Advantages of pumped hydro units include simple operation, high reliability, low maintenance, long life, quick start from a standstill, and economic genera- tion of peaking electrical energy. Several such systems are in operation in the United States. Power-generat- ing capacities of these systems vary between 5 mega- watts and 2,000 megawatts or higher. The overall effi- ciencies of these power plants vary between 65 and 90 percent (these figures include the efficiencies of pumps, hydraulic turbines, and generators, and losses from the upper reservoir). In spite of the technical and economic viability of pumped hydro, the require- ment of a specific type of topography and some envi- ronmental concerns limit its application. To over- come these problems, underground pumped hydro storage can be used. In this case a large cavern or an aquifer can be used as the lower reservoir. Solar Heat Storage When converted into heat, solar energy can be stored in the form of sensible heat and latent heat. Sensible heat is stored in a material by raising its temperature. The amount of sensible heat stored in a material is equal to the product of the mass, specific heat, and the temperature rise of the material. The most com- mon sensible heat storage materials include water, propylene glycol, rocks, and molten salts. Water has the highest specific heat value. The higher the tem- perature rise, the greater the amount of heat stored. However, the highest temperature is limited by the properties of the material. Thermal energy can also be stored as latent heat in a material when it changes phase, as from solid to liq- uid or liquid to vapor. Some materials also change phase from solid to vapor directly or from one solid phase to another. The amount of latent heat stored in a material is equal to the product of the mass of the material and its latent heat. Because materials change phase at a constant temperature, latent heat is stored and retrieved at a fixed temperature known as the transition temperature. Some common phase change materials (PCMs) used for heat storage are paraffin waxes, Glauber’s salt (sodium sulfate decahydrate), calcium chloride hexahydrate, sodium acetate tri- hydrate, and cross-linked high-density polyethylene. Solar heat storage has major applications in space heating, crop drying, cooking, electric power genera- tion, and industrial process heat. Heat storage in water is the most economical and well-developed tech - nology. Hot water is stored in tanks made of glass- or stone-lined steel, fiberglass,reinforced polymer (plas - tic), concretewithplasticliner,andwood.The storage tanks may be located above or below ground. In North America and China, aquifers have been used for long-term storage of hot water. Molten nitrate salt (50 percent sodium nitrate, 50 percent potassium ni- trate), also known as Draw salt, which has a melting point of 222° Celsius, has been used as a storage mate- rial for a solar thermal power system in anexperiment in Albuquerque, New Mexico. This was the first com- mercial demonstration of generating power from storage. Solar Two, a 10-megawatt solar thermal power demonstration project in Barstow, California, also was designed to use this molten salt to store solar energy. It led to the development of Solar Tres Power Tower near Seville, Spain. PCMs encapsulated in tubes, trays, rods, panels, balls, canisters, and tiles have been used for solar space-heating applications. The most common PCMs used are hydrated salts of sodium sulfate, sodium thiosulfate, sodium acetate, barium hydroxide, mag- nesium chloride, and magnesium nitrate. For build- ing space-heating applications, PCM can be encapsu- lated in the building components themselves. They can be incorporated in the ceiling, wall,orfloor of the building. For example, paraffin wax mixtures have been used for heat storage in wallboards. D. Yogi Goswami and Chand K. Jotshi Further Reading Baxter, Richard. Energy Storage: A Nontechnical Guide. Tulsa, Okla.: PennWell Books, 2006. Dell, Ronald M., and David A. J. Rand. Understanding Batteries. Cambridge, England: Royal Society of Chemistry, 2001. Harper, Gavin D. J. Fuel Cell Projects for the Evil Genius. New York: McGraw-Hill, 2008. Kreith, Frank, and D. Yogi Goswami, eds. Handbook of Energy Efficiency and Renewable Energy. Boca Raton, Fla.: CRC Press, 2007. Lane, George A., ed.Solar Heat Storage: Latent Heat Ma- terials. 