Encyclopedia of Global Resources part 145 ppsx

Electricity generated by renewable energy sources solar, wind, hydro, geo-thermal, and biomass energy is called “green” power.. Wind Farms A wind farm or wind power plant is a group of l

Energy from fossil fuels (coal, natural gas, and oil)

was in abundance and had essentially displaced wind

power The Atomic Energy Act of 1954 allowed private

companies to develop nuclear energy for peaceful

purposes However, Europe was developing more

wind-power technologies For instance, from 1956 to

1957 in Denmark, Johannes Juul built the world’s first

alternating current (AC) wind turbine, the very

effi-cient Gedser wind turbine The 1973 oil crisis, the

en-vironmental movement, and the dangers of atomic

energy led to renewed interest in wind energy, which

is a renewable energy source Electricity generated by

renewable energy sources (solar, wind, hydro,

geo-thermal, and biomass energy) is called “green” power

During the 1990’s, wind power was one of the

fastest-growing sources of energy

Wind Energy Technology

When the Sun warms areas of the Earth at different

rates and the various surfaces absorb or reflect the

ra-diation differently, there are differences in air

pres-sure As hot air rises, cooler air comes in to replace it

Wind, or air in motion, is the result Air has mass, and moving air contains kinetic energy, the energy of that motion

Windmills convert wind energy into mechanical power or electricity The modern electricity windmills are called wind turbines or wind generators In the wind turbine, wind turns two or three propeller-like rotor blades, which are the sails of the system When the blades move, energy is transferred to the rotor The wind shaft is connected to the rotor’s center, so both the rotor and shaft spin The rotational energy is thus transferred to the shaft, which spins an electrical generator at the other end

The ability to generate electricity is measured in units of power called watts A kilowatt represents 1,000 watts, a megawatt is 1 million watts, and a gigawatt rep-resents 1 billion watts Electricity consumption and production are described in kilowatt-hours Multi-plying the number of kilowatts by the number of hours equals the kilowatt-hours One kilowatt-hour equals the energy of one kilowatt produced or used for a period of one hour

The Green Mountain Energy Wind Farm at Brazos in Texas was completed in 2003 and contains 160 wind turbines.

The turbine’s size and the speed of the wind

through the rotor determine the output of the

tur-bine As of 2009, the world’s largest turbine was the

Enercon E-126, the first wind turbine with 6-megawatt

rated power Wind turbines can generate

electric-ity for an individual building or for widespread

dis-tribution by connecting to an electricity grid or

net-work

Wind Farms

A wind farm or wind power plant is a group of large

wind turbines (660 kilowatts and up) installed in

the same location to jointly capture wind and

pro-duce electricity There can be up to about one

hun-dred individual modules or turbines sited far apart

and covering an extended area of hundreds of square

kilometers Turbines can be added as the need arises

Individual modules connect with a medium-voltage

(usually 34.5-kilovolt) power collection system

Then a substation transformer increases the medium

voltage of electrical current for connection with a

high-voltage transmission system Wind farms are best

located in areas with consistent, strong, and

unob-structed winds, such as high plains, mountain passes,

and coastlines In rural, agricultural areas, the land

between the turbines can still be used for farming

As of 2009, the world’s second largest onshore

wind farm was Florida Power and Light’s Horse

Hol-low Wind Energy Center in Taylor and Nolan

coun-ties, Texas Completed in 2006, Horse Hollow has 421

turbines and delivers 735 megawatts of electricity at its

peak The world’s largest wind farm, as of October,

2009, was Roscoe Wind Farm in Texas, designed to

de-liver 781.5 megawatts from 627 turbines

In 2008, T Boone Pickens’s company, Mesa Power,

placed a $2 billion order with General Electric (GE)

for 667 wind turbines to be delivered in 2010 and

2011 Pickens, the legendary oil executive and energy

investor, planned to build the world’s largest wind

farm in Texas He also created the Pickens Plan,

which promotes generating up to 22 percent of the

nation’s electricity from wind, thus freeing up the

nat-ural gas supply to be used as transportation fuel and

reducing foreign oil dependence

Wind farms can also be sited offshore in the

shal-low waters of the oceans in order to capture the

stron-ger winds As of 2009, the world’s biggest offshore

wind farm was the Lynn and Inner Dowsing Wind

Farm near Skegness, Lincolnshire, England Each of

the fifty-four 3.6-megawatt turbines sits on a pylon

driven into the shallow seabed and turns a hub that is more than 80 meters above sea level

