Transcript RE_EE_Basics

Renewable Energy
Electricity & Physics Basics
Frank R. Leslie,
B. S. E. E., M. S. Space Technology
1/24/2005, Rev. 1.0
fleslie @fit.edu; (321) 674-7377
www.fit.edu/~fleslie
Introduction
 Some students interested in renewable energy may not have had
electricity and/or physics courses
 This course requires some knowledge of these subjects, but only
the basics, which I provide here
 Electricity requires concepts of voltage, current, resistance, and
power
 Physics requires concepts of force, pressure, leverage, torque, and
power
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1.1.0 Electricity: Introduction
1.1.1 Electricity: Voltage
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1.1.2 Electricity: Current
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1.1.3 Electricity: Resistance
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1.1.3 Electricity: Power
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1.1.3 Electricity: Energy
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1.1.3 Electricity: Safety
 With voltages exceeding some 50 volts, there is
potentially a shock hazard that could lead to heart
irregularities and death!
 With low voltages but potentially high currents, you
could be burned by hot wires or arcing. This arc could
cause temporary blinding.
 Preclude shorting of wires, especially from large battery
systems.
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1.2.0 Physics: Introduction
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1.2.Physics: Force
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1.2.Physics: Torsion
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1.2.Physics: Power
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1.2.Physics: Energy
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1.2.Physics: Light
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1.2.Physics: Pulleys & Gears
 Mechanical shafts may be coupled together by pulleys
and belts or directly by gears
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1.2.Physics: Safety
 Hazards of pinching or crushing from strong forces may
exist!
 Use eye protection if flying parts might spin off breaking
machinery
 Wear eye protection when working with batteries to
avoid acid splashes
 Take care to keep hair and jewelry out of rotating or
moving parts
 Plan what will happen if something explodes or shatters
or otherwise goes horribly wrong! [news cliché]
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1.3.1 Units
 Voltage, V in volts, for voltage drops across a load
 Electromotive force, E in volts, source voltage from
battery, etc.
 Current, I in amperes or amps, flow of electrical charge
 Power, P in watts, ability to do work
 Energy, sometimes E or script E in watt-hours, work
done
 Note: capital for direct current and lower case for
alternating current
 Force, F in newtons or pounds force, for push or pull
 Torque, T in newton-meters or pound-feet, for twisting
or torsion
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1.3.2 Equations
 E = IR = sqrt(P/R) FIX THIS
 I = E/R = sqrt(P
FIX THIS
 P = EI = E2/R = I2R
 Energy = Pt, where t is time
 F = mA
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Conclusion
 You have seen the basics of electricity and physics as used in
renewable energy systems
 This information provides you with a basic understanding of how
electricity and physics principles support renewable energy systems
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References: Books
 Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, 1992. 0-262-02349-0,
TJ807.9.U6B76, 333.79’4’0973.
 Duffie, John and William A. Beckman. Solar Engineering of Thermal Processes. NY:
John Wiley & Sons, Inc., 920 pp., 1991
 Gipe, Paul. Wind Energy for Home & Business. White River Junction, VT: Chelsea
Green Pub. Co., 1993. 0-930031-64-4, TJ820.G57, 621.4’5
 Patel, Mukund R. Wind and Solar Power Systems. Boca Raton: CRC Press, 1999, 351
pp. ISBN 0-8493-1605-7, TK1541.P38 1999, 621.31’2136
 Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press,
2000, 911 pp. ISBN 0-12-656152-4.
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References: Websites, etc.
[email protected]. Wind Energy elist
[email protected]. Wind energy home powersite elist
geothermal.marin.org/ on geothermal energy
mailto:[email protected]
rredc.nrel.gov/wind/pubs/atlas/maps/chap2/2-01m.html PNNL wind energy map of CONUS [email protected]. Elist
for wind energy experimenters
www.dieoff.org. Site devoted to the decline of energy and effects upon population
www.ferc.gov/ Federal Energy Regulatory Commission
www.hawaii.gov/dbedt/ert/otec_hi.html#anchor349152 on OTEC systems
telosnet.com/wind/20th.html
www.google.com/search?q=%22renewable+energy+course%22
solstice.crest.org/
dataweb.usbr.gov/html/powerplant_selection.html
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