SOLAR CELLS ESW Sustainable Technology of the Month! Presented by: Brad Gething.

SOLAR CELLSSOLAR CELLS

ESW ESW SustainableSustainable

Technology of the Month!Technology of the Month!

Presented by: Brad GethingPresented by: Brad Gething

DISCLAIMERDISCLAIMER

I am not an expert in photovoltaics I am not an expert in photovoltaics

This presentation is not a comprehensive This presentation is not a comprehensive review of the state of the art.review of the state of the art.

Not all of the information presented Not all of the information presented originates from peer reviewed sources. originates from peer reviewed sources.

BACKGROUNDBACKGROUND1839 - 1839 - Photovoltaic effect was discovered by the French physicist Alexandre Photovoltaic effect was discovered by the French physicist Alexandre Edmond Becquerel.Edmond Becquerel.1918 - 1918 - Polish scientist Jan Czochralski discovered a method for Polish scientist Jan Czochralski discovered a method for monocrystalline silicon production. The first silicon monocrystalline solar monocrystalline silicon production. The first silicon monocrystalline solar cell was constructed in cell was constructed in 19411941. . 1955 - 1955 - Western Electric put for sale commercial licenses for solar cells Western Electric put for sale commercial licenses for solar cells production (mainly for space exploration). Hoffman Electronics-production (mainly for space exploration). Hoffman Electronics-Semiconductor Division introduced a commercial photovoltaic product with 2 Semiconductor Division introduced a commercial photovoltaic product with 2 % efficiency for $25 per cell with 14 mW peak power. Cost - $1,785 per W. % efficiency for $25 per cell with 14 mW peak power. Cost - $1,785 per W. 1973 –1973 – U. Delaware produced a photovoltaic-thermal hybrid system Solar U. Delaware produced a photovoltaic-thermal hybrid system Solar one, one of the first photovoltaic systems for domestic application. Cost - one, one of the first photovoltaic systems for domestic application. Cost - $30 per W $30 per W 1984 -1984 - 1 MW photovoltaic power plant began to operate in Sacramento, 1 MW photovoltaic power plant began to operate in Sacramento, California. ARCO Solar introduced the first amorphous modules. California. ARCO Solar introduced the first amorphous modules. 1992 - 1992 - A silicon solar cell with 20 % efficiency was patented. A silicon solar cell with 20 % efficiency was patented. 2002 - 2002 - Cumulative worldwide installed PV capacity expected to reach 2000 Cumulative worldwide installed PV capacity expected to reach 2000 MW MW

AVERAGE SOLAR IRRADIANCEAVERAGE SOLAR IRRADIANCE 1991-1993 1991-1993

W/mW/m22

World Energy DemandWorld Energy Demand

GW-hrGW-hr

20032003 2030 (est.)2030 (est.)

1.2331.233EE88 2.1162.116EE88

US Energy DemandUS Energy Demand

GW-hrGW-hr

20032003 2030 (est.)2030 (est.)

2.9372.937EE77 3.8443.844EE77

CONTEXTCONTEXT

CONTEXTCONTEXTLocation, Location, DesertDesert

Desert Size Desert Size

kmkm22

Irradiation Irradiation

W/mW/m22

Area Area Required Required

kmkm22

Energy Energy OutputOutput

GW-hrGW-hr

Africa, Sahara Africa, Sahara 9,064,960 9,064,960 260 260 144,231144,231 2.0552.055EE77

Australia, Great Australia, Great Sandy Sandy

388,500 388,500 265 265 141,509141,509

China, China,

Takla Makan Takla Makan

271,950 271,950 210 210 178,571178,571

Middle-East, Middle-East, Arabian Arabian

2,589,910 2,589,910 270 270 138,889138,889

South America, South America, Atacama Atacama

139,860 139,860 275 275 136,364136,364

U.S.A.,U.S.A.,

Great Basin Great Basin

492,100 492,100 220 220 170,455170,455

HOW THEY WORKHOW THEY WORK

11

Si-P

Si-B

33Si-P

Si-B

22

Si-P

Si-B

ECONOMICSECONOMICS

A 3 kW PV residential retrofit system in the US A 3 kW PV residential retrofit system in the US costs ~$25,000costs ~$25,000Amortized over a 20 year mortgage, the cost of Amortized over a 20 year mortgage, the cost of PV electricity is ~25 cents per kWh in most U.S. PV electricity is ~25 cents per kWh in most U.S. locationslocationsThe average cost of utility/grid electricity is 8.2 The average cost of utility/grid electricity is 8.2 cents per kWh in the U.S. and between 0.10 and cents per kWh in the U.S. and between 0.10 and 0.15 €per kWh in Europe.0.15 €per kWh in Europe.Studies suggest an added hidden societal cost Studies suggest an added hidden societal cost behind all fossil-fueled power plant ranging from behind all fossil-fueled power plant ranging from 7 to 20 cents per kWh.7 to 20 cents per kWh.