As of 2009, plans existed for even larger offshore farms When completed, Horns Rev 2 wind farm, sited

in the North Sea between 30 and 40 kilometers west of the westernmost tip of Denmark, would become the world’s biggest offshore wind farm, delivering 209 megawatts from ninety-five turbines, at a cost of about

$670 million The 1,000-megawatt London Array in the outer Thames Estuary, one of the three strategic areas the United Kingdom government has identified for offshore wind farm development, was scheduled for completion in the early 2010’s

In 2001, the Cape Wind Project was formally pro-posed The proposed $1 billion farm would cover 38.6 square kilometers on Horseshoe Shoal in Nantucket,

8 kilometers off Cape Cod in Massachusetts This loca-tion is one of the largest offshore areas with shallow water, which is very cost-effective because wind turbine foundation costs rise with increasing water depth and wave height The farm’s 130 wind turbines would pro-duce up to 420 megawatts of renewable wind energy that would, on average, provide 75 percent of the elec-tricity needed by Cape Cod, Nantucket, and Martha’s Vineyard The farm’s energy would be capable of re-placing 2.685 million barrels of oil per year After years

of rigorous and comprehensive review from federal and state agencies, the project was approved in 2009

Advantages and Disadvantages The first advantage of wind energy is that the fuel is free The main costs of generating electricity from wind are those of installation, operation, and mainte-nance The United States has an abundant supply

of wind power that can help promote energy inde-pendence from expensive imported energy and thus reduce national economic and security risks Since

1973, more than $7 trillion has been spent on foreign oil The wind industry has also created jobs and helped stabilize electricity costs Since 1980, the cost of wind energy has dropped more than 80 percent

Wind energy has significant long-term benefits for the environment, human health, and global climate change Wind is a clean, renewable energy resource that is inexhaustible and easily replenished by nature Wind power plants do not pollute the air or need waste cleanups like fossil-fuel and nuclear-generation plants, and wind turbines do not emit greenhouse gases or cause acid rain As of 2009, the wind-energy-generating capacity of the United States was 25,170

megawatts, enough electricity to power almost seven

million households To generate the equivalent of

that much energy, 112 million barrels of oil or 31.2

million metric tons of coal (a line of 9-metric-ton

trucks more than 22,000 kilometers long) would have

to be burned each year

A significant disadvantage is that wind is

inconsis-tent and intermitinconsis-tent It is variable power that does

not always blow at times of electrical demands To be

cost-effective, wind sites are located where both strong

winds and land are available, usually in remote

loca-tions, far from large population centers where

con-sumer demand is the greatest For instance, China’s

major wind-energy resources are located in the

North-ern China wind belt, including the sparsely

popu-lated Xinjiang Uygur and the windy grasslands of Nei

Monggol Even in locations where winds are strong,

there are wide differences in wind velocities over

rela-tively short distances

To meet these challenges, storage of surplus wind

energy and electrical distribution systems to transmit

this energy to consumers are necessary Wind power

can be stored in batteries, and technology already

ex-ists that can convert wind energy into fuels such as

eth-anol and hydrogen However, economic feasibility is a

major consideration Enhanced electrical

transmis-sion systems improve reliability for consumers, relieve

congestion in existing systems, and provide access to

new and remote wind-generation sources Typically,

large wind plants are connected to the local electric

utility transmission network In the European Union,

there is a proposal for a super grid of interconnected

wind farms in Western Europe, including Denmark,

England, Ireland, and France

On a smaller scale, distributed energy is a viable

so-lution Consumers can make their own wind power

with private wind turbine and batteries as backup As

more communities or individual consumers use

dis-tributed energy, they lower the costs of central wind

power plants and transmission systems Established in

1987, Southwest Windpower in Arizona is the world’s

leading producer of small wind turbines Applications

include offshore platform lighting, remote homes

and cabins, utility-connected homes and businesses,

water pumping, and telecommunications Their wind

generators often work as part of a hybrid wind-solar

battery-charging system Also, small domestic turbines

can complement power from a larger electrical power

system, and utility companies buy back any surplus

electricity

There are also aesthetic and environmental con-cerns surrounding the large-scale implementation of wind energy Local residents and public advocacy groups have often opposed wind farms because of the rotor noise, visual impact, and potential harm to property values and local wildlife and its habitats For instance, in 2001, residents concerned about the envi-ronment opposed the proposal of the Cape Wind Project, the first offshore wind farm in the country In many cases, technological advances and the appropri-ate siting of the wind generators away from populappropri-ated areas have mitigated the problems

