CChu Green Energy Workshop 2012 Website

8/13/2019 CChu Green Energy Workshop 2012 Website

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3rdAnnual IEEE Green Energy

Workshop, 2012 CSULB

Dr. Chaw-Long Chu

November, 19th, 2012


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1. Why Solar Power we need to knowCurrent Status2. Source: Solar Spectrum

3. Solar Power Application:

3A Water Heater--- a device has been used for

more than 100 years.3B Solar Cell--- In recent 40 years, systematic R/Don solar power has generated sophisticateddevices to convert light to electricity

4. Discussion

genda


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1. Global warming and extra CO2generation

2. Nuclear and coal plants are not favored, petroleum price is high,natural gas is cheap, but still generate CO2. Hydraulic, geothermalhave geography limitation, wind power has advantage on lowercost but not so dependable and suitable for residential area.

3. New emerging economic regions consume more energy (Asia,

Africa, middle East, and South America)4. Multi Government sponsored incentive programs to encourage

Solar Electricity

5. Due to production improvement, significant price reduction on

Solar module; solar electricity is cheaper than new nuclear energyplant and is approaching grid parity.

6. Global Installed Solar Module increased from 71.5 MW (1995) to30 GW (2012)

7. It is a convenient and low cost emergency relief power.

Part 1. Why Solar Power and What is the status


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Halloween, 2012 will be a horrible night for so many northeastresidentsStorm, Flood, Fire, and Power Outage.

Trick or Treat!


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Where is Electricity?!


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Hurricane Sandy Power Outage Map (11/1/2012)

Where is electricity?


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11/2/2012 Jersey City residents lined up for gas supply to operatehouse generator, it took 3 hours to wait. Where is electricity?


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New Yorkers were waiting for gas; day and night, noelectricity to operate oil pump and shut down mostgas stations. Where is electricity? (11/3/2012)


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CO2reachtipping point

Higher Seelevel

Higher Seewater

temperature

Matched byCold storm

HurricaneSandy Moved

upward

Form a PerfectStorm to attackNE USA

Flood

PowerPlantExplosion

Fire

PowerOutage

We need greenenergy to reduceCO2emission tosave the earth

KYOTO PROTOCOL TO THE UNITED NATIONS FRAMEWORK

CONVENTION ON CLIMATE CHANGE

UNITED NATIONS 1998

How about nuclear energy? Itwont generate CO2.


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San Onofre Nuclear Generating Station(~ 50 miles from CSULB)


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Diablo Canyon Nuclear Power Plant (San Louis Obispo, CA)1927, Lompco Earthquake (magnitude 7.1) was 2.5 miles

offshore from the NPP and Shoreline Fault is 1 mile from NPP


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Worldwide Solar PV Growth (GW)

30.0

On 2012, USA will install more than 2.5 GW (This is larger

than the summation from 2000 to 2010)


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Annual Value of Renewable Energy Installation(2012 and after is estimation)


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USA Annual Installed Grid-Connected PV Capacity (2002-2011)

If 1 watt charges $2.5, $4.61 billion was spent in 2011 by USA.


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Why solar power knowledge is important

Solar energy will be more popular in coming 20 years

Solar energy and related business will hire moreemployees (current employee number ~ 100,000 in USA)

Solar power will be popular in emerging economic area

More solar module will be fabricated in USA for domesticsupply (international?)

Most solar heat is used for hot water generation, itindirectly reduced the consumption of electricity andnatural gas

Solar electricity is directly used to power daily life.


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Part 2, Solar Spectrum

Solar Power is characterized by its spectrum, the intensity is

affected by the distance (solid angle) and the materialsexisting between the light source and the detecting spot;

Outside but close to the atmosphere of earth, AM0 (air mass zero) -135.3 mW/cm2, on the surface of earth (sunny) AM1.5100 mW/cm2(average). Both intensity and spectrum are affected by atmosphere and

water vapor.Photon energy at specific wavelength (i) = nic/i (ni: number ofphoton, : Planck's constant = 6.626068 10-34m2kg /s, c: lightvelocity)Direct industry application of solar energy: to warm up any media byabsorbing the solar spectrum

In-Direct industryapplication of solar energy: to produce electron byabsorbed photon (ideal case: one photon to generate one electron)


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135.3mW/cm2

100.0mW/cm2


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Solar Heater: Supply Hot WaterTo save heating energy (electricity or gas)

9 million water heaters (~USD 450/unit) sold in USA,total revenue is about 4 billion/y.

