using latest technology solar
photovoltaic system and energy efficiency package.
We will help you to maximize your property energy efficiency with an energy efficiency package including solar photovoltaic energy
system thus lower or zero-out the monthly electrical bill. There are solar renewable energy rebates from the Federal Government and
the energy companies that will soon be phased-out. We will help you to take advantage of these rebates and have the government
and the energy company to pay for more than 50% of the cost for the property to be energy independent.
Gift for your
Interest in Solar RE

30. 30
Photovoltaic Solar Cell TechnologiesPhotovoltaic Solar Cell TechnologiesSourceECN,Petten.nl

31. 31
Thin Film PV
Commercially C-Si & Thin Film Photovoltaic
Technology Type Appearance Cell
Efficiency
Module
Efficiency
Amorphous
Silicon Thin Film
Flexible / Rigid 7% - 10% 7% - 10%
CdTe Thin Film
(Cadmium Telluride)
Flexible / Rigid 9% - 11% 9% - 11%
CIGS Thin Film
(Copper Indium Gallium
Selenide)
Flexible / Rigid 10% - 12% 10% - 12%
Multi-Crystalline
Silicon Cell
Conventional
& Selective
Emitter
14% - 17% 12% - 15%
Mono-Crystalline
Silicon Cell
Conventional
& Selective
Emitter
15% - 19% 13% - 17%
Metal Wrap
Through C-Si
MWT 16% - 20% 14% - 18%
Emitter Wrap
Through C-Si
EWT 17% - 22% 15% - 20%
Inter-Digitated
Back Contact C-Si
IBC 22% - 24% ~+20%
C-Si PV
High EfficiencyHigh Efficiency
C-Si PVC-Si PV

32. 32
PV C-Si & Thin Film Chain of Production to Installation
Crystalline Silicon Chain of Production to Installation –
(Residential / Commercial / Utility (IBC))
Wafer
production
(Silicon to Wafer)
Factory 1
Cell
Manufacturing
(Wafer to Cell)
Factory 2
Module
Manufacturing
(Cell to Module)
Factory 3
Cell-Module
Manufacturing
(Materials to Module)
Factory 1
Thin Film Chain of Production to
Installation - (Commercial/Utility)

33. 33
Commercially C-Si vs. Thin Film Photovoltaic
C-Si Solar Thin Film Solar
High power to area ratio (smaller
array for same output)
Lower output to area ratio (larger
array for same output)
Higher cost of technology Lower cost of technology
Lower cost of installation Higher cost of installation (larger
array therefore more labor and
materials required for the
installation)
Requires installation in areas not
subject to shading
Able to operate in greater light
range and with partial shading of
the array
More suitable to temperate
climates
Ability to perform well in extreme
heat
Green = pros black = cons
>95% Residential

34. 34
C-Si (Crystalline Silicon) Solar Cell Processing
Ag/Al sreen-printed Crystalline Silicon (C-Si) Photovoltaic (PV) solar cells
Electrons (-) charge
Holes
Holes (+) charge
_
+
DC
Theoretical limiting Max-efficiency of C-Si Solar cell = 29%
N- type = doped Silicon with Phosphorus PH3 (phosphine gas) = rich in electrons (-)
P- type = doped Silicon with Boron B2H6 (diborane gas) = rich in holes (+)

35. 35
C-Si Multi (Poly) Solar Cells (Ag FS, Ag BS Tabbing, Al BSF)
Front Back
Cell Thickness = 120 um lower grade silicon with more impurity

36. 36
Mono-Crystalline Solar Cell (Ag FS, Ag BS Tabbing, Al
BSF)
Front Back
Cell Thickness = 120 um higher grade silicon with less impurity

37. 37
Al ink forms full covered back electrode and provides passivation.
Ag(Al) tabbing ink provide the soldering for module assembly
C-Si Solar Cell Contact Formation and Metallization Process
 Step 1. Contact Formation
Solar Wafer
PH3 doped +
SiN APCVD
Front grid
print and
dry
Rear Ag/Al
and Al print
and dry
Flip
≥80o
C/sec
600o
C→800o
C
≥80o
C/sec
800o
C→600o
C
Drying Firing
Cross
section P-Type Silicon
PH3 doped N-Type Emitter
Ag (frits)
Ag/Al
Al
Al(BSF)
Co-fire
 Step 2. Rapid Thermal Process (RTP)
SiN AntiReflective layer
Heat ~800 C

38. 38
C-Si PV SE X-Section:
C-Si Selective Emitter (SE) (part 1) conventional Ag FS, Ag BS Tabbing, Al BSF
Cross Section
P-Type Silicon
N-Type Emitter
N ++ SE

39. 39
Selective Emitter (SE) Process
 Selective Emitter Process - Why SE is being used?
0
20
40
60
80
100
300 500 700 900 1100
Wavelength (nm)
IQE(%)
Spire : 60 Ohm/sq
Spire : 80 Ohm/sq
Increased energy from blue (UV) light

40. 40
C-Si Multi-crystalline Solar Module
156mm×156mm 72(6×12pcs)
Multi-Crystalline cells in a module
Module Multi-Crystalline Module
Encapsulation Glass/EVA/Cells/EVA/TPT
Size and Number of cells 156mm×156mm 72 (6×12pcs)
Maximum power Wp 230Wp
Maximum power voltage(Vmp)V 35.28V
Maximum power current(Imp)A 6.52A
Open circuit voltage(Voc) V 43.92V
Short circuit current(Isc) A 7.26A
Model size(mm) mm 1956×992×50
Weight Kg 23.0Kg
Operating Temperature °C -40°C to+85°C
Warranty 25 years
SunTech’s 230 Wp Multi-C Module (made in China)