The Future of Wind Energy Wind energy is already one of the fastest-growing en-ergy sources, and the market is forecast to expand in the future Wind power is affordable, readily avail-able, and renewable Wind energy technology has de-veloped to the point that it can compete successfully with conventional power generation technologies, such as oil, nuclear, coal, and most natural gas-fired generation

As of 2008, the world’s ten largest producers of wind power were the United States, Germany, Spain, China, India, Italy, France, the United Kingdom, Den-mark, and Portugal There is major wind-energy de-velopment globally, and in some countries, wind-power generation has been increasing exponentially In 2008,

in Australia, numerous wind farm projects were ap-proved, and wind power is expected to provide more than 20 percent of the country’s energy by 2020 China has been rapidly increasing its installed wind-power capacity each year since 2005, and estimates predicted that China would achieve a capacity of 100 gigawatts by 2020

Utility companies have increased investments in wind farms and wind technology In 2005, General Electric’s turbine business doubled, and by 2009, it was the leading U.S wind turbine supplier and a world leader, with more than ten thousand wind tur-bine installations worldwide, comprising more than 15,000 megawatts of capacity GE operates wind power manufacturing and assembly facilities in Spain, Can-ada, China, Germany, and the United States In 2008,

GE passed the $4 billion mark in investments in wind farms

Vestas, the Danish company that is the world’s lead-ing wind supplier, had $5.7 billion in revenues in

2008 In Denmark, wind energy equaled 20 percent of total energy consumption Vestas had installed more

than thirty-eight thousand wind turbines in sixty-two

countries on five continents to serve an estimated

forty-five million people worldwide By 2009, Vestas

was installing an average of one wind turbine every

three hours, twenty-four hours a day

In 2008, the U.S wind energy industry surpassed

previous records for installations and was second only

to the natural gas industry in adding new capacity

Enough new wind-power-generating capacity to

ser-vice more than two million homes, 8,500 megawatts,

was installed These wind projects increased the

na-tion’s entire wind-power-generating capacity to more

than 25,300 megawatts and equaled 42 percent of the

U.S.’s total power-producing capacity that was added

The new wind-energy capacity had the same effect as

taking more than seven million cars off the road or

preventing almost 40 million metric tons of carbon

emissions

Significantly, there has been increasing federal

gov-ernment support of wind power In 2008, the U.S

Department of Energy released its groundbreaking

technical report Twenty Percent Wind Energy by 2030:

Increasing Wind Energy’s Contribution to U.S Electricity

Supply More than one hundred people from

govern-ment, industry, utilities, and nongovernment

organi-zations worked on this report, which supports a

sce-nario in which by 2030, wind power would supply 20

percent of U.S electricity Other benefits would be to

reduce emissions of greenhouse gases by 25 percent,

avoid consumption of 15 trillion liters of water, cut

electric sector water consumption by 17 percent,

cre-ate $2 billion in local annual revenues through jobs

and other economic benefits, and reduce nationwide

natural gas use by 11 percent with savings of $86-$214

billion for gas consumers The Department of Energy

has also researched the use of wind energy for

hydro-gen production, water treatment and irrigation, and

hydropower applications

The American Recovery and Reinvestment Act of

2009 provided measures to benefit renewable energy,

including a Treasury Department grant program for

renewable energy developers, increased funding for

research and development, and a manufacturing tax

credit The ARRA also includes an extension of the

wind-energy production tax credit to December 31,

2012 Consumers are allowed federal tax credits for

energy efficiency, including tax credits of 30 percent

of the cost of residential small wind turbines placed in

service before December 31, 2016

Thomas W Weber, updated by Alice Myers

Further Reading

Baker, T Lindsay American Windmills: An Album of His-toric Photographs Norman: University of Oklahoma

Press, 2007

Bartmann, Dan, and Dan Fink Homebrew Wind Power:

A Hands-on Guide to Harnessing the Wind

Mason-ville, Colo.: BuckMason-ville, 2008

Chiras, Dan, Mick Sagrillo, and Ian Woofenden Power from the Wind: Achieving Energy Independence

