1. Plastic solar cells??? Ginger Lab – Department of Chemistry, University of Washington – Seattle, WA 98195  Boxed area:  13,500 mi 2  10% efficient solar cells would provide  3 TW power every year 3 TW = 250 light bulbs per person [40W bulbs]  Rooftop capacity: 18% of total energy 2 0.54 TW = 45 light bulbs per person [40W bulbs] (Left) Map of the USA showing the land area we need to cover with 10% efficient solar cells to provide our energy needs. Why do we need LOTS of solar cells? As shown above, solar cells can provide a direct conversion of energy from the sun into electricity – a form of energy we can use for power. Solar cells are the only renewable energy source that have the capacity to supply the energy to meet growing demand.  If we can cover the square area below with 10% efficient solar cells, we could meet our nation’s current energy needs. What are the advantages of plastic solar cells? Plastic wrap:  North America produces enough polyethylene 4 every year 5 to cover Arizona 4 times Daily newspaper circulation 6 :  Daily Top 10 Papers totals  10 million papers (320 ft 2 / paper)   300 days of newspaper would cover the boxed area Roadways:  25% of US highways covered with 10% efficient solar cells = 100% of the nation’s electricity 2 How do solar cells generate electricity? Batteries use stored energy to generate electricity Solar cells convert sunlight directly into electricity Is there an alternative to silicon-based solar cells? Si ingot 7 Great! But why aren’t current solar cells cost-competitive on the market? C&EN / Konarka www.stanford.edu/group/mcgehee/research.html Reel-to-reel printing Flexible substrates = $ References: 1: http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter4.pdf 2: http://www1.eere.energy.gov/solar/pdfs/set_myp_2007-2011_proof_1.pdf 3: https://www.cia.gov/library/publications/the-world-factbook/print/us.html 4: 30 billion pounds: http://www.the-innovation-group.com/ChemProfiles/Polyethylene-HD.htm 5: given 0.5 mil thickness of “Glad wrap” = ~12.5 microns thick = http://www.glad.com/faqs/plasticwrap.php 6: Circulation data USA Today. 7: http://www.ami.ac.uk/courses/ami4202_mdesign/u02/images/SingleCrystalSiliconIngot.jpg This poster includes work supported by the National Science Foundation (DMR-0120967, DMR-044942, the Graduate Research Fellowship Program, and the Integrative Graduate Education and Research Traineeship), the Air Force Office of Scientific Research, the Department of Energy, the Camille Dreyfus Teacher-Scholar Awards Program, the Research Corporation, and the Alfred P. Sloan Foundation. The Ginger Research Group (Dept. of Chemistry, University of Washington) also thanks the Center for Nanotechnology at the University of Washington for sponsorship at Shoreline Solarfest 2009.  Easily mass produced (newspapers, plastic wrap)  Plastic is cheaper than silicon, especially for large areas  Printable (onto roadways?) = $$$$ $ $ $ Energy intensive fabrication Purification ~3 TW 1 (total power) We want Really Big Solar Cells