41. 41
C-Si Mono-crystalline Solar Module
125mm×125mm 72 (6×12pcs) Mono-
Crystalline cells in a module
Module Mono-Crystalline Module
Encapsulation Glass/EVA/Cells/EVA/TPT
Size and Number of cells 125mm×125mm 72 (6×12pcs)
Maximum power Wp 180Wp
Maximum power voltage(Vmp)V 35.65V
Maximum power current(Imp)A 5.05A
Open circuit voltage(Voc) V 44.28V
Short circuit current(Isc) A 5.60A
Model size(mm) mm 1580×808×45
Weight Kg 15.5Kg
Operating Temperature °C -40°C to+85°C
Warranty 25 years
Advanced Solar Photronic’s (all American made)
180 Wp Mono-C Module

42. 42
Traditional C-Si Module Manufacturing Process – LABOR INTENSIVE
In actual use, cells are connected in series,
to accumulate sufficient voltage from the
0.6V that a standard cell delivers to deliver
usable voltage levels. Industrial grade solar
modules are built from individual cells,
interconnected with wiring and sandwiched
between glass plates and polymer films for
protection.
Cells
Encapsulation of a cell string into a module. From top to
bottom: tempered glass sheet, EVA encapsulant, solar
cells, EVA encapsulant and tedlar back-sheet foil.
EVA
EVA (EthyleneVinylAcetate)
GLASS
TEDLAR
Dupont
Module Efficiency < 18%
High Failure Rate
Requires Visual Inspection
65% of module mfg cost

43. 43
Traditional C-Si Module Manufacturing Process – LABOR INTENSIVE

44. 44
C-Si Module and operation
a. Solar Cell
b. In a module, cells are usually connected in series
P type silicon
Al(BSF)
Ag front
conductor
Neg. charge
Ag back
Conductor
Pos. Charge
Tabbing-String interconnected
Tin (Sn) coated Copper (Cu) Wire
Solar
Radiation
shadow
N type emitter
Al reflector
SiN (silicon nitride) anti-reflective coating (ARC)
Decrease performance of the solar modules

45. 45
IBC Inter-Digitated Back Contact C-Si Solar Cell
Advanced Solar Cell
Inter-Digitated Back Contact (IBC)
SunPower (Cypress Semiconductor) – USA company
Headquarter – San Jose, California
Manufacturing plants in – 2 Taiwan, 2 Malaysia, 3 Philippines
Original application for CPV

46. 46
Inter-Digitated Back Contact (IBC) C-Si PV:
Inter-Digitated Back Contact (IBC) C-Si Solar Cell
Cu
USA Patent – Back Contact Solar Cell and Method of Manufacture
William P. Mulligan, Michael J. Cudzinovic – SunPower Corporation
Pub No: US 7,339,110 B1 Date: March 4, 2008
Cu electroplate + Al/TiW/Cu barrier metal semiconductor
processes

47. 47
Back Contact C-Si Solar Cells Metal Wrap-Through (MWT)
Contact diameter ~ 1 mm

48. 48
EWT Back Contact C-Si PV cell:
Back Contact C-Si Solar Cells Emitter Wrap-Through (EWT)
USA Patent – Contact Fabrication of Emitter Wrap-Through Back Contact Silicon Solar Cell
Peter Hacke & James M. Gee – Applied Materials Inc
Pub No: US 2011/0086466 A1 Date: April 14, 2011
SEM images

49. 49
C-Si Processing Back Contact Solar Cell (SunPower, AMAT)
Mono-Crystalline IBC
Back Contact cell
SunPower Corporation
Multi-Crystalline EWT
Back Contact cell
Applied Materials/Advent Solar

50. 50
IBC, MWT, EWT C-Si PV Pick & Place automated BC Module process:
EWT, MWT, I BC Back Contact C-Si PV Module
BackSheet Circuit Board by Applied Materials
MWT module Efficiency > 18%
EWT module Efficiency > 19%
IBC module Efficiency > +21%

51. 51
Back Contact C-Si Solar Metal Wrap-Through (MWT) PV module
Images from Solland Solar
Pick and place back contact module
No front string ribbon wires
Low failure rate

52. 52
Photovoltaic Thin Film Solar Cell TechnologiesPhotovoltaic Thin Film Solar Cell Technologies

53. 53
Thin Film PV Technologies (Amorphous Si, CIS/CIGS, CdTe, Organic)

54. 54
Amorphous Silicon Thin Film Solar Module Cross Section
~10% Efficiency

55. 55
CdTe Thin Film Module Cross Section
Tin Oxide – Trans. conductive Oxide
Soda lime Glass Substrate
Glass Substrate
ZnTe
Mo
CdTe
CdS
ZnO
TCO
Glass Front
Transparent
Front Contact
200 nm
Metallic Back
Contact 200 nm
P-doped (absorber) 4-10 um
N-doped (window layer) 100 nm
Cadmium Telluride (CdTe) Thin Film Solar
Phoenix, AZ
~12% Efficiency

56. 56
CIGS Thin Film Module Cross Section
P-Type
N-Type
Austin, TX
Copper Indium Gallium Selenide (CIGS) Thin Film Solar
~14% Efficiency

57. 57
Basic Photovoltaic System (Cell to Module)
Solar Cell: The basic photovoltaic device that is the building block for PV
modules.
Connect Cells To Make Modules. One silicon solar cell produces ~ 0.5 volt.
36 cells connected together have enough voltage to charge 12 volt batteries
and run pumps and motors. 72-cell modules are the new standard for grid-
connected systems having a nominal voltage of 24-Volts and operating at
about 30 Volts. Modules listed to UL1703/UL1730
At 25 years manufacture warranty on solar modules.