ECONOMICSECONOMICS

Although the production of electrical grade Although the production of electrical grade Si has increased, acquisition of raw Si has Si has increased, acquisition of raw Si has not.not.

DEMAND > SUPPLYDEMAND > SUPPLY

ECONOMICSECONOMICS

KEY POINT KEY POINT

Costs can be reduced by:Costs can be reduced by: Alternative materialsAlternative materials

Reduced material costReduced material cost

Reduced processing costReduced processing cost

Increased efficienciesIncreased efficiencies Alternative uses of SiAlternative uses of Si

Amorphous Si (non-crystalline)Amorphous Si (non-crystalline)

Si layered with glassSi layered with glass

ALTERNATIVESALTERNATIVES

MaterialsMaterials Cadmium TellurideCadmium Telluride PolymersPolymers Dye-sensitized solar cellsDye-sensitized solar cells

ProcessingProcessing Thin filmsThin films Ribbon PrintingRibbon Printing Nano-crystalline materialsNano-crystalline materials

EFFICIENCIESEFFICIENCIES

Amorphous silicon (Tandem)Amorphous silicon (Tandem) 6 - 7% 6 - 7%

Cadmium Telluride (CdTe) thin filmCadmium Telluride (CdTe) thin film 8 - 10% 8 - 10%

Multi (or Poly) crystalline siliconMulti (or Poly) crystalline silicon 12 -15%12 -15%

Mono-crystalline silicon (SiN)Mono-crystalline silicon (SiN) 13 -16%13 -16%

Saturn Mono-crystalline siliconSaturn Mono-crystalline silicon 15 -18%15 -18%

WANT TO LEARN MORE?WANT TO LEARN MORE?

PSU CoursesPSU Courses EDSGN 497A: Sustainable Design and EngineeringEDSGN 497A: Sustainable Design and Engineering ENGR 097S: Solar RacersENGR 097S: Solar Racers

Center for Sustainability (www.engr.psu.edu/cfs)Center for Sustainability (www.engr.psu.edu/cfs) Solar DecathlonSolar Decathlon

www.solar.psu.eduwww.solar.psu.edu Powerlion- portable PV stationPowerlion- portable PV station New 1750 W PV arrayNew 1750 W PV array

Penn State Energy Institute – Sustainable Energy Penn State Energy Institute – Sustainable Energy ResearchResearchFacultyFaculty

Dr. Andy Lau – ASE Dr. Andy Lau – ASE Dr. Christopher Wronski – EEDr. Christopher Wronski – EE Dr. John Asbury - ChemistryDr. John Asbury - Chemistry

REFERENCESREFERENCES

http://www.pvresources.com/en/history.phphttp://www.pvresources.com/en/history.phphttp://en.wikipedia.org/wiki/Photovoltaicshttp://science.howstuffworks.com/solar-cell.htm““Everything You Wanted to Know About Solar Everything You Wanted to Know About Solar

PhotovoltaicsBut Were Afraid to Ask”, BP Solar PhotovoltaicsBut Were Afraid to Ask”, BP Solar PublicationPublication

International Energy Outlook 2006International Energy Outlook 2006, , Energy Information Energy Information AdministrationAdministration

Annual Energy Outlook 2007 Annual Energy Outlook 2007 , , Energy Information Energy Information AdministrationAdministration

Flin, David. “Thin films for fat profits”, Flin, David. “Thin films for fat profits”, Modern Power Modern Power SystemsSystems, 26(2), 2006. , 26(2), 2006.

LET’S CHAT!LET’S CHAT!QUESTIONS??QUESTIONS??COMMENTS??COMMENTS??

““I'd put my money on the I'd put my money on the sun and sun and solarsolar energy. energy. What a source of power! What a source of power! I hope we don't have to I hope we don't have to wait till oil and coal run wait till oil and coal run out before we tackle out before we tackle that.” that.”

--Thomas Edison--Thomas Edison

“If to do were as easy as to know what is good to do, then

paupers would be princes and a poor man’s hovel, a rich man’s

estate.”

– William Shakespeare