11 1 12 b Mr Scott Schopke s Machines

11. 1. 12 b Mr. Scott Schopke’s Machines Mounted 1 ampere PV chargers keep batteries charged & ready to go! Photos by F. Leslie, 2004; courtesy of Scott Schopke Forklift (top) and Piling Grouting Drill Machine (left) 050203

11. 0 Solar Energy Frank R. Leslie, B. S. E. E. , M. S. Space Technology, LS IEEE 2/8/2010, Rev. 2. 0. 0 fleslie @fit. edu; (321) 674 -7377 www. fit. edu/~fleslie

In Other News. . . l Haggling continues over $1 B for home heating subsidies in US House l Senate: $11. 5 B for mass transit and rail projects l House: $12. 4 B for mass transit including $4. 6 B to buy transit equipment such as buses l House: $31 B to build and repair federal buildings, etc. l Pickens reports, “in December we had imported just under 380 million barrels of oil at a cost of $19. 3 billion. “ Then, “In January, according to the Department of Energy, we imported 408. 7 million barrels which cost the United States about $17 billion, so the transfer of wealth from America to foreign governments is continuing. “ 090209

11 Solar Energy Overview l Solar energy is best suited for sunny places to be able to save enough to ever pay off the equipment investment l Other possible locations might be where utility power isn’t available, and payback time doesn’t matter! l Climate records show the availability of this solar energy and must not be ignored when designing a system l Like all climates, the statistical variability requires that a “long” sample be used, perhaps five years to fifty years u You estimate the long term from what you have l Cloudy weather or persistent darkness (Alaska) requires storage to be able to provide energy at night and through low light conditions; Alaska solar energy systems must use wind or diesel energy; 6 months of storage costs too much! 080205

11. 0 About This Presentation l 11. 1 History l 11. 2 Incoming Solar Energy, or Insolation (note “o”, not “u”; incoming solar radiation) l 11. 3 Solar Resource Availability l 11. 4 Solar Variability l 11. 5 Roberts Hall Solar Modules l 11. 6 Solar Path Considerations l 11. 7 Solar Energy Systems Decomposition l 11 Conclusion 100208

11. 1 History of Solar Energy l 1500 BC Egyptian ruler Amenkotep III supposedly had “sounding statues” that emitted a tone when air inside was heated by the sun l 800 BC Plutarch noted that vestal virgins used metal cones to light ritual fires l 212 BC Archimedes purportedly used burning mirrors to set fire to ships according to Galen in De Temperamentis (see Mythbusters) l ~1700 AD French scientist, George Buffon, made multiple flat mirrors to concentrate light to a point. ~1747, he ignited a wood pile 195 ft away (wood ignites at ~250°C with flux of 4. 7 k. W/m 2) l ~1760 Swiss de Sanesure made a solar oven that reached 320°F l 1837 Herschel used a solar oven to cook food at 240°F in South Africa l ~1860 Bessemer made a solar furnace that melted copper and zinc l ~1860 Augustin Mouchet built “axicons” (simple cone) to focus on a tube; built steam engines with a 40 ft 2 reflector 090210

11. 1. 1 History of Solar Energy, part 2 l 1868 John Ericsson built a solar powered 2. 5 HP engine that used a parabolic reflector l 1878 William Adams built a 2 k. W solar water pump near Bombay, India l 1880 E. Weston suggested a thermocouple for generating electricity l 1882 Abel Pifre & Mouchot demonstrated a steam engine at Tucleries Garden, Paris, driving a printing press to supply fair visitors with handouts l 1896 C. G. O. Barr patented an idea to place mirrors on railroad cars, precursor of solar towers l 1912 Prof. C. V. Boys & Frank Shuman built a 50 HP solar pumping engine at Meadi, Egypt 080130

11. 1. 2 1903 Meadi, Egypt Solar Engine http: //www. solarenergy. com/info_history. html http: //www. freeenergynews. com/Directory/Solar/Tesla/Experimentor_1916_Solar_Article. pdf photo follows on next page 080205

http: //www. freeenergynews. com/Directory/Solar/Tesla/Experimentor_1916_Solar_Article. pdf

11. 2 How Much Solar Energy Strikes Earth? The sun gives off 3. 90 x 1026 Watts (Universe 4 th edition, p 585) The earth intercepts energy equal to a disk equal to the earth's diameter Earth's radius is 3, 393, 000 meters (WGS 84 value is 6, 378, 137 m/2) Earth's solar interception area is (3. 14)(3, 393, 000)^2 This equals 3. 62 x 1013 m 2 The amount of power crossing earth's orbit is 1388 watts / m 2 Therefore: the earth intercepts 5. 02 x 1016 watts We see that the earth intercepts 50 quadrillion watts of solar power each day We could use some of this energy without depleting the sun! 080205