58. 58
Basic Photovoltaic System (Module in Series, String in Parallel )
Modules in Series
Voltage (V) = Increases
Current (I) = same
-
+
-
+
-
+
- -
-+ +
+
+
-
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
24VDCnominal
4.4Amps
1 2 3
2 Modules in Series in String 1, 2, and 3
Voltage (V) = 24 VDC x 2 = 48 VDC
Current (I) = 4.4 Amps
3 Strings in a Parallel PV Array
Voltage (V) = 48 VDC
Current (I) = 4.4 Amps x 3 = 13.2 Amps
Modules in Parallel
Voltage (V) = same
Current (I) = increases
48 VDC @ 13.2 Amps

59. 59
Residential use
Single-phase (3kW - 10kW) DC/AC mounted inverter
Direct Current (DC) to Alternating Current (AC) Inverters
DC to AC Power conversion
3-phase (50kW – 500kW) DC/AC
central inverter
3-phase (3kW -30kW) DC/AC inverter
Commercial/Utility use

60. 60
AC Solar Panel with DC-AC Micro-Inverter build-in
Panel level DC to AC power
conversion. Maximum
Panels Per Branch Circuit is
17 panels
Benefits:
•Simplifies system design, with panel level DC to AC power conversion
•Improves your energy harvest, with power optimization at the panel level
•Enables detailed energy monitoring of each individual panel
Headquarter in Austin, TX

61. 61
Grid Tied PV System Outline – Facing South @ 30 degree Tilt in Central Texas

62. 62
Grid Tied PV System Outline
Facing South @ ~ 30 degree Tilt in Central Texas

63. 63
Basic Grid Tied PV System w/o Battery Backup
Most Popular
configuration
Residential & Commercial

64. 64
Grid Tied PV System with Battery backup
A charge controller, sometimes referred to as a photovoltaic controller or
battery charger, is only necessary in systems with battery back-up
Charge controllers are selected based on:
 PV array voltage – The controller’s DC voltage input must match the nominal
voltage of the solar array.
 PV array current – The controller must be sized to handle the maximum
current produced by the PV array.

65. 65
Off Grid PV System with Battery Bank
Weak point

66. 66
Basic Photovoltaic System (Module to System)
PV Module is the basic building block of systems. Can connect modules together
to get any power configuration. Listed to UL 1703/1730.
PV Array is a number of modules connected in series strings connected in parallel.
PV System includes PV modules, Inverters, (perhaps batteries) and all associated
installation & Control components
On-grid system
Grid-tied
Grid-connected
Utility-interactive
Grid-interactive
Interactive-system
Off-grid
Stand -alone

67. 67
Balance of Systems (BOS)
BOS listed to UL1741
DC Solar Disconnect
DC to AC Solar Inverter
Solar Meter
AC Solar Disconnect
Internet Service Box from 3rd
party
AC House Mains Panel
Usage Meter

68. 68
Why Solar Now ?
Incentive Programs for Distributed PV Solar System Soon to be phased-out
•Local Utility Value of Solar Energy Feed in Tariff (FIT) (Local Utility)
•Local Utility Rebate Residential (Local Utility)
•Performance Base Incentive for Commercial (Local Utility)
•30% Federal Tax Rebate (USA) Ending 2016
•5 year depreciation Federal Tax Savings (USA) – Commercial projects Ending 2016
•Texas Franchise Tax (corporate tax) savings (Texas) – Commercial projects
Facing South @ 30 degree tilt angle

69. 69
Investment Comparison Risks and Returns

70. 70
Return on Investment (ROI) and Rate of Return (ROR) – Example 70kW DC
ROI
ROR

71. 71
Win – Win - Win
Win – You & Family – Save Money, Increase Property Value, etc…
Win – USA – Stimulate the Economy, Oil dependence, etc..
Win – Earth – A step in helping to reduce CO2 pollution

72. 72
Environmental Benefits of a 10kW PV System in Austin, TX

73. 73
GO SOLARGO SOLAR
Tom Brady and Gisele Bundchen‘s Residence
Solar System

74. 74
Gift
Solar Energy and Energy Efficiency Audit:
Usually, the Solar Energy and Energy Efficiency Audit of a Commercial building costs $250, and costs $150 for a residential. With
this voucher you have a chance to receive this service for FREE with NO OBLIGATION.
As part of the Solar Energy and Energy Efficiency Audit, our professional team of auditors will:
1) Give the property a review, looking for drafts, leaks, and other things that could lead to increased energy usage.
2) Review your electricity payment monthly for a proposal to zero-out or decrease this payment using latest technology solar
photovoltaic system and energy efficiency package.
We will help you to maximize your property energy efficiency with an energy efficiency package including solar photovoltaic energy
system thus lower or zero-out the monthly electrical bill. There are solar renewable energy rebates from the Federal Government and
the energy companies that will soon be phased-out. We will help you to take advantage of these rebates and have the government
and the energy company to pay for more than 50% of the cost for the property to be energy independent.
Gift for your
Interest in Solar RE

