Introduction. For thousands of years, man has used natural resources: from firewood and coals burned for cooking and heat generation, to nuclear power. But, unfortunately, the resources are not infinite, and their use is quite large compared to the renewal process. New technologies of solar panels and windmills have become one of the most effective directions in the search for alternative energy sources.
People have relatively recently found ways to collect and convert solar energy, but nevertheless they have been exploiting it for many years, the same applies to wind energy. "In houses facing south, the winter sun penetrates through the gallery, and in summer the path of the sun passes over our head and directly over the roof, which forms a shadow" - this is how Socrates described the use by the Greeks of the dependence of solar paths on the time of year in their architecture after the energy crisis associated with a shortage of wood coal due to deforestation.
Also, from our ancestors on the territory of Tajikistan there were houses called “Chorkhona”, in the center of the ceiling of which there was a window special in that it used sunlight for lighting and for warming the house, it was designed so that regardless of the position of the sun, it fulfilled its task.

Fig.1. Tajik "Chorkhona"
Indeed, with the total surface area of our planet amounting to 510.1 million km2, the calculation of the photon flux turns out to be 325 watts per 1 m2 or 165.7 trillion kW per hour, that is, in 24 hours so much energy is generated that power plants will not be able to produce even within a year.
Setting a goal. Tajikistan, which is located at the source of the water, and its high mountains have been covered with snow for centuries, and in these mountains there is the largest glacier on earth. Despite the fact that our homeland is rich in springs, the farthest village suffers from a lack of water, and in winter there is a limit of electricity. Although we have hydroelectric power plants and new ones are being built, but if the winter is cold and the water level drops, then we will face a shortage of electricity not only in remote villages, but also in cities. In order to overcome the electricity limit and achieve a bright future, we need to develop “green” energy. In this regard, we have several suggestions, which we will give below:
 Start actively using the technology of agrivoltaics and flotovoltaics.
 Start to produce insulation of houses with solar thermal technologies.
 Start the production of goods using the technology of solar fabrics.
 Start using the available technologies of solar windows, Hantiles roofing tiles, exterior wall cladding panels.
Start using solar trackers in SES to increase energy production.
Start devoting more time to the development of existing technologies and contribute to the development of new ones.
 Completely abandon environmentally harmful and dangerous methods of electricity production.

Reflecting on the future of humanity and the planet, it is safe to say that thanks to technology it will change a lot. Using green energy, it is possible to prevent some problems of humanity, such as the lack of clean drinking water, insufficient energy supply to settlements. Thanks to solar stations in hot regions of the world, where there is an abundance of sun, it is possible to obtain a large amount of energy, and in northern countries with the help of wind farms. It is also possible to increase the amount of drinking water, since GES are most often built on fresh water bodies, namely lakes and rivers. This means that by replacing some of the GES with SES and VES, there will be less industrial water unsuitable for consumption. Solar and wind energy belong to renewable resources, that is, their number is unlimited. In turn, traditional types, such as oil, gas, uranium and others, not only consume their reserves, but also cause great harm to the environment. As previously mentioned, with the help of green energy, it is possible to solve some of the problems of humanity, besides, thanks to it, it is possible to improve the ecology of the planet. Wind and solar energy can help with the planet's climate change, which is becoming increasingly destructive. Although hydropower is environmentally friendly and renewable, it harms aquatic life, among which there may be endangered species, as well as some types of hydropower change the bottom of the reservoir and the habitat of some aquatic inhabitants. GES installed on the seas can lead to a change in the water level in coastal waters, as well as such installations affect the salinity of the water. In addition, GES require quite large areas, while VES, despite their size, occupy only a small part of the territory. As for atomic energy, this energy obtained from radioactive elements is not only exhaustible but also particularly dangerous, although the power produced is quite large. One mistake can lead to a tragic outcome of a vast, and possibly global, scale and the death of a large number of living beings. It follows that some types of energy production can harm the environment, the biosphere and the planet as a whole. Wind and Solar energy have no emissions of harmful substances inherent in nuclear power plants, and greenhouse gases that are emitted during the use of oil and coal, do not pollute the environment and do not affect the living conditions of animals, as well as their habitat, which means they are environmentally harmless.

"Electrical phenomena arising from the illumination of bodies", describing the occurrence of voltage or electric current in substances under the influence of light, the French physicist Becquerel prompted scientists to think about the use of solar energy. The discovery of the photoconductivity of selenium in 1873 by the English electrical engineer Smith and the external photoelectric effect in 1887 by the German physicist Hertz also made an invaluable contribution [1].
For more than half a century, scientists have been searching for a direct converter of light into electricity, and eventually in 1950 they managed to create the first full-fledged solar panel.
There are 3 methods of light energy conversion widely used around the world: solar collectors, solar reactors and solar panels [1].

