ENERGY SOURCES, ENERGY CHOICES

What are the best energy sources? «Best» depends on many factors-how the energy is being used, where it is being used, what energy sources are available, which sources are most convenient and reliable, which are easiest to use, what each costs, and the effects on public safety, health, and the environment. Making smart energy choices means understanding resources and their relative costs and benefits.

Some energy sources have advantages for specific uses or locations. For example, fuels from petroleum are well suited for transportation because they pack a lot of energy in a small space and are easily transported and stored. Solar photovoltaics are well suited for heating or electricity generation in desert climates or other sunny places with lots of flat, open space. Small hydroelectric installations are a good solution for supplying power or mechanical energy close to where it is used. Coal is widely used for power generation in many fast-developing countries-including China, India, and many others-because domestic supplies are readily available.

Efficiency is an important factor in energy costs. How efficiently can the energy be produced, delivered, and used? How much energy value is lost in that process, and how much ends up being transformed into useful work? Industries that produce or use energy continually look for ways to improve efficiency, since this is a key to making their products more competitive.

The ideal energy source-cheap, plentiful, and pollution-free-may prove unattainable in our lifetime, but that is the ultimate goal. The energy industry is continuing to improve its technologies and practices, to produce and use energy more efficiently and cleanly. A future source may be hydrogen-based.

Energy resources are often categorized as renewable or nonrenewable.

Renewable energy resources are those that can be replenished quickly-examples are solar power, biomass, geothermal, hydroelectric, wind power, and fast-reaction nuclear power. Renewable energy sources supply about seven percent of energy needs in the United States; the other 93 percent comes from nonrenewables. The two largest categories of renewable energy now in use in the U.S. are biomass-primarily wood wastes that are used by the forest products industry to generate electricity and heat-and hydroelectricity.

In most cases, fossil energy resources are currently more affordable and easier to store and transport than renewable sources. For renewables to become more widely used, many hurdles must be overcome-most related to producing and distributing renewable energy more economically.

How far into the future will energy resources be available to supply our needs? The sustainability of any particular energy resource is an important consideration in determining where to invest in energy technology and infrastructure. All energy resources, whether renewable or nonrenewable, must be used efficiently and sustainably in order to safeguard the future for ourselves and our children.

Nonrenewable energy resources include coal, oil, natural gas, and uranium-235, which is used to fuel slow-reaction nuclear power. Projections of how long a nonrenewable energy resource will last depend on many changeable factors. These include the growth rate of consumption, and estimates of how much of the remaining resources can be economically recovered. New exploration and production technologies often increase the ability of producers to locate and recover resources. World reserves of fossil energy are projected to last for many more decades-and, in the case of coal, for centuries. 

Вариант IV

1. Перепишите и переведите предложения. Подчеркните в них Participle I и Participle II и установите их функции в предложении – определение, обстоятельство или часть глагола-сказуе-мого (см. образец выполнения № 1).

1. The USA in the world^’s leading producer of cooper.

2. Early in 1941 Henry Ford was granted government contracts.

3. One can use several modern devices while detecting and measuring radioactivity.

4. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material.

5. Approximately 30% of incoming solar radiation (insolation) is reflected back to space while the rest is absorbed by clouds, oceans and land masses.

6. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, cyclones and anti-cyclones.

7. While bombarding the upper layers of the atmosphere, cosmic rays reach the surface of the earth.

2. Перепишите и переведите предложения. Подчеркните в них модальные глаголы или их эквиваленты (см. образец выполнения № 2).

1. A computer in to solve complicated problems many millions of times faster than a mathematician.

2. To measure the vast distances between different planets scientist had to use special instruments.

3. He can speak English fluently.

4. He has to work much before he is able to complete his research.

5. Heat can be divided into three different types.

6. A great number of plastics should find their applications in the electrical industry.

7. He had to work hard before he was able to submit his paper to a scientific journal.

8. Solar photovoltaic installations may be ground-mounted or built into the roof or walls of a building.

3. Перепишите и письменно переведите на русский язык следующие предложения. Определите видовременную форму и залог сказуемого (см. образец выполнения № 3).

1. Fossil fuels were created by the decomposition of primitive organisms.

2. Deposits of coal, oil and gas are now found below ground in many areas of the world.

3. Cars have been designed that burn gasoline more cleanly and efficiently, with better filtering mechanisms.  

4. This material is unaffected by solar radiation.

5. There are many properties that man has found useful in his application of electromagnetic waves.

6. The flow of electrons in one direction results in an electric current.

7. The energy sources of the world are decreasing while the energy needs of the world are increasing.

8. The isotopes of the element hydrogen were given individual names.

9. Electronics is usually thought of as that part of electricity which deals with vacuum tubes and transistors.

10. The behaviour of metals is greatly affected by the changes in temperature.

4. Перепишите предложения и переведите их на русский язык, обращая внимание на разные значения глаголов to be, to have, to do (см. образец выполнения № 4) .

1. Fossil fuels are sources of energy that humans have taken advantage of over thousands of years.

2. Hydrogen, a simple, abundant element, has very high energy potential.

3. Many specialists do not believe that hydrogen is the fuel of the future.

4. The exam was to start in the afternoon.

5. He is still doing his ordinary everyday job for the company.

6. Did the company guarantee the delivery of each lot without delay?

7. You are to live here for the next six months.

8. You do not have to be a computer programmer to use a computer.

9. Scientists had to create new materials for industry.

5. Перепишите и переведите следующие предложения, обращая внимание на неличные формы глагола (см. образец выполнения № 5).

1. Fossil fuels – including coal, oil, and natural gas – are the most important energy sources at present.

2. Fossil fuels were created by the decomposition of primitive organisms, buried in sand and mud, and compressed under the weight of accumulating layers.

3. To control these emissions, today`s coal-fired power plants are equipped with scrubbers, filters, and other devices

4. Planting more trees in one way to remove more carbon dioxide from the atmosphere.

5. Einstein didn’t enjoy talking very much; in fact, he waited till he was three before he started to talk.

6. Opening her eyes, the baby began to cry.

7. The book published last week is his first book written for children.

8. Some of the first communications satellites were designed to operate in a passive mode.

6. Перепишите и переведите следующие предложения, обращая внимание на перевод зависимого и независимого причастных оборотов (см. образец выполнения № 6).

1. The computer`s electronic memory recording all the operator`s commands, the picture of deviations was produced.

2. A curve showing the behavior of metal is given in Fig. 21.

3. Automakers also are developing fuel cells extracting hydrogen from gasoline or methanol.

4. The teacher having asked many questions, a friend of mine had to spend much time to answer them.

5. The information mentioned above is very interesting.

6. Having finished this work he started to solve another problem.