11. 2. 1 Solar Energy on Earth l Energy from our sun (1366 W/m^2) is filtered through the atmosphere and is received at the surface at ~1000 watts per square meter or less; average is 345 W/m^2 l Air, clouds, and haze reduce the received surface energy l Capture is from heat (thermal energy) and by photovoltaic cells yielding direct electrical energy l Solar “constant” varies l 1366. 1 W/m^2 Atlas 3 l 1367 W/m^2 NREL l 1376 W/m^2 NOAA l 1388 W/m^2 NASA 080130

11. 2. 2 Solar Spectrum peaks at ~. 5 micron 050203 http: //www. lowell. edu/users/jch/workshop/gjr-p 1. html

11. 2. 2 Solar Spectrum changes at surface 080130 http: //www. globalwarmingart. com/images/thumb/4/4 c/Solar_Spectrum. png/672 px-Solar_Spectrum. png

11. 2. 3 Radiation paths are critical Over a year, radiation peaks near the summer solstice. Direct radiation is straight from the sun, while global adds reflected light from the clouds and other objects. 060201 http: //www. jxj. com/magsandj/rew/2000_02/images/solar_radiation_350. jpg

11. 2. 4 Pyranometers measure light intensity Sensitivity approximately 70 µV/Wm-² The upper dome contains the incident surface sensor, while the lower sensor measures only indirect light intensity from ground 070206 http: //www. omniinstruments. co. uk/airweath/cm 7 b. jpg

11. 3. 1 How Much Sun is There in the World? Equator http: //www. oksolar. com/images/world_performance. gif 070206

11. 3. 2 How Much Sun is There in the US? 030204

11. 3. 3 How Much Sun is There in the US? k. Wh/m 2; June average over 30 years 050208 http: //www. eren. doe. gov/pv/solarresource. html

11. 3. 4. 1 How Much Sun is There in the US? 030205 http: //www. wattsun. com/images/insolation_maps/Flat_Plate_Tilted_South_at_Latitudeminus 15_Degrees_JUN. gif

11. 3. 4. 2 Insolation in Melbourne/ Palm Bay Area l The annual solar energy available in Palm Bay, Florida is estimated at 1715 k. Wh/square meter-year Irradiance from this FSEC plot shows the higher energy level available with a tilted collector. Note the ragged effects of clouds in the sun path 050208

11. 4. 1 Variations in Surface Energy Affect Potential Capture l A flat plate absorber aimed normal to the sun (plate at 90 degrees to incoming sunlight) will receive energy according to the amount of atmosphere along the path (overhead air mass Ξ 1) l The received energy varies around the World due to local cloud attenuation; in Florida, direct normal radiation is 4. 0 to 4. 5 k. Wh/(m 2 day) l Throughout the Contiguous United States (CONUS), daily solar energy varies from <3. 0 to 7. 0 k. Wh/(m 2 day) 080205

11. 4. 2 Cloud Variability vs. Location l Cloudiness attenuates the insolation by reflection and absorption l Orographic effects from nearby mountains may cause local cloud generation or limit the hours of sunlight by shadows u Rattenburg, Austria installed reflectors on a blocking mountain to bounce light into the town http: //findarticles. com/p/articles/mi_qn 4158/is_20050326/ai_n 13471484 l Lake and sea breeze effects generate clouds that will block or attenuate the sun’s intensity as received l Differences of just a few miles can significantly change the solar collector system effectiveness l Placement of collectors is important 080205

11. 4. 3 Module mounting affects energy l Fixed modules must maximize energy absorption over a year unless they are to be manually adjusted (perhaps once a quarter) l Modules are normally tilted to the south (in the Northern Hemisphere) by the latitude angle if they are not to be moved; tilted to north in Southern Hemisphere l Near the equator, extra tilt is used to drain off rainwater and accumulated dirt without greatly affecting output l The PV module can be mounted on an axis parallel to the Earth’s axis and rotated by a clock drive or servomechanism l Avoid shadowing of the module cells or a string may not work l Two axis tracking uses balanced photocells and drive motors to tilt the mount to be normal to the sun throughout the day l Any mounting must also survive storm winds (130 mph in Melbourne, Florida) 080205

11. 4. 3. 1 Solar Module Annual Tilt NP Summer Solstice Spring Winter Solstice NP NP -23. 5° SP +23. 5° tilt NP SP SP Fall SP l Modules are tilted at latitude angle to be aimed at sun on equinoxes; at solstices, they are off by the obliquity angle 070206