 Solar collectors
The principle of operation of collectors is to heat water by the Sun. Until recently, such installations were more often used in hot countries for hot water supply, but modern collectors are designed for use in northern regions as well.
 Solar reactors
The initial goal of the reactors was to produce hydrogen without harming the environment. Hydrogen is a fairly environmentally friendly fuel, the combustion product of which is ordinary water vapor. Over time, an energy complex capable of providing heating, hot water and electricity was developed. In good weather, batteries generate electricity, and excess energy is spent on hydrogen production, and if there is a lack of generated electricity, accumulated hydrogen reserves are used.
 Solar panels
The method of direct conversion of solar energy into electrical energy is constantly being improved and expanded, the rapid growth of the introduction of SES is confirmed by statistics.
In addition to large energy projects, solar panels are increasingly used in various fields: they are installed on roofs of houses, on lighting poles, embedded in portable chargers, computer equipment, etc.

Fig.2. Solar panels.
One of our achievements in the field of solar energy is a light receiving panel consisting of cells that are made up of a two-layer semiconductor material that has photoconductivity properties. The upper layer of the semiconductor material has a negative potential, and the lower layer has a positive potential. When the sun's rays hit the top layer of the semiconductor material, an external photoelectric effect occurs, in other words, a semiconductor with a negative potential begins to give off electrons, and a semiconductor with a positive potential captures electrons. Therefore, based on this, it is possible to close the circuit, connect the load to the layers and the electrons that leave the layer with a negative potential will rush through the load to the layer with a positive potential, after which they return back to the layer with a negative potential [1].
Modules are made of different materials and in search of the most effective material, research was conducted and as a result it was found that multilayer solar cells of the GaAs/ Ge/ GaInP type show a photovoltaic conversion coefficient of 32%, in practice it turned out to achieve greater efficiency.
The conversion of all radiation spectra into electricity is one of the most promising directions, which is the reason for the development in this direction by many scientific centers, companies, institutes and the results are already there.
Nowadays, the material of the converter of solar radiation into electric current based on a rectifying antenna is most popular among manufacturers as an alternative to silicon, which is obvious at its much cheaper cost. But it is worth noting that it contains toxic lead, which it would be nice to replace and it was replaced in the form of tin. During the tests, it was noticed that electrons with increased energy, the so-called "hot electrons", gave it away not after a few hundred femtoseconds, as in the case of lead, but after a few nanoseconds, which is much longer. In the case of conventional panels, electrons are converted into heat, and in our case, using the slowness of electrons, it is possible to convert them into electricity. Professor M. Loi predicts the efficiency of such batteries with a value of 66%. Scientists are busy investigating the causes of such slow electron scattering and how to achieve slower scattering [1].