2 vols. Boca Baton, Fla.: CRC Press, 1983. Linden, David, and Thomas B. Reddy, eds. Handbook of Batteries. 3d ed. New York: McGraw-Hill, 2001. O’Hayre, Ryan, Suk-Won Cha, Whitney Colella, and Fritz B. Prinz. Fuel Cell Fundamentals. 2d ed. Ho- boken, N.J.: John Wiley & Sons, 2009. See also: Electrical power; Fuel cells; Hydroenergy; Photovoltaic cells; Solar energy. 370 • Energy storage Global Resources Global Resources Global Resources Volume 2 Environment and Natural Resources Division - Mica Editor Craig W. Allin Cornell College Salem Press Pasadena, California Hackensack, New Jersey Editor in Chief: Dawn P. Dawson Editorial Director: Christina J. Moose Manuscript Editor: Christopher Rager Acquisitions Editor: Mark Rehn Research Supervisor: Jeffry Jensen Photo Editor: Cynthia Breslin Beres Production Editor: Andrea E. Miller Page Design and Layout: James Hutson Additional Layout: Mary Overell and William Zimmerman Editorial Assistant: Brett Weisberg Cover photo: ©Tebnad/Dreamstime.com Copyright © 1998, 2010, by Salem Press All rights in this book are reserved. 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ISBN 978-1-58765-644-6 (set : alk. paper) — ISBN 978-1-58765-645-3 (vol. 1 : alk. paper) — ISBN 978-1-58765- 646-0 (vol. 2 : alk. paper) — ISBN 978-1-58765-647-7 (vol. 3 : alk. paper) — ISBN 978-1-58765-648-4 (vol. 4 : alk. paper) 1. Natural resources. I. Allin, Craig W. HC85.E49 2010 333.703—dc22 2010001984 printed in the united states of america Contents Common Units of Measure . . . . . . . . . . xxxvii Complete List of Contents . . . . . . . . . . . . xliii Environment and Natural Resources Division. . . . . . . . . . . . . . . . . . . . . 371 Environmental biotechnology . . . . . . . . . . 372 Environmental degradation, resource exploitation and . . . . . . . . . . . . . . . . 375 Environmental engineering . . . . . . . . . . . 379 Environmental ethics . . . . . . . . . . . . . . . 381 Environmental impact statement . . . . . . . . 384 Environmental law in the United States . . . . . 384 Environmental movement . . . . . . . . . . . . 390 Environmental Protection Agency . . . . . . . . 394 Erosion and erosion control . . . . . . . . . . . 398 Ethanol . . . . . . . . . . . . . . . . . . . . . . 400 European Union Natura 2000 . . . . . . . . . . 404 Eutrophication . . . . . . . . . . . . . . . . . . 406 Evaporites . . . . . . . . . . . . . . . . . . . . . 406 Exclusive economic zones . . . . . . . . . . . . 407 Exxon Valdez oil spill . . . . . . . . . . . . . . . . 408 Farmland . . . . . . . . . . . . . . . . . . . . . 410 Federal Energy Regulatory Commission. . . . . 413 Federalism and resource management . . . . . 414 Feldspars. . . . . . . . . . . . . . . . . . . . . . 417 Fermi, Enrico . . . . . . . . . . . . . . . . . . . 420 Ferroalloys. . . . . . . . . . . . . . . . . . . . . 421 Fertilizers . . . . . . . . . . . . . . . . . . . . . 423 Fiberglass . . . . . . . . . . . . . . . . . . . . . 425 Fires . . . . . . . . . . . . . . . . . . . . . . . . 426 Fish and Wildlife Service, U.S. . . . . . . . . . . 429 Fisheries . . . . . . . . . . . . . . . . . . . . . . 430 Flax . . . . . . . . . . . . . . . . . . . . . . . . 438 Floods and flood control . . . . . . . . . . . . . 441 Fluorite . . . . . . . . . . . . . . . . . . . . . . 446 Food chain . . . . . . . . . . . . . . . . . . . . 447 Food shortages . . . . . . . . . . . . . . . . . . 449 Ford, Henry . . . . . . . . . . . . . . . . . . . . 