Encyclopedia of Global Resources part 101 pptx

See Gasoline andother petroleum fuels Petroleum refining and processing Category: Obtaining and using resources Petroleum is separated into a variety of fuels—gaso-line, kerosene, and d

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Petroleum fuels See Gasoline and

other petroleum fuels

Petroleum refining and processing

Category: Obtaining and using resources

Petroleum is separated into a variety of

fuels—gaso-line, kerosene, and diesel fuel—and into feedstocks for

the chemical industry Petroleum is first distilled, then

each of the “cuts” is further treated or blended to

pro-vide the various marketed products A significant

ef-fort is devoted to gasoline production, in order to

ob-tain the quantities needed and the desired engine

performance.

Background

Petroleum, or crude oil, is found in many parts of the

world It is not a chemically pure substance of

uni-form properties Rather, petroleum is a complex

mix-ture of hundreds of individual chemical compounds

that occur in various proportions, depending on the

source and geological history of the particular

sam-ple As a result, various kinds of petroleum range in

properties and appearance from lightly colored,

free-flowing liquids to black, tarry, odiferous materials It

would be impractical to design furnaces or engines

ca-pable of efficient, reliable operation on a fuel whose

characteristics varied so widely Therefore, to provide

products of predictable quality to the users,

petro-leum is separated into specific products that, through

treating, blending, and purification, go on the market

as the familiar gasoline, kerosene, and diesel and

heating oils Some petroleum supplies also contain

impurities, most notably sulfur compounds, that must

be removed for environmental reasons The sequence

of separation, blending, treating, and purification

operations all make up the processes of petroleum

refining

Distillation

The first major step in refining petroleum is

distilla-tion, the separation of components based on boiling

point In principle, it would be possible to separate

pe-troleum into each of its component compounds, one

by one, producing many hundreds of individual pure

compounds Doing so would be so laborious that the

products would be too expensive for widespread use

as fuels or synthetic chemicals Instead, petroleum is separated into boiling ranges, or “cuts,” such that even though a particular distillation cut will still be composed of a large number of compounds, its physi-cal properties and combustion behavior will be rea-sonably constant and predictable

Many crude oils contain dissolved gases, such as propane and butane These are driven off during dis-tillation and can be captured for sale as liquefied pe-troleum gas (LPG) The first distillation cut (that is, the one with the lowest boiling temperature) that is a liquid is gasoline Products obtained in higher boiling ranges include, in order of increasing boiling range, naphtha, kerosene, diesel oil, and some heating oils

or furnace oils Some fraction of the crude oil will not distill; this is the residuum, usually informally called the resid The resid can be treated to separate lubri-cating oils and waxes If the amount of resid is large, it can be distilled further at reduced pressure (vacuum distillation) to increase the yield of the products with higher boiling ranges and a so-called vacuum resid Catalytic Cracking

The product that usually dominates refinery produc-tion is gasoline Gasoline produced directly by distilla-tion, called straight-run gasoline, is not sufficient in quantity or in engine performance to meet modern market demand Substantial effort is devoted to en-hancing the yield and quality of gasoline The yield of straight-run gasoline from very good quality petro-leum is not more than 20 percent; from poorer quality crudes, it may be less than 10 percent About 50 per-cent of a barrel of petroleum needs to be converted to gasoline to satisfy current needs Gasoline engine per-formance is measured by octane number, which indi-cates the tendency of the gasoline to “knock” (to deto-nate prematurely in the engine cylinder) Knocking causes poor engine efficiency and can lead to me-chanical problems Most regular grade gasolines have octane numbers of 87; straight-run gasolines may have octane numbers below 50

Increasing the yield of gasoline requires producing more molecules that boil in the gasoline range Gen-erally the boiling range of molecules relates to their size; reducing the boiling range is effected by reduc-ing their size, or “crackreduc-ing” the molecules Octane number is determined by molecular shape The com-mon components of most crude oils are the paraffins,

or normal alkanes, characterized by straight chains of

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carbon atoms These paraffins have very low octane

numbers; heptane, for example, has an octane

num-ber of 0 A related family of compounds, isoparaffins,

have chains of carbon atoms with one or more side

branches; these have very high octane numbers The

compound familiarly referred to as iso-octane

(2,2,4-trimethylpentane) has an octane number of 100

In-creasing the yield and engine performance of

gas-oline requires both cracking and rearranging the

molecular structures

Both of these processes can be performed in a

sin-gle step, using catalysts such as zeolites For this

rea-son, the overall process is known as catalytic cracking

The feedstock to a catalytic cracking unit is a

high-boiling cut material of low value Different refineries

may choose to use different feeds, but a typical choice would be a vacuum gas oil, which is produced in the vacuum distillation step Much effort has gone into the development of catalysts and into evaluating ap-propriate choices of temperature, pressure, and reac-tion time Catalytic cracking is second only to distilla-tion in importance in most refineries It can produce gasolines with octane numbers above 90 and in-creases the yield of gasoline in a refinery to about 45 percent