Researchers from Israel proposed to convert sunlight into ideal radiation in order to solve the problem with the absorption of light elements of the entire radiation spectrum, and a special photoluminescent material was developed for this task. The material converts the entire spectrum of radiation into light, which is absorbed by the panel. Conversion to electricity due to light conversion increases up to 50% [1].
The Chinese, as the largest suppliers of solar panels, also contributed and offered their panel working, and at night, in which the phosphor layer plays a special role. In the daytime, the phosphor delays the light that has not been absorbed by the photocell, and at night it transmits energy to the photocells by glowing. Despite the low efficiency of 25% at night, the development is able to increase the efficiency of solar energy.
At the Solar Power International 2017 conference, Hanergy presented its wave-shaped roof tiles with built-in Hantiles photocells. This roofing tile does not spoil the aesthetics and comes out cheaper than the roof and panels separately. And the Swiss CSEM Center has proposed exterior wall cladding panels, which are also solar and have high heat and sound insulation properties, having a monotonous appearance [1].
The power generating windows developed by the Los Alamos National Laboratory are not externally different from ordinary windows. In the development of which a single-chamber double-glazed window is used, in which quantum dots are embedded, the basis of which is manganese on the outer glass and indium copper selenide on the inner. These glasses absorb light and redirect it to the frame, where it is converted into electricity using built-in solar cells [1].
It is believed that the best place to install solar panels are the deserts of our planet, because there is a lot of light there, and there are practically no clouds, but the problem is that generating panels do not like too high temperatures that are characteristic of deserts. They are most effective at temperatures below 25 ° C, a temperate climate is great for their location, but areas with such a climatic condition are not so easy to find and agrivoltaics acts as a win-win solution. You just need to install panels over agricultural fields, thereby solving the problem, both with the necessary areas and with the subsequent cooling of the panels, the cause of which will be the evaporation of water by plants.
Researchers from the University of Arizona found that such panels from May to June are 3% more effective than conventional ones. Despite the seemingly insignificant increase, in large quantities of its implementation, you can get a decent increase. They are actively trying to extend this concept to reservoirs, in the case of reservoirs it is called “flotovoltaics". Placing the panels on the water surface is effective because the evaporating water cools the batteries, thereby increasing their productivity [2].
One of the most obvious solutions to how to get the most out of solar panels is the constant rotation of the batteries towards the energy source, because if the rays fall directly on the batteries, their efficiency increases. For this reason, in fact, the panels are installed in a position in which the light from the solar panels falls on the batteries for a greater amount of time. The sun tends to change its position in the sky not only depending on the time of day, but also during the year, from which it is concluded that the above method is not ideal.
For this reason, photovoltaic trackers were invented, which, although they take from 5 to 10% of the generated energy, but still the costs are easily covered by the additional generation of generated energy, which in some areas allows you to increase the amount of energy received by 45%. In particular, these trackers perform better in high latitudes, where the Sun moves along the horizon more than near the equator. In the field, their use is more than justified, and due to the weighted structure, installation on the roofs of houses is not particularly practical [2].
Due to the catchy appearance of most solar panels, it becomes impossible to integrate them organically into the urban environment, and the reason for everything is silicon, which they are mainly produced by and it looks very heavy. Silicon perfectly copes with its task, but not only it can perform this function. Scientists are trying to find an alternative to it, which can be embedded in glass. It's enough to imagine a picture of a beautiful landscape and you admiring it, and next to the window lies your smartphone, which is charged from the window, isn't it great? But to make this a reality, we need to find a material that will be lighter than silicon and will also have a transparent property. The solution is solar cells made of organic compounds. Dyes and polymers serve as the basis and can be applied to the glass inserted into the window. It may seem contradictory that the substance that is supposed to absorb light needs to be opaque, but in the case of organic solar panels, they can be made from materials that will transmit visible light and take infrared. Of the elements that we have, 43% of the radiation passes in the area, which is more suitable for office high-rises and will also act as a tinting, and for residential buildings it will be a little dark. The plus will also be that such batteries are much cheaper to produce than flint ones, they are also light, which will allow us to equip mobile devices and cars with such batteries. However, compared to silicon batteries, they are less efficient, such batteries convert only 13% against 18-22% of silicon. Another advantage will be the fact that they can be used anywhere and previously unpromising for electricity generation surfaces [2].
In the future, the extraction of electricity will be possible not only for static objects stuffed with batteries, there are already some successes in this regard. Fabrics are being created in the fibers of which solar panels are integrated, the purpose of this development is that a person can simply, walking in the sun, generate a current that can be used to power the device. We managed to create a prototype consisting of 200 ultra-small elements measuring 3 by 1.5 millimeters, which is comparable to the size of a flea that could recharge a Fitbit wristwatch. It does not generate a huge amount of electricity, but 2000 such elements are enough to charge a smartphone. These elements also managed to be integrated into heavy textiles by the type of tents, which are designed for a long stay in the sun [2].
Unlike previous technologies, solar thermal energy
sets itself the task of obtaining thermal energy for heating the house. Rechargeable batteries are being developed, which are filled with “solar thermal fuel". It is a substance that absorbs energy and, if necessary, is able to release it. The rays of the sun, destroying its chemical bonds, force its molecules to rearrange, thereby acquiring a new more heat-intensive configuration. We already have fuel that can store energy for two decades. The physical filter acting as a catalyst returns the molecules to their previous state, thereby releasing them. Around the device in just a couple of minutes it turned out to raise the temperature by 63 °. With proper development of this technology, it is doomed to be in demand. Before the onset of winter, the user needs to put a device on the roof of the house that will bask in the sunlight, and upon the onset of winter, you just need to click the switch and it gets warm inside the house and you don't need to spend any gas and electricity to heat the house, as well as concern for the environment, because there are no harmful emissions. And this process can be repeated again and again [2].
A little bit about Wind power
Wind power is based on the use of high-performance wind turbines. A low-power installation is interesting as autonomous energy sources for individual houses or groups of houses. To use large wind turbines, a sufficiently strong and stable wind is required, which is not typical for all regions, such turbines are used in Western countries, the USA and China.
All modern powerful wind turbines are almost identical in terms of design, the basis of which is a horizontal rotor with an impeller. Due to the high area of resistance to the wind flow created by large blades, their number is three.
The installations have a sufficiently large mass, for example, the Enercon E-126 has a mass of 6000 tons, with such a mass, a strong, steady wind is required for the operation of the installation.
The units are equipped with electric motors for starting rotation. Many models are installed in the prevailing wind direction, but some have guidance devices. They are usually placed in desert or steppe regions, in shelf and coastal areas in which there are constant and even winds. The components of the design of wind generators include [3].
 Support tower or mast
The masts have a conical shape, which contributes to good stability and uniform load distribution. Masts are made on site: they are successively poured with concrete into suitable formwork. At the base of the masts there is a platform made of concrete, which is the basis of the foundation, which ensures the immobility and stability of the structure.