75. 75
Photovoltaic C-Si Solar Cells ManufacturingPhotovoltaic C-Si Solar Cells Manufacturing
SourceECN,Petten.nl

76. 76
Environmental Benefits of a 10kW PV System in Austin, TX

77. 77
C-Si, TF cells and modules
Conventional C-Si PV
Mono - Multi
Conventional C-Si PV
Selective-Emitter
Back Contact C-Si PV
EWT, MWT, IBC
TF CdTe PV
Flex
TF CdTe PV
Rigid
Back Contact C-Si PV
IBC Module
TF CIGS PV
Flex
TF CIGS PV
Rigid
TF A-Si PV
Flex
TF A-Si PV
Rigid
Organic TF PV
Module
Residential
Commercial / Utility
Residential <15 kW
Commercial / Utility > 15 kW
Largest in US 2014 utility 400 MW
CPS energy San Antonio, TX
As of April 2013, the largest individual photovoltaic (PV) utility power
plants in the world is Agua Caliente Solar Project, (Arizona, over 251 MW,
397 MW DC when completed)

78. 78
Photovoltaic Power Equations for C-Si Solar Cells
Metal Interconnect
Current Flow
Solar Active Area
Emitter
Diffusion
Finger
Metal
+
-
+ -
+
- + -
+
-
Current Flow
Flow Through MetalPower = I2
R = I2
* (Re + Rc + Rf + Rbb)
Re= emitter resistance = Sheet Resistance * L/W
Rc = contact resistance = Contact R * area metal
Rf = metal resistance finger = sheet resistance * (metal length/metal width)
Rbb = bus bar resistance = sheet resistance* (metal length/metal width)
W
L
Schematic symbol of solar cell

79. 79
Selective Emitter (SE) C-Si PV process:
C-Si Selective Emitter (SE) (part 2)
Selective Emitter is to increase cell efficiencies for both mono- and multi
crystalline cells by up to as much as 1 percent in absolute terms
Key to performance is reducing losses (Rs & Rsh)

80. 80
Photovoltaic Power Equations (all solar cells)
Efficiency η, “Eta“ - A solar cell's energy conversion efficiency is the percentage of power
converted (from absorbed light to electrical energy) and collected, when a solar cell is connected
to an electrical circuit. This term is calculated using the ratio of the maximum power point, PM,
divided by the input light irradiance (E, in W/m2) under standard test conditions (STC) and the
surface area of the solar cell (AC in m2).(Higher is betterHigher is better)
Fill factor (FF) - Another defining term in the overall behavior of a solar cell is the fill factor (FF).
This is the ratio of the maximum power point divided by the open circuit voltage (Voc) and the
short circuit current (Isc). The fill factor is directly affected by the values of the cells series and
shunt resistance. Increasing the shunt resistance (Rsh) and decreasing the series resistance (Rs)
will lead to higher fill factor, thus resulting in greater efficiency, and pushing the cells output power
closer towards its theoretical maximum. (Higher is better)Higher is better)
JSC = Short Circuit current density
PM = Peak Power –Pmax
VOC = Voltage Open Circuit
ISC = Current Short Circuit
RS = Resistance Series
I = Output current (amperes)
IL = Photo-generated current (amperes)
ID = Diode current (amperes)
ISH = Shunt current (amperes)
RSH = Shunt resistance
I = IL − ID − ISH

81. 81
Photovoltaic – Electrical Properties
Rs = Rbulk Si + Remitter + Rcontact + Rgrid line + Rbus bar
Key to performance is reducing losses (Rs & Rsh)

82. 82
IBC C-Si PV processes:
Inter-Digitated Back-Contact (IBC) Metallization formation
Silicon Substrate
Aluminum (Al) Layer
Titanium-tungsten (TiW) Layer
Copper (Cu) Seed Layer
Copper Layer Copper Layer Copper LayerCopper Layer
Tin (Sn) Layer Tin (Sn) LayerTin (Sn) Layer Tin (Sn) Layer
PR
N-TypeSilicon Substrate
Silicon dioxide
(SiO2)
Silicon dioxide
(SiO2)
Silicon dioxide
(SiO2)
Silicon dioxide
(SiO2)
Aluminum (Al) Layer
Titanium-tungsten (TiW) Layer
Copper (Cu) Seed Layer
Copper Layer Copper Layer Copper LayerCopper Layer
Tin (Sn) Layer Tin (Sn) LayerTin (Sn) Layer Tin (Sn) Layer
PR PR
Sputter, or Plating
of Barrier/Seed
Layers Al/TiW/Cu
Electrolytic Plating
Layer
Semiconductor Copper Electroplating Process
N+ = Phosphorus PH3 (phosphine gas) = rich in electrons (-)
P+ = Boron B2H6 (diborane gas) = rich in holes (+)

83. 83
Photovoltaic Power Equations (all solar cells)
Efficiency η, “Eta“ - A solar cell's energy conversion efficiency is the percentage of power
converted (from absorbed light to electrical energy) and collected, when a solar cell is connected
to an electrical circuit. This term is calculated using the ratio of the maximum power point, PM,
divided by the input light irradiance (E, in W/m2) under standard test conditions (STC) and the
surface area of the solar cell (AC in m2).(Higher is betterHigher is better)
Fill factor (FF) - Another defining term in the overall behavior of a solar cell is the fill factor (FF).
This is the ratio of the maximum power point divided by the open circuit voltage (Voc) and the
short circuit current (Isc). The fill factor is directly affected by the values of the cells series and
shunt resistance. Increasing the shunt resistance (Rsh) and decreasing the series resistance (Rs)
will lead to higher fill factor, thus resulting in greater efficiency, and pushing the cells output power
closer towards its theoretical maximum. (Higher is better)Higher is better)
JSC = Short Circuit current density
PM = Peak Power –Pmax
VOC = Voltage Open Circuit
ISC = Current Short Circuit
RS = Resistance Series
I = Output current (amperes)
IL = Photo-generated current (amperes)
ID = Diode current (amperes)
ISH = Shunt current (amperes)
RSH = Shunt resistance
I = IL − ID − ISH

