Energía Solar - Fotovoltaica

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Energía Solar - Fotovoltaica

Solar Photovoltaics:

Powering the planet NOW!

P. Karunakaran Nair, CIE-UNAM

CIE25- 09Aug 2010

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Solar photovoltaics..

national initiatives….

Nobel laureate Octavio Paz, Mex. Ambassador to India, 1962-’68, “In Light of India”

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Energía Solar - Fotovoltaica

• - Mensaje original

---• Asunto: Plática y resumen

• De: Antonio Sarmiento Galán <ansarasg@gmail.com>

• Fecha: Vie, 23 de Julio de 2010, 12:18 pm

• Para: cestrada@cie.unam.mx

• esg@cie.unam.mx

• dir@cie.unam.mx

• "P Karunakaran Nair" <pkn@cie.unam.mx>

•

---•

• Estimado Claudio, te anexo la info que me solicitó Karuna.

• Saludos, Antonio

•

• La idea del coloquio es presentar un sistema fotovoltáico con las siguientes características:

•

• 16 paneles Kyocera KC-130, de 130 W c/u y un inversor SMA de conexión a red, de 3 kW, mod. 3000 US; potencia instalada de 2.08 kW que produce en promedio 309.5 kWh al mes (10.77 kWh al día).

• Este sistema lleva casi dos años generando la corriente eléctrica de mi casa (familia de 4 miembros en promedio; dos adolescentes con fiestas).

•

• Se invita a la participación/discusión en cuanto a las ventajas de este tipo de sistemas y los avances recientes en el campo.

•

• Antonio Sarmiento Galán, Unidad Cuernavaca del Instituto de Matemáticas de la UNAM desde 1999; Instituto de Astronomía de la UNAM(1981-1999); http://www.matcuer.unam.mx/~ansar/life.html

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Energía Solar – Fotovoltaica

¿realidad?

Casa: Antonio Sarmiento

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Energía Solar –

Fotovoltaica

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Energía Solar - Fotovoltaica

M. Smoluchowski, Foton 93 (2006) 26

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Solar Photovoltaics:

Powering the planet NOW!

Fotovoltaico Solar:

Electrificando el planeta HOY!

Silicon PV technology

PV efficiency

PV & CIE-UNAM

Powering the planet.. by the

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Solar Photovoltaics:

Powering the planet NOW!

With contributions from:

M. T. Santhamma Nair

Xavier Mathew

Hailin Hu

Oscar GomezDaza

Funding:

PAPIIT-UNAM, CONACyT,

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Solar Photovoltaics…

production of

monocrystalline ingots

m.p. Si: 1414o_{C; growth rate 5 cm/hour;}

ingots 10-30 cm diameter; 1-2 m length; 250 kg!

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Solar Photovoltaics

Top 7 polysilicon manufacturers had 2009 capacity of 114,500 t, up 98% from 2008,

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Solar Photovoltaics:

production trends..

• 2009 PV manufacture – China + Taiwan 49% • Solarbuzz, July 2010 • 2009 PV: 7,500 MWp • 2009 PV: Europe installed 77%; 74% of which was imported Solarbuzz, March 2010 • 2010: Half of world’s PV

production capacity is now in China and 2/3 growth is

there.

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Solar Photovoltaic:

energy & emission pay

back

• PV modules are

warranted at 90% of rated

power for 10 years and at

80% for 25 years.

• In 1-2 years they

pay-back the energy at 14%

efficiency in sunshine

countries

• At least 89% of air

emissions associated

with electricity generation

could be prevented if

solar photovoltaics

displaces conventional

grid-electricity.

Fthenakis, Kim, Alsema, Environ. Sci. Technol., 42(2008)2168

Breeding Solar Photovoltaic

modules by the family of natural green energy

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Solar Photovoltaics:

energy

pay-back..

Yangtzi, Salween: 13, Mekong: 8, The Economist, July 10th 2010

KedaXu, ICF congress, 2002 Hugh Rudnick, Aysen, June 2008

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Energía Solar – Fotovoltaica

…..working …rain or shine…

165 cm 99

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Solar photovoltaics

...

production, cost

reduction

August 2010 price-quotes for 230-250 Wp 14.5-15.5% modules: USD 2-4

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Why Photothermal conversion is very

efficient and Photosynthesis and

Photovoltaic conversions are less so?