453 Forest fires. . . . . . . . . . . . . . . . . . . . . 454 Forest management. . . . . . . . . . . . . . . . 456 Forest Service, U.S. . . . . . . . . . . . . . . . . 458 Forestry . . . . . . . . . . . . . . . . . . . . . . 461 Forests . . . . . . . . . . . . . . . . . . . . . . . 464 France . . . . . . . . . . . . . . . . . . . . . . . 467 Freeze-drying of food. . . . . . . . . . . . . . . 471 Friends of the Earth International. . . . . . . . 472 Fuel cells. . . . . . . . . . . . . . . . . . . . . . 472 Gallium . . . . . . . . . . . . . . . . . . . . . . 475 Garnet . . . . . . . . . . . . . . . . . . . . . . . 476 Gases, inert or noble . . . . . . . . . . . . . . . 477 Gasoline and other petroleum fuels . . . . . . . 480 Gems. . . . . . . . . . . . . . . . . . . . . . . . 482 General Mining Law . . . . . . . . . . . . . . . 487 Genetic diversity . . . . . . . . . . . . . . . . . 488 Genetic prospecting . . . . . . . . . . . . . . . 490 Genetic resources . . . . . . . . . . . . . . . . . 490 Geochemical cycles . . . . . . . . . . . . . . . . 494 Geodes. . . . . . . . . . . . . . . . . . . . . . . 497 Geographic information systems. . . . . . . . . 498 Geology . . . . . . . . . . . . . . . . . . . . . . 500 Geothermal and hydrothermal energy . . . . . 503 Germanium . . . . . . . . . . . . . . . . . . . . 510 Germany. . . . . . . . . . . . . . . . . . . . . . 511 Getty, J. Paul. . . . . . . . . . . . . . . . . . . . 516 Geysers and hot springs. . . . . . . . . . . . . . 516 Glaciation . . . . . . . . . . . . . . . . . . . . . 518 Glass . . . . . . . . . . . . . . . . . . . . . . . . 520 Global Strategy for Plant Conservation . . . . . 523 Global 200. . . . . . . . . . . . . . . . . . . . . 524 Gneiss . . . . . . . . . . . . . . . . . . . . . . . 524 Gold . . . . . . . . . . . . . . . . . . . . . . . . 525 Gore, Al . . . . . . . . . . . . . . . . . . . . . . 530 Granite . . . . . . . . . . . . . . . . . . . . . . 531 Graphite . . . . . . . . . . . . . . . . . . . . . . 532 Grasslands . . . . . . . . . . . . . . . . . . . . . 535 Greece . . . . . . . . . . . . . . . . . . . . . . . 538 Green Revolution . . . . . . . . . . . . . . . . . 542 Greenhouse gases and global climate change . . . . . . . . . . . . . . . . . . . . . 544 Greenpeace . . . . . . . . . . . . . . . . . . . . 548 Groundwater . . . . . . . . . . . . . . . . . . . 548 Guano . . . . . . . . . . . . . . . . . . . . . . . 550 Guggenheim family . . . . . . . . . . . . . . . . 552 Gypsum . . . . . . . . . . . . . . . . . . . . . . 553 Haber-Bosch process . . . . . . . . . . . . . . . 556 Hall, Charles Martin . . . . . . . . . . . . . . . 557 Hall-Héroult process . . . . . . . . . . . . . . . 558 Hazardous waste disposal. . . . . . . . . . . . . 558 Health, resource exploitation and . . . . . . . . 563 Helium . . . . . . . . . . . . . . . . . . . . . . 568 Hemp . . . . . . . . . . . . . . . . . . . . . . . 570 Herbicides. . . . . . . . . . . . . . . . . . . . . 573 Hill, James Jerome . . . . . . . . . . . . . . . . 575 Horticulture. . . . . . . . . . . . . . . . . . . . 576 xxxv Hydroenergy . . . . . . . . . . . . . . . . . . . 579 Hydrogen . . . . . . . . . . . . . . . . . . . . . 583 Hydrology and the hydrologic cycle . . . . . . . 585 Hydroponics. . . . . . . . . . . . . . . . . . . . 588 Hydrothermal solutions and mineralization . . . 590 Ickes, Harold . . . . . . . . . . . . . . . . . . . 592 Igneous processes, rocks, and mineral deposits. . . . . . . . . . . . . . . . . . . . . 592 Incineration of wastes. . . . . . . . . . . . . . . 597 India . . . . . . . . . . . . . . . . . . . . . . . . 600 Indium. . . . . . . . . . . . . . . . . . . . . . . 605 Indonesia . . . . . . . . . . . . . . . . . . . . . 606 Industrial Revolution and industrialization . . . 610 Integrated Ocean Drilling Program . . . . . . . 615 Intergovernmental Panel on Climate Change . . . . . . . . . . . . . . . . . . . . . 