84. 84
How the manufacturing process affects the parameters
1. Saw damage removal (wet etch)
2. Texturization (wet etch)
3. Anti-reflective coating (ARC) (sputtering)
4. Emitter formation (thermal diffusion)
5. Edge isolation (laser etch)
6. Back surface formation (screen printing)
7. Front contact formation (screen printing)
8. Contact firing (furnace)
Voc Isc Fill Factor
Metallization
Focus on
step 6, 7, 8
Edge Isolation can also be done after step 8

85. 85
Solar Cell parameters (Voc, Isc, FF, Efficiency, Rs, Rsh)
 Voc (Higher is best) – Open Circuit Voltage : determined by purity of the cell,
surface passivation (SiNx passivation and Al-BSF passivation)
 Isc (Higher is best) – Short Circuit Current : determined by purity of the cell,
amount of sunlight in, conversion efficiency of the cell (fewer recombination of
electrons is best)
 FF (Higher is best) - Fill Factor: Determined by shunt resistance Rsh (Higher is
best) and series resistance Rs (Lower is best).
 Efficiency (Higher is best) : Determined by Voc, Isc and FF
Crystalline silicon devices are now approaching the theoretical limiting efficiency of 29%.

86. 86
How to look at the data
Comparing data:
FF, Voc, Isc, Efficiency, Rsh: Higher is better
Rs, Rc: Lower is better
Voc: Al-BSF material and processing
Isc, FF: Ag FS and processing
FF affected by Rs and Rsh
Efficiency affected by Voc, Isc and FF

87. 87
Factors for Voc
 Impurities in the solar cell are on the surface and inside
the wafer
 Surface passivation is the process by which impurities on
the surface are reduced so charge ‘lives’ longer
 Saw damage and texturing create such impurities.
Passivated by SiN coating (front) and Al-BSF paste (back)

88. 88
Rshunt (Rsh)
Shunt Resistance (Rsh): A low-resistance connection between two points in an
electric circuit that forms an alternative path for a portion of the current. High
Rsh is best. Low shunt resistance causes power losses in solar cells by
providing an alternate current path for the light-generated current. Such a
diversion reduces the amount of current flowing through the solar cell junction
and reduces the voltage from the solar cell. Shunts can be created during
processing by residues of the emitter at the cell edge, by material induced, and
by scratches. Shunts can also occur below grid lines due to the metallization.
Shunts due to the metallization - Front metallization shunts become difficult to avoid
when low contact resistance (Rc) values need to be achieved.
Shunts due to scratches - handling issue
Material induced shunts - material contamination induced during crystal growth
Edge shunts - poor edge isolation

89. 89
Rseries, Rcontact and Isc - Front grid tradeoffs
Emitter
Base resistance (Re)
Lateral Emitter resistance (RL)
Gridline/Emitter contact resistance (RC)
Gridline resistance (RG)
RSeries = RG + RC + RL + RE
Need to maximize Fill Factor (FF) by
reducing RG, RC from gridline (RL, Re
determined by wafer)
Contact resistance (Rc) > 50% of resistance
in best cells, largest impact on overall
resistance. Contact resistance is highly
specific to firing conditions
Need to maximize Isc by
reducing lines and linewidth

90. 90
Key questions we need to know from customers
 What is your Voc/Isc/Efficiency/FF baseline in production?
(What are future targets?)
 What is your emitter sheet resistance?
 What line width (Critical Dimension CD), aspect ratio are you
targeting?
 We have shown that efficiency can be increased with Al-BSF in
a DoE to optimize process conditions in our presentation, can we
start with an Al-BSF evaluation with your company?
 Our backside Ag Tabbing paste is formulated to perform best
with our Al-BSF, can we send a sample of our Ag Tabbing with
the Al-BSF
With these 5 questions to the customers we can have high chance
of succeed in an evaluation.
Front
side Ag
Back side
Al-BSF
and Ag
Tabbing

91. 91
Let’s analyze the Evergreen Solar DoE data together
Split Al Dry Firing N Eff Voc Isc FF Rs Rsh RBB RDD
5 Toyo 200/220 875/865 495 15.12% 0.6031 3.945 76.70 0.0068 208 0.039 0.0091
1 Dongjin-1 200/220 875/865 508 15.20% 0.6057 3.953 76.61 0.0068 129 0.034 0.0135
3 2 Sun-3 200/220 875/865 497 15.14% 0.6051 3.928 76.88 0.0062 163 0.034 0.0102
3 2 Sun-4 200/220 890/880 506 15.14% 0.6053 3.926 76.88 0.0063 166 0.033 0.0101
7 5 Sun-5 200/220 905/895 512 14.96% 0.6049 3.914 76.22 0.0076 161 0.033 0.0107
4 3 Sun-6 160/180 875/865 512 15.13% 0.6053 3.924 76.87 0.0061 176 0.034 0.0102
2 1 Sun-7 160/180 475/525/625/650/855/865 513 15.15% 0.6049 3.925 76.99 0.0060 157 0.033 0.0104
6 4 Sun-8 160/180 475/525/625/650/870/880 505 15.11% 0.6052 3.914 76.94 0.0062 157 0.033 0.0104
5 Dongjin-2 180/200 475/525/625/650/870/880 470 15.12% 0.6051 3.940 76.51 0.0069 97 0.032 0.0142
Comparing Dongjin-1 and Sun-7: Efficiency delta is .05% is mainly due to both lower Voc and Isc. However Voc delta is only .8 mV or .0008 V so efficiency is mainly affected by Isc with
Sun-7 is lower than Dongjin-1. With this data we are very competitive as a lead free to a leaded material. This become a price, logistic, support play and focus on leaded material has
larger Cost of Ownership due to waste disposal of paste and process