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Solar Photovoltaic..

why Pt efficiency is

high

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Solar Photovoltaic..

PV and PS efficiencies

are ‘low’

“America’s sensible

fuel:” Corn ethanol: 20% less GHG-EPA

Year 2000: 1%; 2008: 7% Limit: < 10% fuel mix,15%? RFS-2 (July 2010): 15 billion out of 36 billion Gallons RF for 2022 Industrial biotech business: Year 2008: US$170bn; 2020: US$680bn; bio-polyethylene! The Economist, 3 July 2010 m-2_s-1_µm

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Carbon

dioxide WaterPHOTOSYNTHESISGlucose Oxygengas

chloroplast

Solar Photovoltaic…

not alone with low

efficiency

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Solar Photovoltaics..

not alone with low

efficiency

M. Smoluchowski, Foton 93 (2006) 26

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Solar PV…

Celda solar, su funcionamiento, y

semiconductores

1. Absorción de fotones en la unión y creación de pares e-h

2. Separación de e-h a e y h por el campo eléctrico 3. Colección de e y h por los electrodos

4. Trabajo útil (iluminación, bombeo, batería)

4 1 2 3 Energía solar Energía eléctrica

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David E. Carlson talk, March 2006

Solar Photvoltaics…

why not more efficient..

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Solar photovoltaics

…

efficiency and current

limits

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175 watts of peak

electrical output and 460 watts (1,570 Btu/hour) of thermal output

160 watts and the solar thermal output is 610 watts (2,080 Btu/hour): 80% of PT

Solimpeks Volther PowerVolt collector

Solar Photovoltaics…

PVPT..volt-therm

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Solar Photovoltaics…

high efficiency

cells

Andreas Bett, Frank Dimroth, Fraunhofer Inst. ISE, 41.1% effficiency in 20-layer GaInP-GaInAs-Ge cell, Joseph von Fraunhofer Prize, June 2010

Kinsey, Edmondson,

Amonix/Spectrolab, Prog. Photovolt. 17(2009) 279

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Solar Photovoltaics…

higher efficiency by

carrier multiplication in semiconductor nanocrystals?

(G.Nair, 2009)

Figure credit: S. Geyer & group website

-Tunable optical properties -Bright, stable, emission -Scalable synthesis

-Soluble & functionalizable

1.9-1.7 eV 3.2-2.3

eV

2 eV

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Limitations of conventional solar

cells

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Energy harvesting by CM

If CM is strong…

Reduce waste to heat.

Narrow gap semiconductors become feasible PV materials.

Possibility of exploiting two-electron chemical processes

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Solar photovoltaics…

CM & high J

_sc

from V.I.Klimov Appl. Phys. Lett. 89,123112 (2006)

Very strong enhancement

energy threshold of ~2.5-3Eg up to 7 e-h pairs from 1 photon

CM is fast

occurs in < 100 fs

Universal

Similar effects in PbSe and CdSe NCs despite 5x

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Solar Photovoltaics…

no beneficial CM in

semiconductor nanocrystals (G.Nair.., 2009)

PbX Initially large CM observed by two groups independently.

Studies showing moderate/small CM

InAs CM by non-resonant time-resolved THz. CM by interband TA

Recent interband TA: no CM observed THz study retracted

Si non resonant intraband TA CdSe TA and tPL evidence

Our work: no CM observed.

Schaller and Klimov PRL 92, 186601 (2004) Ellingson et al. Nano Lett. 5, 865 (2005)

Pijpers et al. JPC C 111, 4146 (2007)

Beard et al. Nano Lett. 7, 2506 (2007)

Schaller et al. JPC B 110, 25332 (2006) Nair and Bawendi PRB, 76, 081304 (2007)

Schaller et al. Nano Lett. 7, 3469 (2007) Ben-Lulu et al. Nano Lett. ASAP (2008) Pijpers et al. JPC C 112, 4783 (2008) Nair et al. PRB, 78, 125325 (2008) Trinh et al. Nano Lett. 8, 1713 (2008)

McGuire et al. Acc. Chem. Res. 14, 1810 (2008) Ji et al. Nano Lett. 9, 1217 (2009)

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Solar photovoltaics…

IIM/DES/LES/CIE

1979..