Natural Gas is cheap in USA, Canada, Russia. But, itis very expensive in Japan, most Asia area, and

Europe. Solar water heater system could also warm uphouse.


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Advertisement of Solar Water Heater (1902)


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Flat Plate Solar Water Heater forIndustrial or Commercial Areas


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Solar Heater for Residential Area


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Tube Shape Solar Water Heater


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Minimum Design Criteria of solar hot water system

1. The temperature and quantity of hot waterrequired from the system.

2. Changes in ambient temperature and solarradiation between summer/winter and day/night.

3. The possibility of the potable water or collector

fluid overheating or freezing.4. Potential application: house warming5. Other requirements have to be satisfied:

1. Building code it may vary from city to city,2. Geographic limitation


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Classification of solar hot water systems


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Classification of solar hot water systems

Direct system: Use solar heat to warm the water, noprotection design

Indirectsystem: Use Heat Transfer fluid to transferthe solar heat to water, overheat and anti-freezing

protection is provided (cost higher) Passive system: Use the heat as convection driven

force to circulate the water and heating fluid (for bothDirect or Indirect system)

Activesystem: Use pump to circulate the water and

heating fluid (higher cost, but highest efficiency)


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1. Heating efficiency is wavelength dependent and it varies from liquid to liquid

2. The solar power could be properly shared by Solar cell and water heater.


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Engineering/Business Concerns ofSolar hot water system Design

1. Reliability of components2. Water source criteria (hard or soft

water)3. Heating rate and solar spectrum4. Average water temperature: >500C.5. Criteria for heat transfer fluid

selection6. Weight limitation for roof top

installation7. Performance survey and user

expectation8. How many major vendors to provide

the heater, globally and domestically9. How to design a house warming

system using this design

10. Discussion


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Global Installation of Solar hot water system


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Break Time


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Solar Spectrum Definition


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135.3 mW/cm2

100.0 mW/cm2

GaP

SiZnS

Ge

ZnO

GaAs

CdSe

CdTe

InP

GaSb

InAs(3.44x10-6)

InSb(7.29x10-6)


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Band Gap and Lattice Constantof II-VI, III-V, and IV-IV Compounds


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Point Focus Parabolic Dish


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Concentrated Photovoltaic Panel (CPV)

Single axis trackers with roughly 20 degree tilt at


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Single axis trackers withroughly 20 degree tilt at

Nellis Air Force Basein Nevada, USA
http://en.wikipedia.org/wiki/Nellis_Air_Force_Basehttp://en.wikipedia.org/wiki/Nellis_Air_Force_Base


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What is solar cell?


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A device to convert light to electricity Any material or material combination to convert light

or EM-wave to energized electrons (engineering part)and used for operation of motor or equivalent

machines (business part) Material selection, purification, processing

(solid, liquid, gas, vacuum.)

Low resistivity conducting system to efficiently carry

the electrons

Quantitatively defined operation

Suggestive definition of solar cell


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Classification of Solar Cell

Crystalline Solar Cell: Si, Triple Junction (GaInP/GaAs/Ge,

GaInP/GaAs/InGaAs) Thin Film Solar Cell: Amorphous Si, CIGS, CdTe

Dye Solar Cell, Organic Solar Cell (R&D only)

Concentrator Solar Cell: 500 x ~ 1000x (GaInP/GaAs/Ge)

Vacuum?