Ga-briola Island, B.C.: New Society, 2009

Craddock, David Renewable Energy Made Easy: Free En-ergy from Solar, Wind, Hydropower, and Other Alterna-tive Energy Sources Ocala, Fla.: Atlantic, 2008 Evans, Robert L Fueling Our Future: An Introduction to Sustainable Energy New York: Cambridge University

Press, 2007

Foster, Robert, ed Wind Energy: Renewable Energy and the Environment Boca Raton, Fla.: CRC Press, 2009 Gillis, Christopher Wind Power Atglen, Pa.: Schiffer,

2008

Gipe, Paul Wind Energy Basics: A Guide to Home- and Community-Scale Wind-Energy Systems White River

Junction, Vt.: Chelsea Green, 2009

_ Wind Energy Comes of Age New York: Wiley,

1995

Nelson, Vaughn Wind Energy: Renewable Energy and the Environment Boca Raton, Fla.: CRC Press, 2009 Pickens, T Boone The First Billion Is the Hardest: Reflec-tions on a Life of Comebacks and America’s Energy Fu-ture New York: Crown Business, 2008.

Righter, Robert W Wind Energy in America: A History.

Norman: University of Oklahoma Press, 1996

Scientific American Energy for Planet Earth New York:

Author, 1990

Sorensen, Harry A Energy Conversion Systems New

York: J Wiley, 1983

Stiebler, Manfred Wind Energy Systems for Electric Power Generation Berlin: Springer, 2008.

Wizelius, Tore Developing Wind Power Projects: Theory and Practice Sterling, Va.: Earthscan, 2007.

Web Site U.S Department of Energy Wind

http://www.energy.gov/energysources/wind.htm See also: Athabasca oil sands; Biofuels; Department

of Energy, U.S.; Energy storage; Renewable and non-renewable resources; Resources for the Future; Solar energy

Wise use movement

Category: Historical events and movements

The wise use movement is a term generally used to

de-scribe individuals and groups that oppose either the

mainstream environmental movement or the federal

government’s policies on natural resources and land

use The movement has antecedents in earlier social

movements in the United States but became most active

during the 1990’s.

Definition

The term “wise use” was first used by conservationist

and forester Gifford Pinchot in his autobiography

Breaking New Ground (1947) Pinchot believed in

sus-tainable management and the multiple use of natural

resources—the base philosophy of the wise use

move-ment

Overview

The roots of the wise use movement can be traced to

the Sagebrush Rebellion, which occurred in the late

1970’s and early 1980’s in the West Cattle and mining

interests joined together to try to force the federal

government to return public domain lands to the

states, but they were unsuccessful in convincing

mem-bers of Congress to do so

In the late 1970’s, the timber industry became one

of the wise use movement’s supporters by leading

op-position to a proposed ban on logging near

Califor-nia’s Redwood National Park At about the same time,

private property owners in Yosemite National Park,

called inholders, began to organize against the

fed-eral government’s policies on land use Other groups

opposed the implementation of the Endangered

Spe-cies Act (1973) and the restrictions it placed on using

land considered wildlife habitat Added to the mix

were motorized recreational vehicle users who sought

to have wilderness areas opened up for their use

These varied interests came together under a

vari-ety of umbrella organizations that serve primarily as

clearinghouses for information Two men, Ron

Ar-nold and Alan Gottlieb, formed the Center for the

De-fense of Free Enterprise, which published The Wise Use

Agenda in 1989, outlining the movement’s core

phi-losophy Other umbrella groups, such as the Alliance

for America and the Blue Ribbon Coalition, work

to-ward reform of natural resource regulations,

target-ing the Endangered Species Act and wetlands desig-nations under the Clean Water Act, and seek to open

up more wilderness areas for public use by snowmo-biles and off-highway vehicles

It is impossible to estimate how many individuals are involved in or support the wise use movement, since there is no “membership” in the traditional sense Most individuals are counted as members be-cause they belong to an organization, such as the American Farm Bureau Federation, which supports one of the umbrella groups

Despite claims by members of some environmental organizations that the wise use movement is a front for industry interests, the majority of the groups, espe-cially those seeking changes in property rights poli-cies, appear to be genuinely grassroots-based Unlike organized business and trade lobbies, most wise use groups do not have the financial resources to engage

in strategies such as making contributions to candi-dates or maintaining a full-time lobbying presence in Washington, D.C Instead, they hold rallies, urge their members to write their representatives in Congress, and try to develop public support against regulations and policies which they oppose

