How can the efficiency of utilisation of solar energy be improved?

Annually the sun supplies the earth with 6 x l0⁷ kilo­watt hours of radiant energy, more than 20,000 times greater than the world’s total power consumption. But only a very small part of the solar energy which reaches the earth be­comes useful.

One of the most important problems is the discov­ery of ways and means of more effective use of solar radia­tion, the energy of unlimited possibilities.

The sun is the source of all main forms of energy. We must learn to gather and store sunlight and convert its energy into other forms of energy. Today man converts solar energy into electricity with an efficiency of about 10 per cent. This is not much, but not long ago this also seemed impossible.

Systematic work on the utilization of solar energy began in the Soviet Union in 1926. At present there are some centres which deal with solar power problems in our country. They do much work on solar energy utilization, especially in Cen­tral Asia and Armenia. There are some places there where the amount of solar power that hits the ground at noon is nearly equal to the capacity of the famous Dnieper Hydroelectric Station.

There exists a project of solar electric station which will generate 2,500,000 kwh of electricity a year. That is not very much, but the power will be quite cheap. On the order of the day are power stations which will use principles of direct conversion of solar energy into electric one.

The solar energy is the main power supply source for all space systems – spaceships and rockets as the density of solar radiation in space is half as great as on the earth.

The solar energy provides the conditions which are nec­essary for man’s life on the earth. But the man will also make the sun heat and cool his homes, produce fresh water from sea water, melt metals and generate great quantities of electric power.

Notes:

6xl07 – six multiplied by ten to the seventh power

on the order of the day …………. to make the sun heat ……………

на повестке дня заставить солнце согревать

Solar energy

We know that all the energy comes from the sun, with the exception of nuclear energy. Yet we are only now begin­ning to use the sun as a source of energy.

The most primitive device for catching and trapping the heat of the sun is the gardener's greenhouse. This solar water-heater is a coil of pipes placed in a box on the roof of a house, put in black concrete and covered with a glass pane. The wa­ter circulating in the pipes is heated by the sun and then pumped into a hot-water tank from which one can take it.

Various types of “solar houses” are being designed by engineers and architects, especially in America. In these houses, some medium (for example, water, Glauber’s salt or some other) is used to store the heat of the sun and to release it when required.

These efforts at utilizing the heat of the sun show that the engineers realize the great possibilities of solar heating but also its limitations, as a great many countries do not have enough sunshine to make a solar house worth building. Tropical zones, however, have no use for extra heat. In these zones cooking by solar energy is becoming more and more important in everyday life. Solar cookers are being used in­creasingly in India, Sudan and many African countries.

Solar furnaces are still very much in the experimental stage. French scientists are operating them in their research station in the Pyrenees. Russian scientists and engineers built an enormous “helio-boiler”, consisting of a 80-foot tower sourrounded by twenty-three concentric railway tracks. Special huge reflectors move around on these tracks to con­centrate the sun's rays on to the boiler in the tower. This machine produces enough superheated steam for a turbo­generator with 1,000 kw output.

However, scientists believe that the most efficient way of generating electricity from sunlight is by means of "solar batteries". The first solar battery demonstrated in 1954 operated with semiconductor crystals similar to those used in transistors. When sunlight strikes such a crystal, an elec­tric current is generated. Solar as well as atomic batteries are very suitable for supplying power to the transmitters in space rockets and spaceships because of their long life.

In the old days, the stage of civilization reached by a nation was measured in pounds of soap per head a year. Today it is the amount of horsepower of kilowatt-hours available to every person which indicates the degree of civilization of the country.

Notes:

a coil of pipes …………………… to make a solar house worth build- ing……………………………….. the Pyrenees …………………….. helio-boiler ………………………

змеевик зд. чтобы строить солнечный дом (основанный на принципе отопления с помощью солнца) Пиренеи солнечный котел