Home Random Page



Hydroelectric Power

For many centuries, humans have used falling water as an energy source to mill flour, saw logs, 20 and power numerous machines. Today, hydroelectric facilities employ falling water to produce electricity. To generate hydroelectric power, a high-volume river is dammed to create enough vertical incline for falling water to automaticallypower the generators.

Hydroelectric power is widely available; since 1983, nearly one-third of all new electricity-generating plants built in the United States have been hydroelectric installations. Furthermore, if 25 every sizable river in the United States were dammed for this purpose, hydroelectric power could supply 50 percent of our total electricity needs. Global hydroelectric development lags even

Essential Academic Vocabulary

further behind; only 6 percent of the worlds hydroelectric potential is being used, and in South America and Africa, where its potential is greatest, only 1 percent has been developed. At the other extreme, hydroelectric power is integralto Canada's economy, with 75 percent of its

30 electricity coming from this clean resource.

Although hydroelectric power is nonpolluting, some persistentenvironmental problems are associated with its use. Dams can disrupt the local ecological balance by altering or destroying wildlife habitat. They may also block natural erosionprocesses—their reservoirs eventuallyfill with sediment that would otherwise replenish coastal beaches. Decisions to build dams must,

35 therefore, balance the environmental costs against the energy yield.

Tidal Power

In coastal areas with a high tidal range—the fluctuationsin the water surface level between high and low tide—energy from rising and falling water levels can be produced by building a dam across a narrow bay or inlet. The dam's gates are then opened during rising tides and closed to

40 restrainthe water at its maximum height. During successivelow tides, the elevated water is channeled seaward to electrical generators, producing renewable, pollution-free energy.

Tidal power production, however, requires a minimumtidal range of 8 meters (26 feet), and it disturbs the ecology of surrounding coastal habitats. As yet, no tidal-power facilities in North America have been constructed, although there are a coupleof strong candidates for future

45 development. Maximum development of the United States' potential tidal power would provide only 1 percent of the nation's total electrical needs, although it could become a significant supplementto other energy sources in some areas. Worldwide potential for this energy source, only slightly better, is about 2 percent of the total electricity demand.

Solar Energy

50 Solar-powered pocket calculators and wristwatches take advantage of an energy source that is a paradigmof a totally renewable and easily accessible energy source that requires no expensive drilling or destructive strip mining, cannot be monopolized by unfriendly political regimes, and produces no hazardous wastes or air pollution.

Solar heating can be either passiveor active. Passive solar heating distributes the heat

55 naturally; in northern regions, the simplest way to heat spaces passively is to construct buildings with windows facing south. Sunlight passes through the window glass and heats objects within the room; heat radiates from these objects to warm the air. Such an architectural design, coupled with efficient insulation, complementstraditional heating systems by sharply reducing both air pollution and the cost of heating with fossil fuels.

60 Active solar heating works via water-filled, roof-mounted panelswith black linings that

absorb maximum sunlight. The solar-heated water is circulated throughout the building for space heating or directly to the building's hot water system. Solar panels are most productive in mild, sunny climates such as Florida, Texas, California, and the Southwest, where they can provide as much as 90 percent of a building's heating needs.

65 Wind Power

Wind power is another clean, renewable, nonpolluting energy source whose use for pumping groundwater and powering sawmills and flour mills can be tracedback over centuries in the Netherlands, where windmills are intrinsic to the rural landscape. Wind power, however, is rarely cost-effective because winds need to blow constantly, forcefully, and from a uniformdirection 70 for large-scale production.

Chapter 16 • Environmental Science 163


Fuels derived from plants and animals are known collectively as biomass fuels. In developing countries, as much as 35 percent of the energy used for cooking and heating comes from burning two common biomass fuels: wood and animal dung. Biomass fuels also include grain alcohol (an

-5 additive to gasoline for vehicleuse), methane gas releasedfrom the decaying garbage in landfills, combustible urban trash, and plant waste from crops such as sugarcane, peanuts, and corn. The predominantbiomass fuel is wood, which heats about 10 percent of contemporaryNorth American homes, more than are heated by electricity from nuclearpower plants.