615 Internal combustion engine . . . . . . . . . . . 617 International Association for Impact Assessment . . . . . . . . . . . . . . . . . . . 619 International Atomic Energy Agency . . . . . . 620 International Union for Conservation of Nature . . . . . . . . . . . . . . . . . . . . 621 Iodine . . . . . . . . . . . . . . . . . . . . . . . 621 Iran . . . . . . . . . . . . . . . . . . . . . . . . 623 Iron . . . . . . . . . . . . . . . . . . . . . . . . 628 Irrigation . . . . . . . . . . . . . . . . . . . . . 634 Isotopes, radioactive . . . . . . . . . . . . . . . 636 Isotopes, stable . . . . . . . . . . . . . . . . . . 639 Italy . . . . . . . . . . . . . . . . . . . . . . . . 641 Ivory . . . . . . . . . . . . . . . . . . . . . . . . 645 Izaak Walton League of America. . . . . . . . . 648 Jackson, Wes. . . . . . . . . . . . . . . . . . . . 649 Japan. . . . . . . . . . . . . . . . . . . . . . . . 650 Kaiser, Henry J. . . . . . . . . . . . . . . . . . . 655 Kazakhstan . . . . . . . . . . . . . . . . . . . . 655 Kyanite. . . . . . . . . . . . . . . . . . . . . . . 660 Kyoto Protocol . . . . . . . . . . . . . . . . . . 662 Lakes. . . . . . . . . . . . . . . . . . . . . . . . 664 Land ethic . . . . . . . . . . . . . . . . . . . . . 667 Land Institute . . . . . . . . . . . . . . . . . . . 668 Land management . . . . . . . . . . . . . . . . 670 Land-use planning . . . . . . . . . . . . . . . . 673 Land-use regulation and control. . . . . . . . . 675 Landfills . . . . . . . . . . . . . . . . . . . . . . 677 Landsat satellites and satellite technologies . . . . . . . . . . . . . . . . . . 680 Law of the sea . . . . . . . . . . . . . . . . . . . 685 Leaching. . . . . . . . . . . . . . . . . . . . . . 686 Lead . . . . . . . . . . . . . . . . . . . . . . . . 688 Leopold, Aldo. . . . . . . . . . . . . . . . . . . 692 Lime . . . . . . . . . . . . . . . . . . . . . . . . 693 Limestone . . . . . . . . . . . . . . . . . . . . . 695 Lithium . . . . . . . . . . . . . . . . . . . . . . 697 Lithosphere . . . . . . . . . . . . . . . . . . . . 698 Livestock and animal husbandry. . . . . . . . . 699 Los Angeles Aqueduct . . . . . . . . . . . . . . 702 Maathai, Wangari . . . . . . . . . . . . . . . . . 704 McCormick, Cyrus Hall. . . . . . . . . . . . . . 705 Magma crystallization. . . . . . . . . . . . . . . 706 Magnesium . . . . . . . . . . . . . . . . . . . . 708 Magnetic materials . . . . . . . . . . . . . . . . 712 Manganese . . . . . . . . . . . . . . . . . . . . 713 Manhattan Project . . . . . . . . . . . . . . . . 716 Manufacturing, energy use in . . . . . . . . . . 717 Marble . . . . . . . . . . . . . . . . . . . . . . . 720 Marine mining . . . . . . . . . . . . . . . . . . 722 Marine vents. . . . . . . . . . . . . . . . . . . . 724 Mercury . . . . . . . . . . . . . . . . . . . . . . 725 Metals and metallurgy . . . . . . . . . . . . . . 728 Metamictization . . . . . . . . . . . . . . . . . . 731 Metamorphic processes, rocks, and mineral deposits . . . . . . . . . . . . . . . . 732 Methane . . . . . . . . . . . . . . . . . . . . . . 738 Methanol . . . . . . . . . . . . . . . . . . . . . 739 Mexico. . . . . . . . . . . . . . . . . . . . . . . 741 Mica . . . . . . . . . . . . . . . . . . . . . . . . 745 xxxvi Global Resources Common Units of Measure Common prefixes for metric units—which may apply in more cases than shown below—include giga- (1 billion times the unit), mega- (one million times), kilo- (1,000 times), hecto- (100 times), deka- (10 times), deci- (0.1 times, or one tenth), centi- (0.01, or one hundredth), milli- (0.001, or one thousandth), and micro- (0.0001, or one mil- lionth). Unit Quantity Symbol Equivalents Acre Area ac 43,560 square feet 4,840 square yards 0.405 hectare Ampere Electric current A or amp 1.00016502722949 international ampere 0.1 biot or abampere Angstrom Length Å 0.1 nanometer 0.0000001 millimeter 0.000000004 inch Astronomical unit Length AU 92,955,807 miles 