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Criteria to start PV Business

Pre-Selection Criteria (Finance, Marketing, and Technology):

Richness of material resource and cost of purification Fabrication cost, market demand, and competition Potential of solar cell/solar module quality improvement Investment and Incentive opportunities Patent Issues

( money, marketing, engineering, equipment, labor, law) PV Industry includes Solar cell (materials, fabrication and test equipment, package) Solar module (materials, fabrication and test equipment,

package) Solar cell/module environment evaluation Solar module installation, maintenance, and recycle Operation Insurance


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Solar Cell/Module Design Principle

What is customers expectation

Dependability, economy, maintenance availability

Design for successful field operation Reliability

Minimum environment contamination

Operation flexibility for both regular operation and emergencyrelief

Functional enhancement

User friendly


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Designs of Solar Cell and Solar Panel

Solar Cell Structure: p/n junction, p- and n- contacts, AR-Coating

Solar Module Structure: Solar Cell, Rear Side Supporting, Front Side

protection, Adhesive, Interconnection Design Guidance: Efficiency, Cost, Weight, Reliability (20 years field

operation)

Fabrication Concerns: Yield, Operation Cost (including contaminationcontrol)

Tooling Used for Cell Design (light intensity dependent) Cell parameters: Voc, Isc, FF, Eff

Voc determined by solar cell material (band gap), junctionpreparation, cell process determined passivation effect, metalcontact resistance and series resistance

Isc determined by Solar Cell Material (minority carrier life time),

junction preparation process, front and rear contact, passivation,AR-coating

FF (the squareness of diode IV curve), determined by solar cellmaterial (direct or indirect band gap), p/n junction preparation,contact resistance and series resistance

Eff (efficiency) = (Voc * Isc * FF)/(Cell Area * Light Intensity)


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Software used for Solar Cell Design

PC-1D, essential solar cell parameters estimation (Voc, Isc,Eff) AR-Coating layer thickness optimization (Isc) No software available to calculate FF

Equipment used for Solar Cell Testing Minority Carrier LifetimeHall Effect, EBIC (SEM) Band Gap MeasurementPhotoluminescence Sheet Resistance Measurement (Bulk material)4-point

probe, spreading resistance Doping Profile -- Back Scattering Effect, SIMS, Auger, ECV Ohm MeterResistance Measurement

Solar SimulatorVoc, Isc, FF, and EFF Quantum Efficiency (or spectral response)Isc Estimation Solar RadiometerSolar Simulator Spectrum Calibration X-Ray DiffractometerLattice size determination of Epi-layer

Designs of Solar Cell and Solar Panel


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Single Junction Solar Cell and Future

Ge solar cell to begin with: low bandgap, low efficiency,

high cost material (failed) Si solar cell is a successful example: wider bandgap (1.1

eV), higher efficiency (AM1.5, ~24.7%, 1989), low costmaterial, most popular global installation solar module(>85%). It will be the main stream product in PV industry.

Concerns on weight, efficiency, and application forspecial environments, R&D on multi-junction solar cellstarted.

To reduce the cost of solar cell/module; thin film, dye,

organic solar cells started As solar module popular; retired module recycle and

environment contamination and other supporting factors,such as house insurance, mortgage, tax will be required


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Essential Solar Cell Parameters

Independent Parameters: Voc = kt/q*ln(IL/I0+ 1) (open circuit voltage)

K: Boltzmanns constant t: absolute temperature (0K) q: electronic charge IL: light generated current (Isc) I0: diode saturation current (determined by material and

related process) Isc = QE()*ni()*= QE()*ni()*d

Derivative parameters: Curve Factor (FF) = (Vmax*Imax)/(Voc*Isc) Cell Efficiency () = (Vmax *Imax)/(Power Intensity * Cell area)

Dominating factors to Voc, Isc, FF Material characteristics (Band Gap, Indirect/Direct, crystaldefects, impurities)

Solar Cell design Materials and procedures used for process


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Silicon Solar Cell (single Junction) Spectral Response

Spectral Response of GaInP/GaAs/Ge


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Spectral Response of GaInP/GaAs/Ge

Triple Junction Solar Cell

0.0

0.2

0.4

0.6

0.8

1.0

1.2

300 600 900 1200 1500 1800

Wave length (nm)

SpectralResponse(

A/W-cm2)

Top Junction (15.88 mA/cm2)

Middle Junction (16.19 mA/cm2)

Bottom Junction (27.67 mA/cm2)