Jacqueline Vaughn Switzer

See also: Conservation; Land-use regulation and control; Multiple-use approach; Pinchot, Gifford; Public lands; Sagebrush Rebellion; Takings law and eminent domain; Taylor Grazing Act

Wollastonite

Category: Mineral and other nonliving resources

Where Found Wollastonite is a common mineral; large deposits worldwide have been formed by contact metamor-phism where granite intrudes into limestone rocks Deposits formed in this way exist in the United States (California and New York), Mexico, Canada (Quebec and Ontario), China, and India Wollastonite is found

in volcanic ash and is formed by some volcanoes as molten lava interacts with limestone strata

Primary Uses Wollastonite is widely used in industry as functional filler Most commercially mined wollastonite is used

in the production of plastic polymers and ceramics It

is used in production of nylon 6 and polypropylene

Wollastonite is used in paints, construction products,

metallurgical processes, and the production of

med-ical bone cements and dental implants Ground

wol-lastonite is used in remedial treatment of soils

con-taminated by acid deposition Wollastonite has also

been used in friction products, including brake-drum

linings

Technical Definition

Wollastonite is a mineral composed of calcium,

oxy-gen, and silicon, with a chemical composition CaSiO3,

sometimes called calcium inosilicate or calcium

sili-cate Wollastonite has triclinic symmetry, forming

long, needlelike crystals with splintery or uneven

frac-tures It has a Mohs hardness of 5, similar to the

min-eral apatite and harder than fluorite It is soluble in

concentrated hydrochloric acid Some wollastonite

specimens fluoresce yellow or orange under

short-wave ultraviolet light It has a very low loss on ignition

(LOI) Pure wollastonite may be transparent and

col-orless or translucent and white; impurities cause a

pink, brown, or green coloration Its streak coloration

is white

Description, Distribution, and Forms

Wollastonite is a contact metamorphic mineral formed

when granitic magma intrudes into limestone or

do-lomite strata, creating what geologists call a “skarn”

deposit Skarn deposits of wollastonite usually

con-tain garnets and other minerals which are

removed and discarded during ore

process-ing Wollastonite is a common mineral, with

exploitable deposits known from many

lo-cales around the world At the close of the

twentieth century, most of the world’s

sup-ply was mined in China, the United States,

and India, with an unknown amount mined

and used in Russia Mining operations by

NYCO in Mexico were expected to supply

large amounts of wollastonite to the world

market in the early twenty-first century

The mineral wollastonite is composed of

long, single chains of silicates, sometimes

referred to as “pyroxenoid” structures

Tet-rahedral groups of silica are linked together

by calcium cations to form a long, crystal

chain Occasionally atoms of iron,

manga-nese, or magnesium replace calcium in the

crystal matrix These impurities cause pastel color-ations of yellow, pink, and green

Excellent wollastonite crystals are on display in most large science museums worldwide Many speci-mens displayed in museums have grown in vugs (cavi-ties inside rocks), allowing clear, perfect, large crys-tals of wollastonite to form Certain volcanic localities, including Monte Somma/Vesuvius, are renowned for wollastonite-filled vugs Wollastonite chunks are often used in museum displays of fluorescent minerals, where under ultraviolet light (“black light”) an other-wise unimpressive rock produces a bright orange col-oration Wollastonite specimens from Franklin, New Jersey, are especially well known from U.S museum displays and sought by private collectors because of their orange fluorescence

The aspect (length-to-width) ratio of wollaston-ite crystals determines the mineral’s application and hence value Powders, with low aspect ratios of 3:1, are used in metallurgy and in paints and coatings Wollastonite with high aspect ratios (ranging between 10:1 and 20:1) is more expensive than low-aspect wollastonite

History Prior to 1822, the mineral wollastonite was known in England as table spar or tabular spar It was renamed

at that time for William Hyde Wollaston, who had in-vestigated its physical and chemical properties in the late eighteenth century