11. 5. 1 Roberts Hall Solar Module l A 300 watt solar electric module is mounted at 28° latitude angle and facing south on the south end of the seventh floor roof (that’s 4 by 6 feet up there) u. A Campbell Scientific datalogger (specialized computer) collects all data each second u. The datalogger records the intensity, average output voltage, and current at one minute intervals u. The panel provides enough current to charge a 24 V battery and power the datalogger with 12 Vdc u. We download the data every 15 minutes, and process it for http: //my. fit. edu/wx_fit/roberts/RH. htm and for http: //my. fit. edu/wx_fit/realtime_data/fitroofdata. php 100211

11. 6. 1 Solar Path Calculations l Equations: see FSEC brochure: Mc. Cluney, Ph. D. , Ross. Sun Position in Florida. FSEC DN 4 83, Florida Solar Energy Center, Cape Canaveral, FL, 1985 l Website calculations u http: //www. susdesign. com/sunangle/ u http: //www-sci. lib. uci. edu/HSG/Ref. Calculators 4. html#SOLAR u http: //www. wattsun. com/resources/calculators/photovoltaic_tilt. htm 100211

You are here! To Sun Zenith (up) Zenith Angle To Sun North Pole Solar Declination Angle Horizontal Plane Latitude Angle Equatorial Plane Zeni Sun’s zenith angle is measured from local vertical Equator 11. 6. 1 Zenith Angle of Sun South Pole 070206 Boyle, p 25. is part of reading assignment for ENS 4300/ENS 5300

11. 6. 2 Optimum Solar Module Tilt l Website calculations Sun Altitude Array Tilt Array Points to: JAN 42 48 South FEB 51 39 South MAR 62 28 South APR 74 16 South MAY 82 8 South JUN 85 5 South JUL 82 8 South AUG 74 16 South SEP 62 28 South OCT 50 40 South NOV 42 48 South DEC PV ARRAY: SOLAR NOON TILT DATA Latitude = 28 Degrees North Month 39 51 South Array Tilt = 90 degrees - Sun Altitude http: //www. wattsun. com/resources/calculators/photovoltaic_tilt. html 050208

11. 7. 1 Solar Energy Systems Decomposition l What are the functions of a solar energy system? 030207

11. 7. 2 Solar Energy Systems Decomposition l What are the functions of a solar energy system? Collect & Distribute Energy A systems engineering technique 050207

11. 7. 3 Solar Energy Systems Decomposition l What are the functions of a solar energy system? Collect & Distribute Energy Start Collect Energy Regulate Energy Store Energy Control Energy Distribute Energy Use Energy Each function drives a part of the design, while the interfaces between them will be defined and agreed upon to ensure follow-on upgrades 030207

11 Conclusion: Solar Energy l Received solar energy varies widely as evidenced by climate records and vegetation l Dry desert areas indicate lots of sun and low moisture! l This variability affects the economic viability of a system l Solar energy systems are simple, robust, and easy to install and maintain l Solar modules are still expensive, approximately $3. 20/W (2010) for large 150 W modules to $16/W for small, dependent upon size; $5/W to install u. A 300 W module (4 x 6 ft) weighs 107 pounds and is harder to carry and install than smaller modules u. One person can readily install 120 W to 150 W modules 100208

Olin Engineering Complex 4. 7 k. W Solar PV Roof Array Questions? 080116

References: Books l Cheremisinoff, Paul N. and Thomas C. Regino. Principals & Applications of Solar Energy. Ann Arbor: Ann Arbor Science Publishers, Inc. , 1978. l Kreith, Frank, and Jan F. Kreider. Principles of Solar Engineering. NY: Mc. Graw Hill Book CO. , 1978. l Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, 1992. 0 262 02349 0, TJ 807. 9. U 6 B 76, 333. 79’ 4’ 0973. l Duffie, John and William A. Beckman. Solar Engineering of Thermal Processes. NY: John Wiley & Sons, Inc. , 920 pp. , 1991 l Patel, Mukund R. Wind and Solar Power Systems. Boca Raton: CRC Press, 1999, 351 pp. ISBN 0 8493 1605 7, TK 1541. P 38 1999, 621. 31’ 2136 l Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press, 2000, 911 pp. ISBN 0 12 656152 4. 030204

References: Websites, etc. www. fsec. ucf. edu Our local Cocoa, Florida experts at the Florida Solar Energy Center (FSEC) http: //www. usc. edu/dept/architecture/mbs/tools/vrsolar/Help/solar_concepts. html#sh_ang les http: //findarticles. com/p/articles/mi_qn 4158/is_20050326/ai_n 13471484 ___________________________________ www. dieoff. org. Site devoted to the decline of energy and effects upon population solstice. crest. org/ dataweb. usbr. gov/html/powerplant_selection. html 080204

Slide stockpile follows! Older slides follow this one. Look at these if you have interest or time. It’s difficult to decide what to leave out of the lecture to save time!