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EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
EcoOne - SolarEnergy Presentation 2014
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EcoOne - SolarEnergy Presentation 2014

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Solar Energy by EcoOne Homes

Solar Energy by EcoOne Homes

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  • 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

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