92. 92
Good Installation Practices – Wire Management

93. 93
Good Installation Practices – Support Structure and Attachment

94. 94
Good Installation Practices – Nice Work

95. 95
Good Installation Practices – Nice Work

96. 96
Good Installation Practices – Nice Work

97. 97
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
Inverters take care of four basic tasks of power conditioning:
• Inverters are the brains and the point of connection to the loads
• Converting the DC power coming from the PV modules or battery bank to AC power
• Ensuring that the frequency of the AC cycles is 60 cycles per second
• Reducing voltage fluctuations
• Ensuring that the shape of the AC wave is appropriate for the application, i.e. a pure sine wave for
grid-connected systems (Vary in quality – Square Wave, Mod-Square Wave, Sine Wave)
Criteria for Selecting a Grid-Connected Inverter – The following factors should be considered
for a grid-connected inverter:
• A UL1741 listing of the inverter for use in a grid-interactive application
• The voltage of the incoming DC current from the solar array or battery bank.
• The DC power window of the PV array. Maximum DC input current as regulated by the inverter
• Characteristics indicating the quality of the inverter, such as high efficiency and good frequency and
voltage regulation
• Additional inverter features such as meters, indicator lights, and integral safety disconnects
• Manufacturer warranty, which is typically 10 years (for rebate at least 10 years)
• Maximum Power Point Tracking (MPPT) capability, which maximizes power output
• Maximum continuous output power at 40 degree C
• Max AC Output Current - Maximum rate of electricity flow, in amperes, that the inverter can export

98. 98
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
Waveform Types
Alternating current (AC) signals are described in terms of their waveform
• Square Wave: Only appropriate for small resistive heating loads, some small appliances &
incandescent light
• Modified Square Wave or Quasi-Sine Wave or Modified Sine Wave: Appropriate for wide range of
loads including motors, lights, and standard electronic equipment
• Sine Wave: Best for sensitive electronic devices as they provide the highest quality waveform
AC Waveforms

99. 99
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
Key Specifications for Grid-Tied Inverter:
• Waveform Type
• Peak Efficiency
• Voltage Input
•Operating Range
•MPPT Range
•Maximum
•Minimum to Turn-on
• Current Input
•Operating Range
•Maximum
• Output Voltage 120/240 VAC and Output Frequency 50Hz/60Hz
• Output Continous Power - AC Total Connected Watts
• Surge Capacity

100. 100
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
Maximum Power Point Tracking: Voltage Range
Definition: The voltage window within which an inverter can maximize array output power by finding
the knee of the array’s I-V curve
•Keep the maximum power point (MPP) of an array within the inverter’s MPPT window through a
wide variety of operating conditions
•Ambient temperature has the most direct correlation to PV output voltage. Calculate the
expected operating voltage at the average high temperature for the site
•The expected array MPP voltage needs to be comfortably within the inverter’s MPPT range
•An additional voltage cushion for the effects of module power tolerance, degradation and high
temperature conditions
Maximum Input Current
Definition: The maximum DC input current as regulated by the inverter
•Designers should use array short circuit current for all NEC calculations on the DC side of the
system, not the maximum inverter input current
•One place that designers will use the maximum inverter input current is for voltage drop
calculations

101. 101
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
Number of String Inputs
Definition: The total pairs of PV positive and PV negative input terminal plugs provide by the
manufacturer
•The number of input strings determines the maximum number of PV source circuits that can be
landed in the inverter without paralleling any strings externally
•Typical as the inverter capacity increases, so does the number of terminals provided inside the
inverter. But it is often convenient and sometimes necessary to parallel strings in the field before
pulling conductors to the inverter. Fused combiner boxes are typically used for this purpose.
•Keep in mind that PV systems with more than two paralleled strings per inverter may require
series string fusing.
Number of Independent MPPT Circuits
Definition: Total number of independent MPP tracking input circuits supported by a given inverter’s
design.
•Most currently available inverters offer a single MPPT circuit and require identical string input
characteristics
•Unless an inverter with multiple MPPT circuits is specified, array strings with dissimilar numbers
or models of PVs or different string orientations should feed multiple inverters to maximize
energy harvest

102. 102
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
CEC Rated Maximum Continuous Output Power
Definition: The maximum continuous output power at 40 degree C as reported on the CEC inverter
performance test summary.
•Rated continuous output power is one of the inverter characteristics published in the test reports
for the CEC and published on manufacturer’s cut sheets.
•Designers will consider an inverter’s rated output power when determining the maximum or ideal
array size for their application.
Maximum AC Output Current
Definition: The maximum rate of electricity flow, in amperes, that the inverter can export to the utility
grid.
•Maximum AC Output Current is used for sizing wiring and the minimum overcurrent protection
device (OCPD) rating on the inverter output.
•Per NEC Article 690.64(B) PV system currents are considered continuous
•For design purposes, this means that the minimum OCPD rating for inverter output circuits is
125% of the maximum output current. Be sure to upsize the AC OCPD to a standard size
breaker for use, without exceeding the maximum OCPD rating for the inverter.