The advantages of biomass fuel, however, may be offsetby environmental concerns. Unlike

so most other renewable resources, biomass fuels can create air pollution and desertification

problems when used on a wide scale or implemented poorly. As with oil and coal, burning of this resource introduces poisonous gases and particles into the air, reducing air quality and increasing global warming. Moreover, in arid regions, a common sequenceof events produces a scenarioof environmental destruction. An overreliance on cutting down trees for energy leads to the removal

85 of root systems that help retain water and soil, therebycontributing to desertification, which consequently eliminatesanimals that provide dung for fuel.

There is considerable controversyover the best ways to utilize alternative energy sources. Federal subsidiesfor alternative energy have been minimizedin recent years, and little support from government ministrieshas been forthcoming. Nonetheless,it is crucialto implement

90 comprehensiveand coherent initiativesto offset energy shortages in the future.

Adapted from Stanley Chernicoff, Haydn A. "Chip" Fox, and Lawrence H, Tanner, Earth: Geologic Principles and History (Boston: Houghton Mifflin, 2002), 360-63.

1. Vocabulary in Context

Choose the best meaning according to the context in which the word is used in the reading.


a. inevitably(line 1) eventually primarily unavoidably
b. adjacent(line 8) near isolated overseas
c. convert(line 9) sustain transform devise
d. inclined(line 14) unifying likely sloping
e. confined(line 16) extracted exhibited limited
f. integral(line 29) visible incompatible important
g- persistent(line 31) dynamic ongoing virtual
h. fluctuations(line 37) changes capacities intervals
i. supplement(line 47) display presumption addition
J- paradigm(line 51) style model notion

Essential Academic Vocabulary


k. uniform(line 69) constant alternative flexible
1. predominant(line 77) marginal principal neutral
m. eliminates(line 86) allocates incorporates removes
n. forthcoming(line 89) given modifiable fundamental
o. comprehensive(line 90) ambiguous ideological complete

2. Reading Comprehension

Getting the Facts

1. In paragraph 1, what two reasons are given for governments and companies to seek alternative energy sources?

a. _______________________________________________________________________

b. _______________________________________________________________________

2. Six types of alternative energy sources are described in the reading. Complete the following chart to show the characteristics of each source.

Energy Source Advantages Disadvantages Environmental Damage







Chapter 16 • Environmental Science

3. Indicate whether the following statements about the information in the reading selection are true (T) or false (F).

__ Geothermal heat was discovered in Iceland in 1904.

__ _ Africa has developed only 1 percent of hydroelectric potential.

— In South America, 75 percent of electricity comes from hydroelectric power.

__ Worldwide potential for tidal power is estimated to be only 1 percent.

__ Solar power can provide 90 percent of home heating needs in sunny climates in

the United States.

__ Windmills have been used for centuries in the Netherlands.

__ Ten percent of homes worldwide use wood for heat.

__ Biomass fuels consist primarily of methane gas and garbage.

__ Desertification can occur when too many trees are cut down in dry areas.

__ Grain alcohol can be added to gasoline used to fuel cars.

d Making Inferences

1. According to the information provided in the reading and your own general knowledge, list the alternative energy sources in order of widespread use in the United States {a being the most widespread,/ being the least widespread). Be prepared to support your order with evidence from the text, either directly stated or inferred.

biomass hydroelectric power tidal power

geothermal energy solar energy wind power


b. c. d.



2. Why do you think there is controversy over alternative energy sources? Why doesn't the U.S. government provide more financial support for the development of these technologies?

True word knowl­edge and under­standing comes from using words in meaningful situ­ations and activi­ties that require conscious thought and effort.