 Gondola

Inside the gondola there is a compartment with a generator and rotation transmission devices. The rotor is also attached to it, which is a continuation of the gondola and forms a streamlined shape with it. The outer part of the rotor consists of a hub and blades. The hub is a central fairing mounted on the generator shaft and used to attach the blades. The gondola has the ability to rotate around the tower to be installed in the wind, for which an asynchronous electric motor and a gear train encircling the entire upper part of the tower are used. The possibility of rotation is not available for all models, for offshore wind turbines operating on flows of two opposite directions, this function is optional.
 Turbine generator
The generator is a ring-type device. The turbine rotor is structurally integrated with the generator rotor, this reduces losses and reduces material consumption. For such structures, it is fundamentally important to exclude the rotation transmission nodes as much as possible, instead using single integral elements.

Fig. 3. Wind turbine.
The blades are made of special fiber with steel inserts. Depending on the size of the blades, they are made whole or made up of parts, and there may also be design changes, additions or other features. As a rule, three blades are installed, since rotors with two blades experience heavy loads at the moment when the blades are vertical, and the installation of more than three blades creates additional air resistance. The device of the blades provides for the possibility of changing the profile or angle of rotation, allowing you to adjust the aerodynamics in accordance with the wind flow mode.
Generators used in industry have impressive dimensions and high power, for example, the Enercon E-126 with a height of 198 m and a blade span of 128 m, with an area of 12668 m2.
The size of the windmill corresponds to the power generated by it. There are larger or smaller models, but they have a lot of weight and size, but even with this, the area on the ground is occupied only by the base of the tower, the remaining can be used for agriculture.
It should be noted that powerful generators are uneconomical individually. Most often they are part of large stations, numbering dozens or even hundreds of individual installations, occupying quite large areas and producing a total capacity of several MW, provided optimal wind conditions ensure equal load and stable performance. Although the parameters of powerful wind turbines depend on their power, the design of all models is almost the same. Therefore, only the proportions of the device's impeller and the power generated by the installations can be compared.
The work of several hundred operating wind turbines has the ability to create large capacities. Wind power plants have provided a solution to the problem of supplying electricity to areas without the possibility of building hydroelectric power plants or nuclear power plants. It is noteworthy that both the lack of opportunities and bans on the construction of nuclear power plants have become the reasons for the appearance of many wind farms. In addition, wind power is recognized as environmentally friendly, which has played a significant role in the development of this industry.
Therefore, in the absence of alternative options or in the presence of the necessary conditions for the high-quality and uniform operation of wind turbines, the wind farm becomes an acceptable way of obtaining energy.
Conclusion. Having fulfilled the set goals, we will achieve a bright ecological future in which there will be no environmentally harmful and dangerous sources of electricity. It will be possible to avoid repeating the history that happened with the Chernobyl nuclear power plant. We will also get rid of a number of problems that cause garbage harmful to the ecology of our planet. In the end, we will be able to avoid a number of serious problems that may arise if we continue to neglect the ecological state of our planet.
In Tajikistan, hydroelectric power plants are actively used and this method of extracting electricity is very terrible for us, because we have to sacrifice drinking water for the operation of these stations. Tajikistan is rich in its water resources, which must be used competently, and spending drinking water to generate electricity against the background of a shortage of drinking water in some countries of the world looks inappropriate. Of the total runoff, more than 80% is potable, 9.88 thousand m3/person per person. It is much better to make mutually beneficial deals, we export our water and import useful resources for us. Being a sunny country, an excellent option for us is the extraction of electricity by building a SES. The construction of SES in certain areas will simplify the laying of electrical wires.

List of sources used
1. New technologies in solar panels (qwizz.ru )
2. What will solar energy look like in the future? (poznavaemoe.ru )
3. High-power industrial wind turbines: how wind farms are arranged, profitability and design features (energo.house)