Solar Energy

Bruce Logue and Robert Chou

The University of Texas at Austin

Department of Chemical Engineering

Fall 2006

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Overview

• How Solar Energy Works• Types of Photovoltaic Systems

– Flat-plate and Concentrator• Current Applications• Solar Economics

– Price Trends– Costs– The Energy Payback Time

• Advances in Technology– Thin-film– PV roofing panels– Nanomaterials

How does solar energy work?

• The Photoelectric effect

• The PV cell layered with positive and negative charged semiconductor material

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Photovoltaic Systems

• System is constructed of Arrays

• There are two types of systems– Flat Plate Systems

• System can be in a fixed position or moving

• Makes use of Direct and Diffuse sun light

– Concentrator Systems• Moves relative to the sun• Requires less PV cell material

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Current Applications7

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Solar Energy Economics

• The cost of PV cells has been on decline since 70’s.• Decline due to advancements in efficiency and

manufacturing techniques• Residential equipment costs can range from 10K to

100K

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Energy Payback Time (EPBT)

• EPBT is length of time PV system takes to generate amount of energy put into system.

• Three factors determine the EPBT:– Amount of illumination received by PV cells– Conversion efficiency of PV cell– Manufacturing technology used to make PV

cell

Manufacturing Methods

• There are three methods to produce PV cells– Process cells on wafers sawed from silicon ingots

• Ingots are either single or multicrystalline

– Process cells on silicon wafers cut from multicrystalline ribbons – Deposition of non-crystalline silicon on inexpensive substrates

Single-crystal silicon

Non-ribbon multicrystalline silicon

RibbonMulticrystalline

silicon

Cheap Substrate

(Cadmium Telluride)

EPBT (Years)

2.7 2.2 1.7 1.0

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Technological Advances

• Thin-Film Technology– PV cells are continually

processed on a sheet consisting of much less material than the typical PV cells.

• Copper Solar Cells– Thin-Film PV cells are

made with Cu to increase efficiencies greater than 12% compared to silicon

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Technological Advances

• Solar Roof Panels– Shingles are combined with

PV cells creating insulation that generates electricity

• Nanomaterials– Solar cells incorporating

nanomaterials are stronger, more flexible, and more efficient.

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References

• Fast Solar Energy Facts. 14 Nov. 2006 <http://www.solarbuzz.com/     FastFactsIndustry.htm>.

• Harlin, Kevin. "Building new power panels." The Times Union. LexisNexis     Academic. LexisNexis. 20 Nov. 2006 <http://web.lexis-nexis.com/     universe>.

• Konarka, Textronic to Develop Solar Thin-fil PV Fabric. (2005, September 29). Renewable Energy Access. Retrieved November 19, 2006, from http://www.renewableenergyaccess.com/rea/news/productstory?id=37

• "Nanomaterials and Cost-effective Manufacturing Technologies Hold Key to     Development of Photovoltaic Technologies." PR Newswire US. LexisNexis     Academic. LexisNexis. 20 Nov. 2006 <http://web.lexis-nexis.com/     universe>.

• PV Markets. 20 Nov. 2006 <http://www.ece.umr.edu/power/Energy_Course/energy/     Renewables/pv/French_site/pvmark.html>.

• Recent Advancements in Solar Panel Technology by Shell Solar. 20 Nov. 2006     <http://www.solarexpert.com/PVadvancements.html>.

• Residential Solar Power Costs & Savings. 15 Nov. 2006     <http://www.borregosolar.com/home/solar-power-costs-savings.php>.

• Solar Energy Technologies Program. (2006,April 13). Retrieved November 10, 2006, from U.S. Department of Energy Web site: http://www1.eere.energy.gov/solar/photovoltaics.html

Images• Images Courtesy of

1 – www.google.com 2 – www.faqs.com 3 - http://www1.eere.energy.gov/solar/ 4 - http://www1.eere.energy.gov/solar/ 5 - http://www1.eere.energy.gov/solar/ 6 - http://www1.eere.energy.gov/solar/ 7 - http://www.solarserver.de/solarmagazin/anlage-e.html 8 – www.windturbine-1.com 9 – www.treehugger.com 10 - http://www.jaxa.jp/missions/projects/sat/astronomy/solar_b/index_e.html 11 – www.palacefarm.com 12 - http://howto.altenergystore.com 13 - http://www.che.utexas.edu/course/che379&384/Topic8_3.pp 14 - http://www.ece.umr.edu/power/ Energy_Course/energy/Renewables/pv/French_site/overview.html 15 - http://www1.eere.energy.gov/solar/ 16 - http://www.renewableenergyaccess.com/rea/news/productstory?id=37 17- http://www.solarexpert.com/PVadvancements.htm 18- http://www.solar-components.com/pvshingl.htm 19- http://newsroom.spie.org/x4436.xml