103. 103
Balance of PV Systems (BOS) – Inverter (On-Grid, Grid-Tied)
Total Harmonic Distortion
Definition: The percentage (%) of the total current in a circuit that is at frequencies higher than the
fundamental waveform frequency. THD describes the power quality entering the utility grid from an
interconnected inverter.
•The IEEE is the entity responsible for defining the power quality standards for gridtied inverters.
•Because grid-synchronous inverters meet or exceed the power quality for the utility grid, system
designers rarely need to consider THD. In rare cases, inverter THD may cause interference with
other loads, such as interference with a power line communication carrier signal for a
sophisticated lighting control system.
Peak Efficiency
Definition: The maximum percentage (%) of DC input power inverted to AC output power as measured
in bench tests and reported by the manufacturer
•Every inverter is tested at a range of input voltages and power levels. The results of these tests
are often summarized as a single efficiency curve that is published on an inverter cut sheet
•Peak inverter efficiency defines an isolated data point on a very dynamic scale and is primarily a
marketing point for manufacturers with minimal design implications.
•Pay attention to the power input range with the highest overall efficiency or to the different
efficiency curves resulting from different input voltages. This information is included in the CEC
inverter performance test summaries.

104. 104
Balance of PV Systems (BOS) - Inverter
Stand Alone (off-grid) Inverters:
• Vary in quality – Square Wave, Mod-Square Wave, Sine Wave
• Make their own AC signal output – Do not need the utility
• Must be connected to batteries
• Are less expensive than utility interactive
• A UL1741 listing of the inverter for use in a grid-interactive application
• The voltage of the incoming DC current from the solar array or battery bank.
• The DC power window of the PV array. Maximum DC input current as regulated by the inverter
• Characteristics indicating the quality of the inverter, such as high efficiency and good frequency and
voltage regulation
• Additional inverter features such as meters, indicator lights, and integral safety disconnects
• Manufacturer warranty, which is typically 10 years (for rebate at least 10 years)
• Maximum Power Point Tracking (MPPT) capability, which maximizes power output
• Maximum continuous output power at 40 degree C
• Max AC Output Current - Maximum rate of electricity flow, in amperes, that the inverter can export

105. 105
Photovoltaic Performance Parameters
V(voltage) = I(Current) x R(Resistance) = Volts (V symbol)
I = V / R = Ohms (Omega symbol)
R = V / I = Ampere (A symbol)
Power (P) (watt) = I x V
Energy (kWh) = P x Time
Pmp = Imp x Vmp
Standard Test Conditions: (STC):
1000 W/m2 solar irradiance, 25
degree C PV cell/module
temperature, 1.5 Air Mass (solar
noon)
f = Empirical DC to AC factor = 0.77
for Grid Connected (GC)
f = 0.66 for Off-Grid / GC w/batteries

106. 106
Current varies with Irradiance
Siemens SP75 Solar Module – Performance at Different Irradiances
Sunlight increase = Current increase

107. 107
Impact of Temperature on a Solar Cell
Siemens SP75 Solar Module – Performance at Different Cell Temperatures
Different PV module technologies will have different temperature coefficients
As a rule of thumb: - 0.5% / degree C (Temp. Increase = Voltage Decrease)

108. 108
Irradiance and Irradiation
Solar Irradiance = Solar power per unit area = W/m2 or
kW/m2
Solar Irradiation = the total irradiance over time
Irradiation = a measurement of Energy in sunlight = Watt-
hours/m2 or kWh/m2
Peak Sun Hours = an equivalent
measure of total solar irradiation in a
day where irradiance varies throughout
the day
Reference (Good Book): Photovoltaic Systems (2nd
Edition) by James P. Dunlop
Maximum Power
Point Tracking –
Current decrease as
Irradiance falls in the
afternoon thus change
Maximum Power

109. 109
Power and Energy Compared
Power Energy
Instantaneous measurement – a RATE Metered over a period of time – a COUNT
In Electrical terms:
Measured in
Watts (W)
Kilowatt (kW)
In Electrical terms:
Measured in
Watt-hours (Wh)
Kilowatt-hours (kWh)
Calculations:
Power = V x I
P (watts) = Voltage x Current
Calculations:
Energy = Power (watts) x Time (hours)
Energy = P x Time (h)
Irradiance:
Watts per Square Meter = W/m2 or kW/m2
Irradiation:
Watt-hours/m2 or kWh/m2
Peak Sun:
1000 W/m2 = Peak Sun = 1 kW/m2
Peak Sun Hour:
1000 watt-hours/m2 = 1 kWh/m2 = 1 Peak Sun Hour
PV System Energy per Day in kWhs = [(Watts DC STC) x (f) x (SH) = watts in AC
where:
STC = PV Array rating in Watts DC STC
f = de-rating factor (DC to AC) ~ 77%
SH = Sun-Hours per day given the PV array tilt = Watts/m2 measure with the irradiance
meter aimed at the sun with the same tilt as the array tilt
Multiply result by days in month = ~ monthly performance
Multiply result by 365 days = ~ annual performance

110. 110
USA Average Daily Solar Radiation Per Month by NREL

111. 111
Sun Path Chart for 30 degree North – Austin, TX

112. 112
NREL - PV Watts Calculation data
NREL PV – Watts : A performance Calculator for Grid-Connected PV Systems
http://rredc.nrel.gov/solar/calculators/pvwatts/version1/

113. 113
Required Information for Permit – Site Plan
Site plan showing location of major components on the property. This drawing need not be
exactly to scale, but it should represent relative location of components at site.

