Solar Energy 1 Bruce Logue and Robert Chou

Solar Energy 1 Bruce Logue and Robert Chou The University of Texas at Austin Department of Chemical Engineering Fall 2006

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? 2 • The Photoelectric effect 3 • The PV cell layered with positive and negative charged semiconductor material

Photovoltaic Systems 4 • System is constructed of Arrays • There are two types of systems 5 – 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 6

Current Applications 7 9 8 10 11 12

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 10 K to 100 K 14 13

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 EPBT (Years) 15 Singlecrystal silicon Non-ribbon multicrystalline Multicrystalline silicon Cheap Substrate (Cadmium Telluride) 2. 7 2. 2 1. 0 Ribbon 1. 7

Technological Advances • Thin-Film Technology 16 – 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 17

Technological Advances • Solar Roof Panels – Shingles are combined with PV cells creating insulation that generates electricity 18 • Nanomaterials – Solar cells incorporating nanomaterials are stronger, more flexible, and more efficient. 19

References • • Fast Solar Energy Facts. 14 Nov. 2006 <http: //www. solarbuzz. com/ Fast. Facts. Industry. htm>. Harlin, Kevin. "Building new power panels. " The Times Union. Lexis. Nexis Academic. Lexis. Nexis. 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. Lexis. Nexis Academic. Lexis. Nexis. 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: //www 1. eere. energy. gov/solar/photovoltaics. html

Images • Images Courtesy of Ø Ø Ø Ø Ø 1 – www. google. com 2 – www. faqs. com 3 - http: //www 1. eere. energy. gov/solar/ 4 - http: //www 1. eere. energy. gov/solar/ 5 - http: //www 1. eere. energy. gov/solar/ 6 - http: //www 1. 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/che 379&384/Topic 8_3. pp 14 - http: //www. ece. umr. edu/power/ Energy_Course/energy/Renewables/pv/French_site/overview. html 15 - http: //www 1. 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/x 4436. xml