Catalytic Reforming Straight-run gasoline and naphthas have acceptable boiling ranges but suffer in octane number Treating these streams does not require cracking, only altering

Separation and Uses of Petroleum

CRUDE OIL IN

P E T R O L E U M R E F I N E R Y

FUEL OIL

DE-WAXING

LUBRICANTS AND GREASES

DIESEL OILS

FUEL OIL

GASOLINE

BOTTLED GAS

CRACKING ROOFING

PAINTS

PLASTICS PHOTOGRAPHIC FILM SYNTHETIC RUBBER WEED-KILLERS AND FERTILIZERS

MEDICINES DETERGENTS ENAMEL SYNTHETIC FIBERS

CANDLES

WAXED PAPER POLISH

OINTMENTS AND CREAMS

JET FUEL SOLVENTS INSECTICIDES

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the shapes of molecules—re-forming them—to

en-hance octane number This process also relies on

lysts, though of different types than those used in

cata-lytic cracking Reforming catalysts usually include a

metal, such as nickel or platinum Catalytic reforming

can produce gasolines with octane numbers close to

100

Hydrotreating

Other distillation cuts, such as kerosene and diesel

fuel, require less refining Two processes of

impor-tance for environmental reasons are the removal of

sulfur and removal of aromatic compounds Since

both involve the use of hydrogen, they are referred to

as hydrotreating

Sulfur removal—hydrodesulfurization—is done to

reduce the amount of sulfur oxide emissions that

would have been produced when the fuel is burned

Additionally, sulfur compounds are corrosive and can

have noxious odors Hydrodesulfurization is

per-formed by treating the feedstock, such as kerosene,

with hydrogen using catalysts containing cobalt or

nickel and molybdenum As environmental

regula-tions become more stringent, hydrodesulfurization

will become increasingly important

Aromatic compounds also have several

undesir-able characteristics Some compounds, such as

ben-zene, are carcinogens Larger aromatic molecules,

which might be found in kerosene or diesel oil,

con-tribute to the formation of smoke and soot when

these fuels are burned Soot formation is unpleasant

in its own right, but in addition, some soot

compo-nents are also carcinogens Aromatic compounds are

reacted with hydrogen to form new compounds—

naphthenes or cycloalkanes—of more desirable

prop-erties

Resid Treating

Resids can be treated with solvents to extract

lubricat-ing oils (these oils can also be made durlubricat-ing the

vac-uum distillation of resid), waxes, and asphalts

Al-though lubricating oils are produced only in low yield

(about 2 percent of a barrel of crude may wind up as

lubricating oil), they are commercially valuable

prod-ucts Asphalts are of great importance for road

pav-ing Resid is also converted by heating into petroleum

coke, a solid material high in carbon content

High-quality petroleum cokes are used to manufacture

syn-thetic graphite, which has a range of uses, the most

important of which is for electrodes for the

metallur-gical industry Poorer quality petroleum cokes can be used as solid fuels

Petrochemicals Petroleum is the source not only of liquid fuels but also of most synthetic chemicals and polymers Some products having low value as fuels, such as naphtha or even waxes, can be decomposed to produce ethylene, the most important feedstock for the chemical indus-try Ethylene is converted to polyethylene, polyvinyl chloride, polyvinyl acetate, and polystyrene, which to-gether make up a large share of the total market for plastics Another petroleum product of great use in the chemical industry is propylene, the starting mate-rial for making polypropylene and polyacrylonitrile

Harold H Schobert

Further Reading

Berger, Bill D., and Kenneth E Anderson Modern Pe-troleum: A Basic Primer of the Industry 3d ed Tulsa,

