Solar Energy

1. Solar energy has proved to be an ideal source of power. Man had learned to obtain electric power directly from the sun. In a climate where continuous sunshine can be guaranteed for long periods of the year architects have designed and built houses to be heated by solar radiation. The solar collector built into the roof consists of a number of blackened metal plates with spaces between them. Air is circulated between the plates and when heated, it passes through a large container filled with gravel¹. During the day the gravel heats up, and at night cold air is passed through the hot gravel and then to the rooms where warmth is required. A surprising feature of such a system is that under suitable conditions solar radiation can greatly raise the temperature of the air.

2. The simple principle of focusing the sun’s rays by mirrors has been applied to create a very-high-temperature furnace for melting metal alloys. To obtain a really high temperature for such furnaces by traditional methods is not easy. There is a limit of the temperature that can be achieved by combustion of fuels. Solar installations have no such limitations. Furnaces of this type are now under construction in many countries.

3. The device employed for converting solar energy into useful power is the solar cell. This is somewhat like thermocouple² which consists of two dissimilar metals joined together. In the solar cell the junction is of two different kinds of semiconductors and the cell is energized not by heat but by light. The basic semiconductor employed in the solar cell is silicon in the form of a single crystal.

4. We know the solar energy to be produced by fusion³ of hydrogen atoms into helium atoms. The reaction that takes place in the sun is made possible due to extremely high temperatures – millions of degrees. Now the highest temperature commonly reached on earth can be measured in thousands of degrees. An electric arc, for instance, has the temperature of about 3000⁰C. There are good prospects that this reaction of fusion can be reproduces artificially and in a controlled way on earth. If we had succeeded in⁴ doing it we should have found a complete solution to energy problems, for we have a vast store of hydrogen in the oceans, enough to satisfy the world’s power requirements for thousands, it not millions of years.

Notes

¹gravel - гравий

²thermocouple - термопара

³fusion - синтез

⁴to succeed in - удаваться что-либо сделать

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VII. Рекомендації щодо безпечного проведення ремонту та технічного огляду сільськогосподарської техніки	\|

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