Essential Academic Vocabulary

3. Dictionary Skills

Study the dictionary entries for inclination, incline, and inclined. Then use a synonym or a short phrase to replace each of the bold words in the following sentences.

in*cli*na#tiotl(In'kta na'shsn) n. 1. [C; U] A natural tendency to act in a certain way: Many people have an inclination to sleep late on weekends. 2. [U] A slant or slope: the steep incli­nation of the roof.

in*cline (In kiln') v. in»clined, in»clin#ing, in»clines.intr. 1. To slant or slope: a road that inclines steeply. 2. To lower the head or body, as in a nod or bow: The baby's head inclined on his chest. tr. 1. To cause (sthg.) to lean, slant, or slope: We inclined the boards against the side of the building. 2. To cause (sthg.) to bend or bow: The conductor inclined his head as a sig­nal for us to get ready to play. n. (m'klln')- A surface that slants; a slope: The car skidded down the icy incline of the street. ♦ be inclined to.To be likely: You might be inclined to change your mind after you read this.

in*clined (In kllnd')adj. 1.Sloping, slanting, or leaning: a ramp inclined at 15 degrees. 2. Tending or likely: a man inclined to act too quickly.

1. 2. 3. 4. 5. 6. 7.8. 9. 10.

Some people are inclinedto change their minds about environmental issues after reading scientific reports.

In order to generate hydroelectric power, a river must have a dam with a large vertical incline.

When the old man fell asleep, his head inclinedon his chest.

Mike inclinedhis head to acknowledge that he had seen me.

My sister is inclinedto be impatient with people who are passive.

My inclinationis to keep worldng on a project without a break until I am finished.

I am inclinedto trust the experts in this case.

Behind my house is a wooded inclinewhere I cut firewood to heat my house.

Although the new energy project is controversial, neither side has shown any inclinationto discuss it together.

I am not mathematically inclined,so I tend to avoid courses that involve math.

Chapter 16 • Environmental Science

4. Word Forms

3 Chart Completion

Complete the following chart with the different forms of each word. Note that some words do not have all forms.


Noun Verb Adjective Adverb ]
supplement supplement suppJeMed'tarif X
  complement   X


subsidy   X X
  X   inevitably
initiative, initiation      
  uniform uniform  





Word Forms in Sentences

Use the correct form of the word to complete the following sentences. Make sure the word you choose fits meaningfully and grammatically into the sentence.

1. supplement Tidal power rnnlH he a SUpp/&M&flt(irif energy sonrce in rnasfal areas.

2. complement Wood is often used to___________ conventional heating systems in

North American homes.

Problems from erosion_________

3. persistent 4. subsidy 5. inevitably 6. coherent 7. initiative 8. uniform

_________ in the environment for decades.

The development of alternative energy was___________ by the

government in the past.

There will be____________ shortages of fossil fuels in the future.

written, so it was

The environmental report was not_________

difficult to understand.

Communities can with fossil fuels. There is little____ region.

alternative energy projects to compete

_________ in plans for alternative energy systems for this

9. automatically Electricity can be generated by____________ processes.

Essential Academic Vocabulary


10. eventually Dry areas can


11. predominant The_______

become deserts if too many trees are cut

of fossil fuel usage in this area has greatly increased air


5. Collocations

The following adjectives are commonly found with specific verbs and adverbs.


Verbs Adverbs Adjectives i
be, seem, become remarkably, perfectly, reasonably, very coherent
remain, prove, be, consider something, see something as absolutely, really, clearly, obviously crucial
be, be situated, lie, stand, be located directly, immediately adjacent
be extremely, fully, totally, truly, co'- prehensive

quite, fairly

immediately, readily, unusually, not very





completely, fully, totally, almost, virtually




appear, be, look, seem, become

absolutely, probably, apparently, virtually, politically



be, prove, become, remain

extremely, highly, somewhat, politically, rather


■dCombine the words from the chart (verb + adverb + adjective) to create meaningful sentences on the topic of alternative energy.

■I The n&w proposal for ihe installation of wind power seems remarkabli^ coherent.



