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Solar Voltaic Energy. Outline. Overview of Solar Power How Photo-voltaic (PV) Cells Work How Solar PV Cells are Made Solar PV Applications Efficiencies Economics Facts & Trends Research. Solar Power Overview. http://en.wikipedia.org/wiki/Image:The_Sun_w920607.jpg. PV Solar Radiation.
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Outline • Overview of Solar Power • How Photo-voltaic (PV) Cells Work • How Solar PV Cells are Made • Solar PV • Applications • Efficiencies • Economics • Facts & Trends • Research
PV Solar Radiation http://en.wikipedia.org/wiki/Solar_cells
Light & the Photovoltaic Effect • Certain semiconductor materials absorb certain wavelengths • The shorter the wavelength the greater the energy • Ultraviolet light has more energy than infrared light • Crystalline silicon • Utilizes all the visible spectrum plus some infrared radiation • Heat vs. electrical energy • Light frequencies that is too high or too low for the semiconductor to absorb turn into heat energy instead of electrical energy
Cross Section of PV Cell http://en.wikipedia.org/wiki/Solar_cells
Solar Cell Construction • Materials • Crystalline Silicon • Gallium Arsenide (more expensive) • Grown into large single-crystal ingots • Sawed into thin wafers • 2 wafers are bonded together (p-n junction) • Wafers grouped into panels or arrays http://en.wikipedia.org/wiki/Solar_panel
Growing Silicon Ingots Czochralski Process http://en.wikipedia.org/wiki/Czochralski_process
Drawing a Silicon Ingot http://www.answers.com/topic/silicon
Silicon Ingots & Wafers http://www.sumcosi.com/english/products/products2.html
Computer Chips on Wafer http://d0server1.fnal.gov/projects/silicon/www/svxwafer.jpeg
Silicon Solar Cell http://en.wikipedia.org/wiki/Image:Solar_cell.png
PV Cells have efficiencies approaching 21.5% Florida Solar Energy Center
Cells are the building block of PV systems Typically generate 1.5 - 3 watts of power Modules or panels are made up of multiple cells Arrays are made up of multiple modules A typical array costs about $5 – $6/watt Still need lots of other components to make this work Typical systems cost about $8/watt Solar PV Systems
PV Modules have efficiencies approaching 17% Florida Solar Energy Center
Solar Panel Solar panel by BP Solar at a German autobahn bridge http://en.wikipedia.org/wiki/Solar_panel
International Space Station Hubble Telescope Mars Rover Spacecraft
Remote Areas (Mexico) A solar panel in Marla, Cirque de Mafate, Réunion http://en.wikipedia.org/wiki/Solar_panel
Residential http://www.californiasolarco.com/photos_html/grid_tied/rootop_system/nevada-city-2-4.html
Commercial Solar Centre at Baglan Energy Park in South Wales http://www.c-a-b.org.uk/projects/tech1.htm
Solar Cell Efficiencies • Typical module efficiencies ~12% • Screen printed multi-crystalline solar cells • Efficiency range is 6-30% • 6% for amorphous silicon-based PV cells • 20% for best commercial cells • 30% for multi-junction research cells • Typical power of 120W / m2 • Mar/Sep equinox in full sun at equator http://en.wikipedia.org/wiki/Solar_cells
Solar Panel Efficiency • ~1 kW/m2 reaches the ground (sunny day) • ~20% efficiency 200W/m2 electricity • Daylight & weather in northern latitudes • 100 W/m2 in winter; 250 W/m2 in summer • Or 20 to 50 W/m2 from solar cells • Value of electricity generated at $0.08/kWh • $0.10 / m2 / day OR $83,000 km2 / day http://en.wikipedia.org/wiki/Solar_panel
World Largest PV Solar Plants [edit] http://en.wikipedia.org/wiki/Solar_panel
World Solar Power Production http://en.wikipedia.org/wiki/Solar_panel
Solar Cell Production Volume Sharp Corporation http://sharp-world.com/solar/generation/images/graph_2004.gif
Inverter Converts DC power from solar array to AC for use in your home Wiring Connects the system components Batteries Used to store solar-produced electricity for nighttime or emergency use Mainly used for remote sites that aren’t tied into the electrical grid Charge controller Prevents batteries from being over charged Disconnect switches Allows power from a PV system to be turned off Electrical meter Measures electrical production and use Often runs backward if system is attached to the electrical grid Solar PV Components Total system cost = ~$8.00 / watt
BATTERY Stand Alone Solar PV System
Net Metering • When your system produces more electricity than your home uses • electricity flows backward out to the grid • Meter runs backward and you get credit for the electricity you sell to the utility