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