Chapter 16 • Environmental Science





The following common collocations have specific meanings. Discuss these meanings with a partner or your teacher. Write five meaningful sentences that include some of these collocations.

controversial figure religious conversion

passive restraints passive smoking passive vocabulary

on automatic pilot school uniform

temperature fluctuations vehicular homicide worst-case scenario

1 ____ When ) commute to work in mij vehicle, )'m on automatic pilot and hardly notice

the, journey._________________________________________________________






Essential Academic Vocabulary

6. Word Parts

aqua-, -hydr- (water)

Each of the following words contains the Latin word part aqua- or the Greek word part -hydr-. Both word parts mean "water." In each word notice the word part that gives a clue about the word meaning and the suffix that indicates the part of speech. Match the words with their meanings.

aquaculture aquarium aquatic aqueduct aquifer

dehydrate hydroelectricity hydrophobia hydroplane hydrotherapy

1. ____________ fear of water

2. ____________ remove all the water from food or the body

3. ____________ the treatment of disease using water

4. ____________ the business of raising fish to sell as food

5. ____________ electricity produced by water

6. ____________ a structure like a bridge that carries water over a river or valley

7. ____________ living or growing in water

8. ____________ water under the surface of the earth

9. ____________ a plane that can take off from and land on water

10. ____________ a glass container or building that houses fish and water animals

7. Writing

ua Paraphrasing

See Appendix III for additional information on paraphrasing.

Rewrite the following sentences in your own words. You can use synonyms, change the grammar structure, and/or change the order of ideas. However, the overall meaning of the sentence should remain the same.

1. As the reserves of fossil fuels decrease and environmental damage related to their use inevitably increases, governments and industries are seeking alternative ways to anticipate the populations' growing energy needs.

In order to minimise, environmental problems and to compensate for the future

depletion of oil and coal reserves, countries are looking at alternative energy__________

sources to meet the needs of their people.______________________________________

Chapter 16 • Environmental Science

2. Maximum development of the United States' potential tidal power would provide only 1 percent of the nations total electrical needs, although it could become a significant supplement to other energy sources in some areas.

3. Solar power is a paradigm of a totally renewable and easily accessible energy source that requires no expensive drilling or destructive strip mining, cannot be monopolized by unfriendly political regimes, and produces no hazardous wastes or air pollution.

4. Wind power is another clean, renewable, nonpolluting energy source whose use for pumping groundwater and powering sawmills and flour mills can be traced back over centuries in the Netherlands, where windmills are intrinsic to the rural landscape.

5. The predominant biomass fuel is wood, which heats about 10 percent of contemporary North American homes, more than are heated by electricity from nuclear power plants.

6. Unlike most other renewable resources, biomass fuels can create air pollution and desertification problems when used on a wide scale or implemented poorly.

Paragraph Writing

Write a response to oneof the following topics. Include at least six to eight vocabulary words

in your paragraph.

1. On Assignment: Last semester you took a course on alternative energy and found out from your professor about a volunteer project in Nepal, where you could help rural people build simple, solar-powered stoves for cooking, thereby helping to preserve the land from deforestation. You were immediately interested in this project, signed up, and now find yourself in a remote village in the mountains, far from the comforts of life you are used to.

Essential Academic Vocabulary

Write a short letter to a friend describing the village environment, the energy sources used previously by the villagers, and how your solar project will help them.

Dear___________ ,

Here.) am in a small village, in Nepal

2. Alternative Energy: Write a paragraph explaining which alternative power source would be best to use in the region where you live. What features of the climate or the geography of the area make it the best choice? Do you know of any current use of this power source in your region? What advantages and disadvantages would there be to this power source?

8. Speaking

Cooperative Learning Research Project

Decide on a specific alternative energy source that all group members wish to learn more about. Each member of the group should search for an interesting article on the Internet about a specific topic related to this energy source. Possible topics for the specific alternative energy source include the following: locations, technology, cost of construction, government subsidies, construction methods, infrastructure, environmental problems, and controversies. Each group member is responsible for reading an article several times and taking notes on the main ideas and

supporting details.

Using only brief notes, each group member should give a brief oral summary about the

content of the article to the group. Group members should ask questions and discuss issues raised

in each article.

Finally, as a group, prepare a short oral summary of the information collected from all the

articles to present to the whole class.

Chapter 16 • Environmental Science

Date: 2015-12-11; view: 1322

<== previous page | next page ==>
LIE DETECTION TESTS | Partner Discussion: Planning an Energy-Efficient House
doclecture.net - lectures - 2014-2024 year. Copyright infringement or personal data (0.018 sec.)