| The energetical potential of solar energy is great, | | | | because it's connected with alienation of big |
| by nowadays calculations it's approximately | | | | territories for transformation of them into |
| 1,57*10^18 Watt peak a year. The science that | | | | reservoirs. Hydroelectric power stations break the |
| studies the methods of collecting and | | | | ecological aqua systems, more over they are |
| transformation of solar energy to another kinds | | | | quite often begin to silt and become ineffective in |
| of energy is solar energetic. | | | | some 50-100 years. In the dry areas evaporation |
| There are several priorities of transformation and | | | | from the surface of water reservoirs is dozen |
| usage of solar energy. The first one is | | | | times higher than evaporation from the surface |
| transformation of solar energy into heat and using | | | | of the land. |
| of it for heating buildings, air conditioning, heating | | | | Nuclear energetics has been seen recently is one |
| or distillation of water. | | | | of the most promising trends in the electricity |
| The basis of such generators of heat energy is | | | | production that united cheap energy produced |
| plane solar collector that allows transforming solar | | | | (one pound of radioactive fuel substitutes two |
| energy to the energy of heat with a temperature | | | | million tons of coal) and a small influence on the |
| of 160-180 F. It looks like a metallic frame with | | | | environment. But the tragedy that happened on |
| special pipes or it's a plane box-like device that let | | | | the power plant in Chernobyl, Ukraine proved that |
| pass the air, water or special liquids. This collector | | | | nuclear energy has a high potential risk. |
| is put into heat isolation cover, with the exception | | | | The exploitation of solar energy can be useful in |
| of it's working part that is subjected to the | | | | many ways. First by substituting the fuel that is |
| sunrays. A 9 ft. sqr. collector gives up to 20 | | | | used on heat power stations it reduces the air |
| gallons of hot water (150-170 F) per day. This | | | | and environment pollution, it reduces the usage of |
| solar water heats have a lot of perspectives to | | | | oil and other fuel that can be used in more |
| be used in remote desert areas or in the areas | | | | important purposes, by substituting nuclear fuel it |
| with a big number of sunny days. The prime cost | | | | reduces the radiation threat, and at the same |
| of the hot water produced by the solar heaters is | | | | time solar energy generators can make us more |
| much lower than one produced by electric boiler | | | | secure, by reducing the dependence upon |
| or gas boiler. It doesn't require any fuel and | | | | uninterrupted fuel supply. |
| doesn't pollute the environment. So the | | | | But still there are many obstacles that prevent |
| advantages of using solar water heaters are | | | | mass spreading of solar energy usage. One of the |
| obvious. | | | | most obvious is low intensiveness of solar |
| The second priority of using solar energy is | | | | radiation even in the sunny weather. Another |
| transformation of it into electricity. If to cover a | | | | obstacle is high initial price of solar energy |
| silicon crystal with a thin, pure for light layer of | | | | generators. |
| metal, than the photons stream, while passing | | | | The primary value for making a plane collector |
| through a metal layer, will release free electrons | | | | solar heater is 1000$ per 1 Watt peak. First |
| from the crystal of silicon. Those electrons will | | | | looking, it may seem that because of the high |
| start to concentrate in the metal layer. This will | | | | price solar energy generators are not competitive |
| cause a potential difference between crystal and | | | | with traditional electric power plants, where this |
| a metal layer. If to connect thousands of such | | | | index is low as 100$ per 1Watt peak. Even small |
| crystals in series or in parallel (to increase voltage | | | | diesel generators are not so costly. But if to |
| and current), we'll get a solar battery that | | | | include the fuel price to the coast of each kilowatt |
| produces direct current. | | | | than this comparison won't be so striking. Even it's |
| Also there exists another trend of using solar | | | | thought that solar generators are cheaper in the |
| energy for electricity production, which is similar | | | | technical exploitation and lifetime is longer than |
| to the heat power plant. It assumes using of glass | | | | that of tradition sources of electric energy. The |
| pipes cover by the semiconductor layer from | | | | calculations show that the price of the electric |
| inside. Such pipe will let pass the sunrays but still | | | | energy produced by solar generators can be |
| collects 80% of them. Sunrays are collected into | | | | reduced in future to .05-.01$ per kilowatt, and for |
| a narrow beam of light with a help of conversion | | | | solar water heater approximately to .02$ per |
| lens. Then this heat is transmitted to the pipe that | | | | kilowatt. |
| is inside of the glass pipe and it heats the working | | | | To be more specific in costs of solar electric |
| pipe up to 1000 F, which is more than enough to | | | | systems lets refer to International Energy |
| melt metallic natrium, that melt near 197 F. | | | | Agency data: "The type of system defines the |
| Incandescent heat conductor is transmitting to the | | | | components you need for a solar system and |
| underground reservoirs, where the heat collected | | | | therefore the costs. The overall system prices |
| for the solar energy makes salt to melt. The heat | | | | for grid-connected systems vary between 7.8 |
| energy form the salt is transmitted to water | | | | and 24.0 USD/Watt peak. The price range for |
| pipes, where the water boils and then the energy | | | | solar systems not connected to the grid is 5.5 to |
| of water steam is used as a moving energy for | | | | 25.2 USD/Watt peak." But still there even more |
| electric current generators. | | | | disadvantages of solar electric systems. First one |
| The transformation of solar energy into another | | | | is that they can be used locally, because the |
| types of energy doesn't bring any visible pollution | | | | direct current produced by solar systems is |
| to the environment, which makes it very | | | | effective for transmission on long distances (not |
| beneficial. Other ways of electricity production are | | | | more than 70 miles). In addition if to refer to |
| tightly connected with the pollution of | | | | MySolar; information on solar energy and solar |
| environment. 80-85 percent of energy used by | | | | systems says: |
| man is got by burning fuel (oil, gas, different kinds | | | | "A solar electricity system causes little extra risk |
| of bio resources). Even so that thee portion of | | | | for lightning when normal precautions (earthing, or |
| heat power plants is decreasing now, still lots of | | | | lightning protection at places that a prone to |
| countries use it as a primary source for getting | | | | lighting such as high towers etc) are taken. |
| energy (75% power plants in China and nearly | | | | Lightning can cause damage to equipment such as |
| 40% of power plants in Russia use oil, coal and | | | | inverters and batteries" (available on web: |
| gas). Heat power plants produces 50% of | | | | Even despite all the disadvantages of solar |
| carbonic gas, 35% sulphur and nitrogen oxides | | | | systems, this kind of alternative source of electric |
| released into atmosphere and nearly the same | | | | energy is spreading all over the world. The leading |
| amount of dust. Recent researches also show | | | | place in production of electricity by solar systems |
| that heat power plants twice more pollute the | | | | is taken by the USA (40% of world's production) |
| environment with radiation contamination than do | | | | with total power 450 megawatts and with a total |
| nuclear power plants. | | | | square of solar heat collectors in 100 million sqr ft. |
| The influence of the hydroelectric power stations | | | | And the development of this power industry will |
| on the environment is also a subject of concern, | | | | be rapid in next decades. |