• Thin film photovoltaics

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CIGS flexible PV CuInGaSe2/CdS/ZnO www.cigssolar.com DSSC scheme: M. R. Jones

27 May 2009, Wikipedia S. Babar, Wikipedia 28 Feb ‘10

Celdas solares: posibilidades

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Solar Cells based on CdTe

• Low carrier

concentration

• Ohmic contacts

• Mis-match between

CdTe and CdS

• Absorption losses in

CdS

• Binary compound

• Easy and scalable

processing

• Nearly optimum

band gap

• Very stable

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Actual scenario

• Record

efficiency-16.5% (NREL)

• Commercially

proven technology

$1/Watt Feb. 2009

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CdTe photovoltaics program at

CIE-UNAM

CSS system Thin Films by CSS

CdS, 2-5 min. CdTe, 4 min. Thermal treatments, 5 min.

Fast process, economical in terms of investment/product ratio, and easily adaptable in a production line.

Back contact

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CdTe based wide band gap alloys for

applications in Tandem devices

Cd

_1-x

Mg

_x

Te

Eg= 1.5 to 3.5 eV; (x= 0 to 1)

CdTe

CIS

Four -terminal tandem cell based on CdTe and CIS absorbers

CdTe

CIS

Four -terminal tandem cell based on CdTe and CIS absorbers

Top-cell CdMgTe

/CdS

Efficiency of the Cd

_1-x

Mg

_x

/CdS top-cell

developed at CIE = 9.3%

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Band gap vs. x

E

_g

(x) = 1.5 + 0.3x (1-x) + 2x

E

_g

(eV)

x

1.47

0

1.51

0.02

1.61

0.08

1.7

0.13

1.74

0.15

2.11

0.35

(Hartmann et al, J. Appl. Phys. 80 (1996) 6257)

X. Mathew, J. Drayton, V. Parikh, A.D. Compaan

Proceedings of the IEEE 4th World Conference on Photovoltaic Energy Conversion (IEEE Cat. No. 06CH37747). IEEE. 2006, pp. 6. Piscataway, NJ, USA.

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Active projects at CIE

-Scale up to 100 cm

2

_{area modules}

-Pilot plant for the in-line production

of CdTe/CdS modules.

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•Celdas Solares Híbridas preparadas en el CIE-UNAM

Metal P3OT CdS ITO, ITO, Ag,Cu Ag,Cu CdS CdS 4.6-4.7 3.5 Ec Ec Ev Ev LUMO LUMO HOMO HOMO 1.9 2.4 4.5 4.2 Al Al 5.3 Au Au P3OT P3OT Ni,Au 5.1-5.3 Unit: eV Vacuum level: 0 e -h+ e -h+ Photocurrent Transparent conductor

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Chemical bath deposition of CdS (Nair et al.): Cd(NO₃)₂ 0.1 M 25 ml Citrato de Sodio 1 M 15 ml NH₄OH 15 M 2 ml Tiourea 1 M 5 ml Agua Destilada 53 ml Total 100 ml At 60 o_{C for 3 horas}

=> Thin films of !200 nm thick.

ITO/glass.

60-80°C

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S

+ sal de fierro

•1.8 g (0.0111 mol) FeCl₃en 100 ml CHCl₃.

•2.45 g (0.0125 mol) destilado y frío de 3-octiltiofeno (o 3-hexiltiofeno) en 30 ml CHCl₃.

•Agitar la mezcla por 24 h.

•Poner la mezcla en 500 ml de metanol. •Filtrar la mezcla.

•Lavar el precipitado con metanol, HCl (10%), agua destilada y acetona. •Secar el producto (polvo negro).

•Disolver el producto en toluene o CHCl₃.