составить краткий пересказ текста
Energy for the future By term f. Dailite
Is there really an energy crisis? Or do we depend too much on a sin­gle form of energy? During recent generations, the world depended mostly on hydroelectric power. Governments built dams across rivers, forming large lakes and putting thousands of acres of land under water. The water flowing over the dams turned turbines to generate electricity. Today giant power lines carry electricity to distant cities. Some scien­tists say that these power lines are dangerous because of the electromag­netic fields they produce. More and more people object to hydroelectric power because it seriously changes the balance of nature.

Thermonuclear power, or nuclear power, comes from the splitting of atoms. It is a widely used and inexpensive form of energy. However, it is possibly the most dangerous because there are health risks from radiation.

Coal, one type of fossil fuel, is one of the dirtiest kinds of energy used. It heats homes and runs factories. Other fossil fuels that come from the earth are petroleum products: gasoline, which is used for most vehi­cles, and natural gas, which is used for some vehicles, but mostly for heating and cooking. At the present time, some New York City buses run on natural gas, which is cleaner and cheaper than regular gasoline.

Alcohol is quite commonly used as fuel in Brazil. It comes from one of Brazil’s main crops, sugar cane, which is easily processed into alco­hol. Methane gas, another source of fuel, comes from garbage, but it is not widely used. From under the ground, Iceland gets geothermal en­ergy, which provides most of the country’s heat and hot water. Other sources of energy include the wind and the sun. In Hawaii, for example, the strong winds in some locations turn giant propellers to produce elec­tricity. In many parts of the world the sun fulfills many energy needs. Solar panels heated by the sun produce electricity. Solar energy already provides many homes with heat and hot water.

What about future sources of energy? Ralph Hansen, a NASA engi­neer and the author of Sun Power, proposed a plan to use solar powered satellites to capture the power of the sun in space, where the sun shines 24 hours a day, 365 days a year. His plan would provide low-cost, non­polluting energy' for the entire world. An additional energy source to be developed is fusion energy, the process that powers the sun and the tars.

Nuclear fusion, or fusion, represents an unlimited source of energy, in fusion, nuclei combine to form bigger nuclei while releasing energy. Not much is known about how to make it usabie, but it seems promising, and millions of dollars of government money will help develop it. Although these sources of energy seem easily available, their high cost is a problem. They are expensive to develop. As a result, they are not as widely used as cheaper forms of fuel.

Energy is needed to warm us, cool us, light our way, cany us from one place to another, and process our food. If the world population in­creases as expected, resources for the kinds of energy we use today may be insufficient. We will have to look closer at different energy sources, such as fusion and solar power. W'hen will we decide to spend the money necessary to develop these energy sources? Who w'ill pay for it? These questions will need to be answered before we can meet our grow­ing energy needs.

zalinairina9    1   03.06.2020 21:29    5