Mineral specimens of wollastonite for scientific

Wollastonite is generally used in ceramics and plastic polymers (USGS)

play and comparison were collected in the nineteenth

century, when geologists used both “wollastonite” and

“table spar” to refer to field specimens Bustamite

(CaMnSi2O6)—a pink or red-colored inosilicate

mineral similar to wollastonite, but with manganese

alternating with calcium in the mineral lattice—was

referred to as “manganese wollastonite” by

mineralo-gists during the nineteenth and early twentieth

centu-ries Bustamite may be found with wollastonite in

metamorphic rocks

In the United States, wollastonite was

commer-cially mined beginning in 1933, in California, to use as

mineral wool Following the Korean War, the building

boom required increasing amounts of

wollastonite-containing construction products

In 2006, about 450,000 metric tons of refined

wol-lastonite were sold worldwide, with China the world’s

largest producer, followed by the United States and

India Demand for wollastonite grew during the last

several decades of the twentieth century, because it

became a substitute for asbestos (which posed health

risks and hence was not mined in the United States

after 2002) and because of its versatility as inexpensive

functional filler in paints, coatings, polymers, and

ceramics In the early twenty-first century, interest in

using wollastonite in bone cements and other

bio-medical applications grew

Obtaining Wollastonite

The extensive wollastonite deposits commercially

ex-ploited were all formed when granite intruded into

limestone or dolomite, causing large-scale contact

metamorphism Wollastonite is commonly

strip-mined, with some large open-pit operations and a few

underground mines using drill-and-blast methods

Small amounts of synthetic wollastonite are

pro-duced by sintering ground silica and calcite in rotary

kilns The wollastonite crystals produced are short

(have low aspect ratios) and powdery Synthetic

wol-lastonite costs more to produce than the natural

min-eral, and its use is usually restricted to metallurgical

and ceramic processes that require very pure and

extremely uniform crystals

Uses of Wollastonite

Wollastonite is a versatile nonmetallic mineral with

many different industrial uses Its industrial

applica-tions expanded dramatically following the discovery

of the carcinogenicity of the mineral asbestos, which

had been banned in most countries by the mid-1980’s

The U.S Occupational Safety and Health Administra-tion (OSHA) recognizes wollastonite dust particles as

an irritant, associated with reduced pulmonary func-tion when inhaled, but not as a carcinogen Addifunc-tion

of wollastonite to products increases their strength and alkalinity, enhancing corrosion resistance The ceramics industry accounts for about 25 to 30 percent of the wollastonite used within the United States The needlelike crystalline structure, LOI, and white coloration are important attributes that wol-lastonite contributes to ceramics It is widely used as filler in ceramics, and in ceramic glazes, frits, and enamels, where it is well known for minimizing shrink-age and crazing Wollastonite is used in the produc-tion of ceramic electrical insulators

Wollastonite is widely used in plastic polymers and elastomers, where it adds structural strength Within the United States, about 35 to 40 percent of wol-lastonite is consumed by the plastics industry It is used in automotive plastics

In metallurgical applications, wollastonite is used

in molds for casting aluminum and continuous cast-ing of steel, where it absorbs impurities Wollastonite

is also used as a welding flux and as a slag conditioner

In the construction industry, high-aspect-ratio wol-lastonite is used in to enhance strength and durability

It is used as filler in portland cement and in the pro-duction of wallboard It is used in roofing materials It

is also used as backing for linoleum Addition of wollastonite to latex paint increases mildew resistance Wollastonite used in paint and coatings is sometimes treated with silane

Wollastonite-containing medical products are able

to act as a substrate for natural bone growth Wol-lastonite-containing ceramics, including Bioglassand Cerabone®AW, can bond with living bone and are in-creasingly used in implants

Applications of wollastonite have been explored for tertiary wastewater treatment and for treating acidified soils A high-pH slurry of water and ground wollastonite applied to environments contaminated

by high levels of acid deposition increases foliage growth and promotes plant germination

Anita Baker-Blocker

Further Reading

Dunn, Peter J Franklin and Sterling Hill, New Jersey: The World’s Most Magnificent Mineral Deposits Peekskill,

N.Y.: Excalibur Mineral Company, 2004

Jeffrey, Kip “Industrial Minerals Development in

Saudi Arabia.” In Industrial Minerals and Extractive

Industry Geology: Based on Papers Presented at the

Com-bined Thirty-sixth Forum on the Geology of Industrial

Minerals and Eleventh Extractive Industry Geology

Con-ference, edited by P W Scott and C M Bristow

Lon-don: Geological Society, 2002

Klein, Cornelius, and Barbara Dutrow Manual of

Min-eral Science 23d ed New York: Wiley, 2007.