Okla.: PennWell Books, 1992

Gary, James H., Glenn E Handwerk, and Mark J

Kai-ser Petroleum Refining: Technology and Economics 5th

ed Boca Raton, Fla.: CRC Press, 2007

Jones, D S J Elements of Petroleum Processing

Chich-ester, England: John Wiley & Sons, 1995

Leffler, William L Petroleum Refining in Nontechnical Language 4th ed Tulsa, Okla.: PennWell, 2008 Meyers, Robert A., ed Handbook of Petroleum Refining Processes 3d ed New York: McGraw-Hill, 2004 Royal Dutch/Shell Group of Companies, comp The Petroleum Handbook 6th ed New York: Elsevier,

1983

Speight, James G The Chemistry and Technology of Petro-leum 4th ed Boca Raton, Fla.: CRC Press/Taylor &

Francis, 2007

Szmant, H Harry Organic Building Blocks of the Chemi-cal Industry New York: Wiley, 1989.

Web Site U.S Department of Energy, Energy Information Administration Refining

http://www.eia.doe.gov/pub/oil_gas/petroleum/ analysis_publications/oil_market_basics/

refining_text.htm See also: Gasoline and other petroleum fuels; Oil and natural gas chemistry; Oil industry; Petrochemi-cal products; Propane

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Category: Mineral and other nonliving resources

Where Found

Phosphate rock ore is mined in Florida and North

Carolina (more than 85 percent of U.S output), as

well as Idaho and Utah Major world producers in-clude China, followed by the United States, Morocco and the western Sahara, Russia, Tunisia, and Brazil Primary Uses

Phosphate rock is used primarily in the production of fertilizers In the United States, more than 95 percent

is used in the manufacture of phosphoric acids, which

Data from the U.S Geological Survey, U.S Government Printing Office, 2009.

28,000,000 11,000,000

600,000 2,400,000 3,700,000 800,000

7,800,000

30,900,000 10,800,000

Metric Tons

60,000,000 50,000,000

40,000,000 30,000,000

20,000,000 10,000,000

United States

Syria

South Africa

Senegal

Russia

Morocco and

western Sahara

Togo

Tunisia

Other countries

2,300,000 6,000,000 800,000

50,000,000

3,000,000 3,100,000 5,500,000

Egypt

China

Canada

Brazil

Australia

Israel

Jordan

Phosphate Rock: World Mine Production, 2008

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in turn are used to make ammonium phosphate

fertil-izers and feed supplements for animals

Technical Definition

Phosphate rock is a general term for any earth

mate-rial from which phosphorus can be extracted at a

profit The principal phosphorus-bearing mineral in

these deposits is a hydrated calcium phosphate called

apatite, Ca5(PO4)3(OH) Apatite can also

accommo-date variable amounts of fluorine (F) and carbonate

ion (CO3) and contains from 18.0 to 18.7 percent

phosphorus

Description, Distribution, and Forms

In its organic form, apatite occurs as the main

compo-nent of bones and teeth, and it makes up the shells of

some marine invertebrates Some phosphate

depos-its, particularly those in Florida, also contain certain

aluminum phosphate minerals Commercial

phos-phate deposits occur in two major forms: (1) marine

sedimentary deposits, in which phosphate-rich beds

are associated with carbonate rocks (limestones,

dolostones) and mudstones or shales deposited on

the floor of an ocean or shallow sea, and (2) igneous

deposits, in which apatite has crystallized from

for-merly molten plutons (molten magma that solidifies

below ground)

The sedimentary deposits are by far the most

im-portant phosphate producers In the United States

these areas are located in the eastern states of Florida,

Tennessee, and North Carolina, and the western

states (the “western field”) of Wyoming, Montana,

Idaho, Utah, and Nevada The most widespread,

con-tinuous deposits of phosphate rock in the United

States occur in the Phosphoria formation of Utah,

Wy-oming, Idaho, Montana, and Nevada

By far the most important phosphate localities

worldwide are in North Africa and Russia Elsewhere

in the world, significant deposits are found in North

Africa, specifically Algeria, Tunisia, Morocco, and

Egypt The principal igneous deposits occur in Russia

(the Kola Peninsula) and in Ontario, Canada

History

Production started in the United States in 1867, with

mining of the extensive Florida deposits beginning

in 1888 Over time, the price of phosphate rock

jumped—with a notable spike in 2007—as

agricul-tural demand increased worldwide The mining of

phosphate rock has also spiked in China, as that

na-tion’s development escalates Interest in the produc-tion of phosphate has prompted exploraproduc-tion of new resources, particularly sources off the coasts of Mex-ico and Namibia