114. 114
Required Information for Permit – Electrical Diagram
Electrical diagram showing PV array configuration, wiring system, overcurrent protection,
inverter, disconnects, required signs, and ac connection to building.

115. 115
Required Information for Permit – Specifications Sheets, Install Manuals, One-Line Diagram
Specification sheets and installation manuals (if available) for all manufactured
components including, but not limited to, PV modules, inverter(s), combiner box, disconnects,
and mounting system.
One-Line Diagram should have sufficient detail to call out the electrical components, wire
types/sizes, number of conductors, and conduit type/size where needed.

116. 116
Codes / Standards / Permits / Guidelines
 Objectives of the Guidelines are to facilitate the installation of safe
systems at a minimum of cost. Provide guidance on what information
should be provided for permitting. Discourage “fly-by-nights” from the
industry by making them do all the steps that a good installer does.
Raise the professionalism of installing contractors.
 Originally based on the 2002 National Electrical Code (NEC), Article
690, and various guidelines from a few jurisdictions and using input
from several experienced professionals including installers and
inspectors throughout the U.S. It has since been updated in 2008 for
the 2005 NEC.
 Approach is to establish a set of best practices that will help ensure
that the public safety is preserved when an installation meets these
guidelines.

117. 117
Applicable Codes and Standards for PV Systems
 National Electrical Codes – (NEC) Article 690 - Solar Photovoltaic Systems –
NFPA 70
 UL Standard:
 1703 - Flat-plate Photovoltaic Modules and Panels
 1741 - Standard for Inverters, Converters, Controllers and Interconnection
System Equipment for Use With Distributed Energy Resources
 IEEE 1547 - Standard for Interconnecting Distributed Resources w/ Electric Power
Systems
 Building Codes – ICC, ASCE 7-05
 Uniform Solar Energy Code – ICC
Electrical Equipment Listing – Recognized testing laboratories include:
1. UL
2. ETL Semko (Intertek)
3. CSA
4. TUV

118. 118
National Electrical Code (NEC) Sections Applicable to PV Systems
• Article 110: Requirements for Electrical Installations
• Chapter 2: Wiring and Protection (Most of the Chapter)
Article 250: Grounding
• Chapter 3: Wiring Methods and Materials (Most of the Chapter)
Article 300: Wiring Methods
Article 310: Conductors for General Wiring
• Article 480: Storage Batteries
• Article 690: Solar Photovoltaic Systems
• I. General (definitions, installation)
• II. Circuit Requirements (sizing, protection)
• III. Disconnect Means (switches, breakers)
• IV. Wiring methods (connectors)
• V. Grounding (array, equipment)
• VI. Markings (ratings, polarity, identification)
• VII. Connection to Other Sources
• VIII. Storage batteries
• IX. Systems over 600 Volts

119. 119
PV Incentive Programs – Varies from each local Utility Providers
 Federal Tax Incentive – 30%
 Local Utility Solar Performance-Based Incentive Program (PBI) – (usually limited to
200kW AC @ STC, derate factor of 77%)
 Commercial PV PBI program Procedures, Qualifications and Guidelines.
 Local Utility Feed-in-Tariff (FIT) – (usually 1kW to 20 kW PV system) is a policy
mechanism designed to accelerate investment in renewable energy technologies. It
achieves this by offering long-term contracts to renewable energy producers, typically based
on the cost of generation of each technology. Technologies such as wind power, for
instance, are awarded a lower per-kWh price, while technologies such as solar PV and tidal
power are offered a higher price, reflecting higher costs. In addition, feed-in tariffs often
include "tariff degression", a mechanism according to which the price (or tariff) ratchets
down over time. FIT varies from each Utility Providers.
 Local Utility Rebate – (usually 1kW to 20 kW PV system) = [Number of PV modules] x
[STC Rating/module (Watts)] x [CEC rated Inverter Efficiency] x [Rebate Level (this varies
from each Utility Providers)]
 Home Energy Efficiency Requirements
 Home Water Heating System Requirements
 Residential Solar PV Rebate Program Procedures, Qualifications and Guidelines

120. 120
Wholesales cost of Solar System
Residential Retail per Watt installed = $3.15 per Watt
Commercial Retail per Watt installed = $ 2.45 per Watt
Wholesale cost for a solar system installed
Items Cost per Watt
DC Solar Panels $ 0.80
AC Solar Panels w/ Micro-inverter $ 1.40
DC-AC Inverter $ 0.32
Racking $ 0.28
Balance of System (BOC) $ 0.25
Labor (installation crew) $ 0.22
Electrical Panel $ 1500.00 per piece (only if mandatory)
Master Electrician $ 500.00 per job
Permits / Documentation $ 400.00 per job
Rebates / Documentation $ 0.10
Solar Calculation / Invoicing $ 0.10
Financing Cost 2-7 % of loan amount (not cash sale)
Sales Commission $ 0.20 (inside sales people)
Mormons sales commission $ 0.35 (Mormons sales)
Net Profit = $ 0.73 / Watt