Nicholson, John W The Chemistry of Medical and Dental

Materials London: Royal Society of Chemistry,

2002

Philpotts, Anthony, and Jay Ague Principles of Igneous

and Metamorphic Petrology 2d ed New York:

Cam-bridge University Press, 2009

Web Sites

Natural Resources Canada

Canadian Minerals Yearbook, 2005: Wollastonite

http://www.nrcan.gc.ca/smm-mms/busi-indu/cmy-amc/content/2005/66.pdf

U.S Geological Survey

Mineral Information: Wollastonite Statistics and

Information

http://minerals.usgs.gov/minerals/pubs/

commodity/wollastonite/

See also: Agriculture industry; Asbestos; Oxygen;

Sil-icon

Wood and charcoal as fuel resources

Categories: Energy resources; plant and animal

resources

Globally, the amount of wood utilized for fuel exceeds

the total amount of wood utilized for all other purposes.

Between 15 and 80 percent of the total energy needs of

some developing countries are met by wood.

Background

Wood and charcoal are some of the oldest energy

sources: They have provided fuel for human energy

needs since prehistoric times Rough wood and bark

may be burned directly for fuel, or wood may be

con-verted into charcoal by charring in a kiln from which

air has been excluded According to the Food and

Ag-riculture Organization of the United Nations, more

than half of all the wood utilized in the world is used for energy production Wood provides up to 80 per-cent of the total energy needs of some developing countries, but it provides less than 5 percent of the to-tal energy requirement in most developed countries

In some developing areas of the world, fuelwood de-mand is greater than the supply; particularly in parts

of Africa, consumption significantly exceeds replace-ment of the stock of trees

Wood fuel also finds some use in industry, as in the paper industry Industrial uses often burn waste material from other manufacturing processes Bark removed from raw logs, sawdust, planer shavings, sander dust, edges, and trim pieces may all be burned

to generate power while disposing of the unwanted material Small wood particles such as sawdust and shavings may be compressed to produce briquets or

“logs” for use as fuel

Increasing numbers of forests have been planted and cultivated for the sole purpose of energy produc-tion Entire trees are chipped and burned for energy production at the end of a rotation These forests may

be known as forest plantations, tree farms, or energy forests This type of wood production and fuel use has the potential to reduce dependency on fossil fuels Energy forests remove carbon from the atmosphere over their life spans, then release this carbon in vari-ous forms during combustion for energy production

Types of Combustion The direct burning of wood occurs when the surface

is intensively irradiated so that the temperature is raised to the point of spontaneous ignition, anywhere from 260° to more than 480° Celsius, depending on the conditions More common is indirect combus-tion, in which the wood breaks down into gases, va-pors, and mists, which mix with air and burn About 1.3 kilograms of oxygen are required for the complete combustion of 1 kilogram of wood At normal atmo-spheric concentrations, this implies that about 5 kilo-grams of air are needed for the complete combustion

of 1 kilogram of wood During combustion, gases such

as carbon dioxide and carbon monoxide, water vapor, tars, and charcoal are produced, along with a variety

of other hydrocarbons Dry wood or bark and char-coal burn relatively cleanly; wetter wood produces a larger amount of emissions Collectors may be used

to remove particulate matter from industrial sources

It is less feasible to reduce emissions from cooking stoves (either chemically or mechanically), however,

and cooking stoves are a major source of human

ex-posure to emissions from wood burning in much of

the world

Charcoal

Charcoal is lighter than wood and has a higher energy

content It takes approximately 2.5 kilograms of wood

to produce 1 kilogram of charcoal The exact

conver-sion ratio depends on the tree species, the form of

wood utilized, and the kiln technology used Charcoal

is more efficient to transport than wood, and it can be

burned at higher temperatures It is used both for

domestic purposes and, in some countries—Brazil for

example—as an industrial fuel In general, charcoal

is considered a cleaner, less polluting fuel than wood

in that its combustion produces fewer particulates

Charcoal was used extensively as an energy source for

smelting and metalworking from prehistoric times

into the Industrial Revolution, but coal eventually

be-came the principal alternative energy source for these

processes in areas where it was available Today, petro-leum and natural gas are major sources of energy for industrial processes