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How to Test Solar Cell

Light Source Calibration (multi-artificial light

sources used to simulate the sun light) Uniformity of illuminated area

Single solar cell test

Solar module test (LAPSS-pulse light source)

Standard Cell Preparation Balloon flight (120000 ft, AM0)

Jet flight (60000 ft,


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Schematic Drawing of Solar Cell Test Set Up

Concerns of Test:

Light Uniformity and Measurement Accuracy


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1. Steady Light Simulator

2. Large Area Pulse Solar Simulator


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GaInP/GaAs/InGaAs (MOCVD)

Block Diagram of Major Solar Cell Process


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Equipment Used for Solar Cell Fabrication

Si solar cell

Si ingot grower, Wire Dicing machine (Wire saw and Disc Saw),Junction Diffusion Machine, Si3N4 CVD, Screen Printing Machine,Annealing Tube, AM 1.5 Simulator/Testing Setup, Microscope

Thin Film Cell

Substrate Preparation (Glass, Metal Sheet, or Kapton Sheet),Sputtering or Co-Evaporation Machine, Transparent ConductingContact Sputtering Machine, Collector-Grid Screen Printer, CellInterconnector, AM 1.5 Simulator/Testing Setup

GaInP/GaAs/Ge

Ge Ingot Grower, Wire Dicing machine (Wire saw and Disc Saw),Junction Generation Machine (MOCVD), Front and Rear Metal Grid

Evaporator, AR-Coating Evaporator, Annealing Chamber, Cell DicingSaw, Solar Simulator/Testing Setup, Microscope


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GE Flexible CIGS Module


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Triple Junction Solar Cell (4cm x 8cm) Includes


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Triple Junction Solar Cell (4cm x 8cm) Includes

Monolithic Bypass Diode

Emitter: N - GaInP2

Window: N - AlInP2

Base: P - GaInP2TC BSF

P++ -TD

N++-TD

MC WindowEmitter: N- GaAsBase: P- GaAs

Nucleation / Buffer/MCBSF

Base/Substrate: P -GeP-Contact

N++-TD

P++ - TD

Emitter: N- Ge

Top Cell

Middle Cell

Bottom Cell

Top Tunnel Diode

Bottom Tunnel Diode

P- Diode

N- Diode

Jumper

N-Diode Contact

P- Cell

Contact

Integral Bypass Diode

Diode/cell Contact


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Module Cell (Lab)

Dye-sensitized Solar Cells 3

5% (INAP) 11%

Single Crystalline Silicon 22.7% (UNSW) 24.7% (UNSW, PERL)

Amorphous Silicon

(Multijunction)10.4% 13.2%

Polycrystalline Silicon 14 -18% 20.3% (FhG-ISE)

HIT Cell (-Si/c-Si) 18.4% (Sanyo) 21% (Sanyo)

Cadmium Telluride (CdTe) 810% (FirstSolar)

16.5% (NREL)

Copper Indium Gallium

Selenium (CIGS)13.0% (TSMC) 20.3% (Miasol)

InP N/A 21.9% (Spire)

AlInGaP/InGaAs/InGaAs (IMM) N/A 33.9% (Emcore)

GaInP/GaAs/Ge (~250X) N/A 40.7% (Boeing)

GaInP/GaAs/Ge (~450X) N/A 41.6% (Boeing)

Solar Cell and PV Module Efficiency (AM 1.5)

Eff t PV I d t


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Effort on PV Industry

Reduce the fabrication cost

Silicon material reduction (cost effective?) Enhance the production scale or business merge (STP, the

world largest company is facing financial problem, Schott Solarstopped the cell fabrication in USA)

More aggressive government incentive programsrequired

Multi-functional Solar module Development and ExistingModule Flexibility Improvement

Encourage BIPV design (Many German Designs couldbe considered)

What is your contribution? How to approach?


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20 Micron Thick Si Cell

Proton radiation to lift off a thin layer Sifor solar cell process (existing Si cell is500 um thick).


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What is your contribution? How to approach?

To be an engineer as you, what will beyour contribution to this promisingindustry?

New design? New Material? New businessplan?

In addition the solar car, could school and

industry support some student activities onsolar product design?


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Documents

CChu Green Energy Workshop 2012 Website