Renewable Energy Electricity & Physics Basics Frank R. Leslie, B. S. E. E., M. S. Space Technology 1/24/2005, Rev. 1.0 (321)

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

1.1.0 Electricity: Introduction

1.1.1 Electricity: Voltage

1.1.2 Electricity: Current

1.1.3 Electricity: Resistance

1.1.3 Electricity: Power

1.1.3 Electricity: Energy

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

1.2.0 Physics: Introduction

1.2.Physics: Force

1.2.Physics: Torsion

1.2.Physics: Power

1.2.Physics: Energy

1.2.Physics: Light

1.2.Physics: Pulleys & Gears Mechanical shafts may be coupled together by pulleys and belts or directly by gears

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]

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

1.3.2 Equations E = IR = sqrt(P/R) FIX THIS I = E/R = sqrt(PFIX THIS P = EI = E 2 /R = I 2 R Energy = Pt, where t is time F = mA

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

References: Books Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, , TJ807.9.U6B76, ’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., , TJ820.G57, 621.4’5 Patel, Mukund R. Wind and Solar Power Systems. Boca Raton: CRC Press, 1999, 351 pp. ISBN , TK1541.P , ’2136 Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press, 2000, 911 pp. ISBN

References: Websites, etc. Wind Energy elist Wind energy home powersite elist geothermal.marin.org/ on geothermal energy rredc.nrel.gov/wind/pubs/atlas/maps/chap2/2-01m.html PNNL wind energy map of CONUS Elist for wind energy experimenters Site devoted to the decline of energy and effects upon population Federal Energy Regulatory Commission on OTEC systems telosnet.com/wind/20th.html solstice.crest.org/ dataweb.usbr.gov/html/powerplant_selection.html