Energy Content The average recoverable heat energy from 0.5 kilo-gram of wood is about 8,500 British thermal units (Btus) The value ranges from 8,000 to 10,000 Btus per 0.5 kilogram for different species In some effi-cient processes, 12,500 Btus can be recovered from 0.5 kilogram of charcoal If wood with a high moisture content is burned, some of the energy produced by combustion is absorbed as the moisture evaporates, reducing the recoverable energy

Impacts on Environment and Health Traditional uses of wood fuel for cooking and home heating utilize woody material obtained from tree pruning or agroforestry systems These uses are sus-tainable and have relatively little environmental

im-A Filipino family cooks dinner using wood fuel, a common practice, especially in developing countries where other forms of fuel prove too ex-pensive (AFP/Getty Images)

pact in areas with low human population levels, but

they may be associated with serious air pollution

prob-lems as well as widespread deforestation and erosion

if they are the major sources of energy for a large or

concentrated population In most of the areas that

have deforestation problems, the problem is

primar-ily attributable to changes in land use, particularly the

opening of land for agriculture and grazing Fuelwood

is often recovered during such land-use changes, but

the need for fuelwood production is often a

second-ary cause or by-product of deforestation

Industrial power production that utilizes available

technology to ensure high-temperature, virtually

com-plete combustion minimizes hydrocarbon and

partic-ulate emissions and can be designed to meet most

ex-isting air quality standards Less efficient domestic

combustion may be associated with unacceptable levels

of human exposure to airborne particulates, carbon

monoxide, and other hydrocarbons produced by

in-complete combustion The health effects of exposure

to domestic wood fires are difficult to determine, since

it often occurs along with other factors known to

in-crease health risks However, as noted by the nonprofit

organization Environment and Human Health and

other organizations, wood smoke contains

particu-lates as well as recognized carcinogenic compounds

that, depending on the circumstance of exposure,

can pose risks similar to those of cigarette smoke

David D Reed

Further Reading

Argyropoulos, Dimitris S., ed Materials, Chemicals, and

Energy from Forest Biomass Washington, D.C.:

Ameri-can Chemical Society, 2007

Buxton, Richard H How to Convert Wood into Charcoal

and Electricity Bradley, Ill.: Lindsay, 2003.

Food and Agriculture Organization of the United

Na-tions FAO Yearbook: Forest Products Rome: Author,

2008

_ Forests and Energy: Key Issues Rome: Author,

2008

_ State of the World’s Forests, 2009 Rome:

Au-thor, 2009

Leach, Gerald, and Robin Mearns Beyond the Woodfuel

Crisis: People, Land, and Trees in Africa London:

Earthscan, 1988

Pasztor, Janos, and Lars Kristoferson “Biomass

En-ergy.” In The Energy-Environment Connection, edited

by Jack M Hollander Washington, D.C.: Island

Press, 1992

Röser, Dominik, et al., eds Sustainable Use of Forest Bio-mass for Energy: A Synthesis with Focus on the Baltic and Nordic Region Dordrecht, the Netherlands:

Springer, 2008

Solomon, Barry D., and Valerie A Luzadis, eds Renew-able Energy from Forest Resources in the United States.

New York: Routledge, 2009

State of the World’s Forests, 2009 Rome: Food and

Agri-culture Organization of the United Nations, 2009

Web Sites Forest Products Laboratory, U.S Forest Service

Wood Biomass for Energy http://www.fpl.fs.fed.us/documnts/techline/wood-biomass-for-energy.pdf

United Nations, Food and Agriculture Organization

Definition: Wood Energy http://www.fao.org/forestry/14011/en See also: Deforestation; Developing countries; En-ergy economics; Erosion and erosion control; Refor-estation; Renewable and nonrenewable resources; Sustainable development; Wood and timber

Wood and timber

Category: Plant and animal resources

No other material has all the advantages of wood One material may equal wood in insulating quality but lack its abundance and low cost Another may rival it

in strength but fail on the point of workability A third may rank with it in workability but fail to measure up

in durability If wood were a newly discovered mate-rial, its properties would startle the world.

Background Since the human race first started to build crude shel-ters at the dawn of civilization, wood has been avail-able as a construction material Wood has long been used in the construction of buildings, bridges, and boats As technology developed, wood also found a va-riety of less readily recognizable forms, such as paper, films, and pulp products, many of which are mainstays

of daily life