Obtaining Phosphate Phosphate rock is the ore of the element phosphorus (P) It occurs mostly as marine (saltwater) sedimen-tary deposits in which the predominant phosphorus-bearing mineral is apatite, a hydrated calcium phos-phate Phosphate rock is mined from sedimentary marine phosphorites both on land and on continen-tal shelves and seamounts and is available via a process

in which sea organisms die and settle to the bottom of

a given water body Through mining, inorganic phos-phates are obtained and can be separated from other chemicals

Uses of Phosphate Most of the mined phosphate rock is turned into wet-process phosphoric acid, which is used for fertilizers and supplements in animal feed It is also used in many industrial processes, including the manufac-ture of phosphoric acids and other chemicals used in the fields of metallurgy, photography, and medicine and in sugar refining, soft drinks, preserved foods, ce-ramics, textiles, matches, and both military and com-mercial pyrotechnics (munitions and fireworks)

John L Berkley

Web Site Florida Institute of Phosphate Research http://www.fipr.state.fl.us/index.html See also: Eutrophication; Fertilizers; Mohs hardness scale; Phosphorus cycle; Sedimentary processes, rocks, and mineral deposits

Phosphorus cycle

Category: Geological processes and formations

Phosphorus stimulates rapid growth of algae in water and is the main cause of eutrophication Fertilizers, de-tergents, and animal waste are major sources of phos-phorus.

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The phosphorus cycle describes the continuous

move-ment of organic and inorganic phosphorus from the

Earth’s crust and living organisms to water bodies and

the atmosphere

Overview

The element phosphorus (abbreviated P) exists

pri-marily in its highest oxidized state—that is, the

phos-phate ion (PO4) Phosphorus can be found in a variety

of inorganic and organic compounds Geochemical

phosphorus occurs mainly as calcium phosphate

(apa-tite), Ca3(PO4)2, and as hydroxyapatite, Ca5(PO4)3(OH), and is relatively insoluble Even when phosphorus is leached into solution through weathering, it readily reacts with other elements to form calcium, alumi-num, manganese, and iron phosphates or binds to clay minerals, resulting in other insoluble phases Phosphorus has no stable gaseous compounds There-fore, phosphorus is transported mainly in particulate form by means of overland and riverine runoff and to

a lesser extent by atmospheric precipitation

Phosphorus is essential to all life processes Along with carbon and nitrogen, phosphorus is a highly

Assimilation

by plant cells

Weathering of rock Incorporation into sedimentary

rock; geologic uplift moves this

rock into terrestrial environments

Phosphates

in solution

Loss in drainage

Phosphates

in soil

Decomposition by

fungi and bacteria Urine

Animal tissues and feces

Plant tissues

The Phosphorus Cycle

The biogeochemical phosphorus cycle is the movement of the essential element phosphorus through the earth’s ecosystems Released largely from eroding rocks, as well as from dead plant and animal tissues by decomposers such as bacteria and fungi, phosphorus migrates into the soil, where it is picked up by plant cells and is assimilated into plant tissues The plant tissues are then eaten by animals and released back into the soil via urination, defecation, and decomposition of dead animals In marine and freshwater aquatic environments, phosphorus is a large component of shells, from which it sediments back into rock and can return to the land environment as a result of seismic uplift.

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portant nutrient of freshwater bodies Carbon and

ni-trogen are more readily available than phosphorus,

and the short supply of phosphorus can control the

growth of aquatic vegetation and other

microorgan-isms Thus, phosphorus can act as a limiting factor

An abundance of phosphorus can lead to excessive

growth of filamentous algae, a condition called

eutro-phication, which can create odor and taste problems

and can cause biofouling of the filters, pipes, and

in-strumentation that are crucial parts of water supply

systems

Much phosphorus input is anthropogenic—in

other words, human activities contribute to

phospho-rus input at a much greater rate than natural

pro-cesses do Human waste and detergents in domestic

and industrial sewage, along with leaching and runoff

of fertilizers and animal waste from agricultural lands,

are the major sources of phosphorus

Inorganic phosphorus is taken up by living cells

and becomes a major constituent of nucleic acids,

phospholipids, and different phosphorylated

com-pounds In nature, organic phosphorus is derived

from dead and living cells through excretion and

de-composition respectively

Generally, both inorganic and organic phosphates

are transformed into dissolved inorganic

orthophos-phate The orthophosphate either precipitates or is

consumed or released by phytoplankton or bacteria

Through these lower forms of life, phosphorus is

first assimilated by zooplankton and subsequently by

higher order organisms Precipitated phosphorus is

utilized by aquatic plants and is diffused into the

am-bient water or is buried in deep sediments In

eutro-phic (nutrient-rich, particularly phosphorus-rich)