149,597,871 kilometers (mean Earth-Sun distance) Barn Area b 10 –28 meters squared (approx. cross-sectional area of 1 uranium nucleus) Barrel (dry, for most produce) Volume/capacity bbl 7,056 cubic inches; 105 dry quarts; 3.281 bushels, struck measure Barrel (liquid) Volume/capacity bbl 31 to 42 gallons British thermal unit Energy Btu 1055.05585262 joule Bushel (U.S., heaped) Volume/capacity bsh or bu 2,747.715 cubic inches 1.278 bushels, struck measure Bushel (U.S., struck measure) Volume/capacity bsh or bu 2,150.42 cubic inches 35.238 liters Candela Luminous intensity cd 1.09 hefner candle Celsius Temperature C 1° centigrade Centigram Mass/weight cg 0.15 grain Centimeter Length cm 0.3937 inch Centimeter, cubic Volume/capacity cm 3 0.061 cubic inch Centimeter, square Area cm 2 0.155 square inch Coulomb Electric charge C 1 ampere second xxxvii Unit Quantity Symbol Equivalents Cup Volume/capacity C 250 milliliters 8 fluid ounces 0.5 liquid pint Deciliter Volume/capacity dl 0.21 pint Decimeter Length dm 3.937 inches Decimeter, cubic Volume/capacity dm 3 61.024 cubic inches Decimeter, square Area dm 2 15.5 square inches Dekaliter Volume/capacity dal 2.642 gallons 1.135 pecks Dekameter Length dam 32.808 feet Dram Mass/weight dr or dr avdp 0.0625 ounce 27.344 grains 1.772 grams Electron volt Energy eV 1.5185847232839 × 10 –22 Btus 1.6021917 × 10 –19 joules Fermi Length fm 1 femtometer 1.0 × 10 –15 meters Foot Length ft or ′ 12 inches 0.3048 meter 30.48 centimeters Foot, cubic Volume/capacity ft 3 0.028 cubic meter 0.0370 cubic yard 1,728 cubic inches Foot, square Area ft 2 929.030 square centimeters Gallon (British Imperial) Volume/capacity gal 277.42 cubic inches 1.201 U.S. gallons 4.546 liters 160 British fluid ounces Gallon (U.S.) Volume/capacity gal 231 cubic inches 3.785 liters 0.833 British gallon 128 U.S. fluid ounces Giga-electron volt Energy GeV 1.6021917 × 10 –10 joule Gigahertz Frequency GHz — Gill Volume/capacity gi 7.219 cubic inches 4 fluid ounces 0.118 liter xxxviii Global Resources Unit Quantity Symbol Equivalents Grain Mass/weight gr 0.037 dram 0.002083 ounce 0.0648 gram Gram Mass/weight g 15.432 grains 0.035 avoirdupois ounce Hectare Area ha 2.471 acres Hectoliter Volume/capacity hl 26.418 gallons 2.838 bushels Hertz Frequency Hz 1.08782775707767 × 10 –10 cesium atom frequency Hour Time h 60 minutes 3,600 seconds Inch Length in or ″ 2.54 centimeters Inch, cubic Volume/capacity in 3 0.554 fluid ounce 4.433 fluid drams 16.387 cubic centimeters Inch, square Area in 2 6.4516 square centimeters Joule Energy J 6.2414503832469 × 10 18 electron volt Joule per kelvin Heat capacity J/K 7.24311216248908 × 10 22 Boltzmann constant Joule per second Power J/s 1 watt Kelvin Temperature K –272.15 Celsius Kilo-electron volt Energy keV 1.5185847232839 × 10 –19 joule Kilogram Mass/weight kg 2.205 pounds Kilogram per cubic meter Mass/weight density kg/m 3 5.78036672001339 × 10 –4 ounces per cubic inch Kilohertz Frequency kHz — Kiloliter Volume/capacity kl — Kilometer Length km 0.621 mile Kilometer, square Area km 2 0.386 square mile 247.105 acres Light-year (distance traveled by light in one Earth year) Length/distance lt-yr 5,878,499,814,275.88 miles 9.46 × 10 12 kilometers Liter Volume/capacity L 1.057 liquid quarts 0.908 dry quart 61.024 cubic inches xxxix Common Units of Measure . Hydroenergy; Photovoltaic cells; Solar energy. 370 • Energy storage Global Resources Global Resources Global Resources Volume 2 Environment and Natural Resources Division - Mica Editor Craig W. Allin Cornell. National Standard for Permanence of Paper for Printed Library Materials, Z39.48-1992 (R1997). Library of Congress Cataloging-in-Publication Data Encyclopedia of global resources / Craig W. Allin,. efficiencies of pumps, hydraulic turbines, and generators, and losses from the upper reservoir). In spite of the technical and economic viability of pumped hydro, the require- ment of a specific type of