lakes the amount of phosphorus precipitated from

the atmosphere is relatively insignificant in

compari-son to the amount present in water and sediments

On the other hand, atmospheric phosphorus may be

a significant source of phosphorus for oligotrophic

(oxygen-rich) lakes

In stratified lakes during the spring season under

well-mixed oxidized conditions phosphorus may bond

to the bottom sediments However, in winter, under

anoxic (oxygen-deficient) conditions, phosphorus is

released from the sediments into the water column

Therefore, phosphorus-laden sediments can serve

as internal sources of phosphorus and can continue

to promote eutrophication long after the external

sources have ceased to exist

Panagiotis D Scarlatos

See also: Agriculture industry; Clean Water Act; Envi-ronmental engineering; Eutrophication; Fertilizers; Food chain; Lakes; Phosphate; Soil; Water pollution and water pollution control

Photovoltaic cells

Categories: Energy resources; obtaining and using resources

Photovoltaic cells convert the abundant, free, and clean energy of the Sun directly into electricity Already widely used in satellites, many consumer products, and residential or commercial electrical systems throughout the world, photovoltaic technology is one of the most promising alternative, renewable energy re-sources.

Background Since ancient times, people have used energy from the Sun In the seventh century b.c.e., mirrors and glass were used to concentrate heat to light fires Solar energy can also be converted into electricity Photo-voltaic (PV) cells, also called solar cells, convert sun-light directly into electricity at the atomic level through the process called photovoltaics

A PV cell is made of a special semiconductor mate-rial, so that when photons, or small light particles, strike the cell, some of them are absorbed within the photoelectric material The energy of the absorbed light loosens electrons (negatively charged compo-nents of an atom) and causes them to flow freely, pro-ducing an electric current

French physicist Alexandre-Edmond Becquerel discovered the photovoltaic effect in 1839 He no-ticed that when exposed to light, certain metals or ma-terials produced small quantities of electric current

In 1883, Charles Fritts built the first working solar cell

by coating the semiconductor material selenium with

a thin, almost transparent layer of gold The early so-lar cells had low energy conversion efficiencies, trans-forming less than 1 percent of the absorbed solar en-ergy into electricity

In 1905, Albert Einstein published his theories about the nature of light and the PV effect, which laid the foundation for photovoltaic technology The first silicon photovoltaic cell was developed by Daryl M Chapin, Calvin Fuller, and Gerald Pearson at Bell

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oratories in 1954 With an efficiency of 6 percent, it

was the first solar cell that could convert enough

en-ergy to power ordinary electrical equipment After

sil-icon was adopted for many kinds of electronic

cir-cuitry in the 1960’s, silicon production increased

exponentially, resulting in lower prices Silicon

be-came the standard semiconductor material for PV

cells At first, the crystalline form of silicon was more

common, but the amorphous form eventually

be-came widespread

Applications

The first practical application of photovoltaics

oc-curred in 1958, when the U.S satellite Vanguard 1

used a radio transmitter powered by solar cells

Un-like the battery-powered transmitter on board, which

broadcast for less than one month, the solar battery

sent signals for years This breakthrough

demon-strated the reliability of PV for electric power

genera-tion in space, and solar cells became indispensable in

subsequent satellites In 2000, solar panels were

intro-duced at the International Space Station, which held the largest solar power array in space

During the energy crisis in the 1970’s, interest in

PV technology for applications other than those for space and commerce grew By 1978, the first commer-cial solar-powered calculators and wristwatches were introduced

Stand-alone PV systems have become a major source of energy for remote areas far from conven-tional power lines PV technology provides the neces-sary amount of reliable energy most economically Applications of PV cells include ocean navigational buoys and lighthouses, remote scientific research and weather stations, telecommunications systems such as mountain-top radio transceivers, and emergency call boxes or road signs

In industrialized nations, PV technology is used in grid-connected electrical systems to supplement con-ventional energy generation Centralized PV power stations and PV systems in buildings are the two kinds

of grid-connected installations PV power stations,

This jail in Germany is fueled by the photovoltaic cells installed on the roof (AP/Wide World Photos)

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which send power instantaneously into the grid or

dis-tribution network through transformers and

invert-ers, are especially cost-effective during hours of peak

demand A PV system in a building is a decentralized

system with distributed generation in grid-connected

PV arrays or in solar panels on the roofs of residential,

commercial, or industrial buildings

More than 70 percent of the people in the world do

not have electricity In developing countries and rural

areas that do not have access to conventional

electri-cal supplies, PV technology is playing an increasingly

significant role Domestic PV systems supply the

power for lighting, refrigeration, and basic appliances

in many villages and island communities PV water

pumps are also used worldwide for village water

sup-plies and irrigation

Advantages and Disadvantages

Photovoltaic technology has significant advantages

over conventional and other alternative energy

tech-nologies First, because PV systems make electricity

di-rectly from sunlight without gaseous or liquid fuel

combustion, there is minimal impact on the

environ-ment PV production is clean and quiet, producing no

greenhouse gases or hazardous waste by-products

Ranging from microwatts to megawatts, PV energy is

also flexible and can be used for a wide range of

appli-cations

PV technology is also cost-effective over the life of

the system Sunlight is free and ubiquitous, so PV has a

free, abundant fuel supply PV systems are also

inex-pensive to construct and easy to operate and maintain

for long periods of time, because there are no huge

generators, complicated wiring, transmission lines,

transformers, or moving parts that require frequent

servicing or replacement Because of this high

reli-ability and reli-ability to operate unattended, PV

technol-ogy has been the choice for space satellites and

re-mote areas, where power disruptions and repairs

would be costly Another significant advantage of PV

systems is that they are modular, so the systems can be

configured in a variety of sizes and moved as needed

PV technology is more expensive than producing

electricity from a grid, but it can provide energy

dur-ing peak demand times, such as the hours when air

conditioners are turned on during the summer

Dur-ing these times, a grid-connected PV array can be used

to meet the peak demand, rather than relying on

ex-tremely expensive peaking power plants or other

lim-ited energy resources Thus, PV systems can prevent

power outages such as brownouts and blackouts Solar panels connected to a grid can also produce surplus electricity when the Sun is shining, and this excess is credited against electricity used, resulting in an aver-age 70 to 100 percent savings on electric bills Other limitations include efficiency and perfor-mance Because PV technology depends on sunlight, weather conditions affect output However, even on extremely cloudy days, a PV system can generate up to

80 percent of its maximum output

The Future of Photovoltaics Although sunlight is free, PV hardware manufactur-ing has been too expensive to compete with utilities Hence, PV technology has been most cost-effective in remote or rural areas without conventional sources of electricity, rather than in urban areas with traditional grid power However, as more research is done on less expensive materials, the technology improves, and costs decline, PV has the potential to become the lead-ing alternative energy resource It is estimated that in-stalling PV systems in only 4 percent of the area of the world’s deserts would be enough to supply electricity for the whole world

During the 1990’s, research into other materials in-creased efficiency to more than 10 percent In 1992, the University of South Florida developed a 15.89 per-cent thin-film cell In 1994, the National Renewable Energy Laboratory (NREL) fabricated a solar cell made of gallium indium phosphide and gallium arse-nide, which exceeded 30 percent efficiency In 1999, the NREL and Spectrolab combined three layers of PV materials into a single 32.3 percent efficient solar cell

In the twenty-first century, PV power generation has expanded to meet global energy needs In 2008, the world PV market reached a record high of 5.95 gigawatts, up 110 percent from 2007 The global mar-ket consisted of eighty-one countries Spain, Ger-many, the United States, Italy, and Japan were the top five markets Global revenues for the PV industry to-taled $37.1 billion Thin-film production grew 123 percent to 0.89 gigawatt World solar cell production was 6.85 gigawatts, up from 3.44 gigawatts in the previ-ous year China and Taiwan increased their share of solar-cell production from 35 percent in 2007 to 44 percent in 2008 In 2008, huge multimegawatt PV plants were built in Germany and Portugal In the United States, the growing PV industry helps gener-ate jobs, reduce dependence on foreign oil, and pro-tect the environment

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By 2009, China had made a commitment to

reach-ing 2-gigawatt solar capacity by 2011 and become a

leader in the PV industry, especially in the production

of source parts and components China has

estab-lished installation incentives and built assembly the

plants in the United States The Chinese company

Suntech Power Holdings increased sales in the United

States by reducing prices on its solar panels In 2009,

the American company Evolution Solar Corporation

announced it was moving its physical location to China

to take advantage of opportunities there

Alice Myers

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