In recent years, scientists are particularly interested in alternative energy sources. Oil and gas will end sooner or later, so we have to think about how we will survive in this situation right now. In Europe, windmills are actively used, someone is trying to extract energy from the ocean, and we will talk about solar energy. After all, the star that we see almost every day in the sky can help us save non-renewable resources and improve the ecological situation. The value of the sun for the Earth can hardly be overestimated - it gives heat, light and allows all living things to function on the planet. So why not find him another use?
A bit of history
In the mid-19th century, physicist Alexander Edmond Becquerel discovered the photovoltaic effect. And by the end of the century, Charles Fritts created the first device capable of converting solar energy into electricity. For this, selenium was used, covered with a thin layer of gold. The effect was weak, but this invention is often associated with the beginning of the era of solar energy. Some scholars disagree with this statement. They call the founder of the era of solar energy the world famous scientist Albert Einstein. In 1921, he received the Nobel Prize for explaining the laws of the external photoelectric effect.
It would seem that solar energy is a promising way of development. But there are many obstacles for it to enter every home - mainly economic and environmental. Find out what the cost of solar panels is, what harm they can cause to the environment and what other methods of obtaining energy exist, we learn below.
Accumulation methods
The most urgent task associated with the taming of the energy of the sun is not only its receipt, but also the accumulation. And that is the most difficult thing. Currently, scientists have developed only 3 ways to fully tame solar energy.
The first is based on the use of a parabolic mirror and is a bit like playing with a magnifying glass, which everyone has known since childhood. Light passes through the lens, gathering at one point. If you put a piece of paper in this place, it will light up, because the temperature of the crossed sunlight is incredibly high. A parabolic mirror is a concave disk resembling a shallow bowl. This mirror, unlike a magnifier, does not let through, but reflects sunlight, collecting it at one point, which is usually directed to a black pipe with water. This color is used because it absorbs light best. The water in the pipe is heated by sunlight and can be used to generate electricity or to heat small houses.
Flat heater
This method uses a completely different system. The solar receiver looks like a multi-layer structure. The principle of his work looks like this.
Passing through the glass, the rays fall on a darkened metal, which, as you know, better absorbs light. Solar radiation is converted into thermal energy and heats the water that is under the iron plate. Further, everything happens as in the first method. Heated water can be used either for space heating or for generating electrical energy. True, the effectiveness of this method is not so high as to be used everywhere.
As a rule, solar energy obtained in this way is heat. To obtain electricity, the third method is much more often used.
Solar cells
Most of all, we are familiar with this way of generating energy. It involves the use of various batteries or solar panels, which can be found on the roofs of many modern houses. This method is more complicated than previously described, but is much more promising. It is he who makes it possible to convert the energy of the sun into electricity on an industrial scale.
Special panels designed to capture the rays are made from enriched silicon crystals. Sunlight, falling on them, knocks an electron from orbit. In its place, another immediately seeks, in this way a continuous moving chain is obtained, which creates a current. If necessary, it is immediately used to provide devices or is accumulated in the form of electricity in special batteries.
The popularity of this method is justified by the fact that it allows you to get more than 120 watts with just one square meter of solar panel. At the same time, the panels have a relatively small thickness, which allows them to be placed almost everywhere.
Types of Silicon Panels
There are several types of solar panels. The first are made using single-crystal silicon. Their efficiency is approximately 15%. Such solar panels are the most expensive.
The efficiency of elements made of polycrystalline silicon reaches 11%. They cost less, because the material for them is obtained by simplified technology. The third type is the most economical and has a minimum efficiency. These are panels made of amorphous silicon, i.e. non-crystalline. In addition to low efficiency, they have another significant drawback - fragility.
Some manufacturers use both sides of the solar panel, the back and the front, to increase efficiency. This allows you to capture light in large volumes and increases the amount of energy received by 15-20%.
Domestic manufacturers
Solar energy on Earth is becoming increasingly common. Even in our country, they are interested in studying this industry. Despite the fact that the development of alternative energy is not very active in Russia, some success has been achieved. Currently, several organizations are engaged in the creation of panels for the production of solar energy - mainly scientific institutions of various kinds and factories for the production of electrical equipment.
- NPF Quark.
- OJSC "Kovrov Mechanical Plant".
- All-Russian Research Institute of Electrification of Agriculture.
- NGO engineering.
- JSC VIEN.
- OJSC "Ryazan Plant of Ceramic Metal Devices".
- AOOT Pravdinsky pilot plant of current sources "Posit".
This is only a small part of enterprises that are actively involved in the development of alternative energy in Russia.
Environmental impact
The rejection of coal and oil energy sources is associated not only with the fact that these resources will end sooner or later. The fact is that they greatly harm the environment - they pollute the soil, air and water, contribute to the development of diseases in people and reduce immunity. That is why alternative energy sources must be environmentally friendly.
Silicon, which is used for the production of solar cells, is safe in itself because it is a natural material. But after cleaning it remains waste. They can harm humans and the environment if used improperly.
In addition, in a section completely covered by solar panels, natural light may be disturbed. This will lead to changes in the existing ecosystem. But in general, the environmental impact of devices designed to convert solar energy is minimal.
Cost-effectiveness
The largest costs for the production of solar cells are associated with the high cost of raw materials. As we have already found out, special panels are created using silicon. Despite the fact that this mineral is widespread in nature, big problems are associated with its extraction. The fact is that silicon, which makes up more than a quarter of the mass of the earth's crust, is not suitable for the production of solar cells. Only the purest material obtained industrially is suitable for these purposes. Unfortunately, obtaining pure silicon from sand is extremely problematic.
At a price this resource is comparable to uranium used at nuclear power plants. That is why the cost of solar panels currently remains at a fairly high level.
Modern technologies
The first attempts to tame solar energy appeared quite a long time ago. Since then, many scientists are actively engaged in the search for the most efficient equipment. It should be not only cost-effective, but also compact. Its efficiency should strive to the maximum.
The first steps to the ideal device for generating and converting solar energy were made with the invention of silicon batteries. Of course, the price is quite high, but the panels can be placed on the roofs and walls of houses, where they will not bother anyone. And the effectiveness of such batteries is undeniable.
But the best way to increase the popularity of solar energy is to make it cheaper. German scientists have already proposed replacing silicon with synthetic fibers that can be integrated into fabric or other materials. The efficiency of such a solar battery is not very high. But a shirt interspersed with synthetic fibers can at least provide electricity to a smartphone or player. Actively conducted work in the field of nanotechnology. It is likely that they will allow the sun to become the most popular source of energy in this century. Scates AS experts from Norway have already stated that nanotechnology will reduce the cost of solar panels by 2 times.
Solar energy for the home
Many will probably dream of housing that will provide for itself: there is no dependence on central heating, difficulties in paying bills and environmental damage. Already now, housing is being actively built in many countries, consuming only energy received from alternative sources. A vivid example is the so-called sunny house.
During the construction process, it will require more investment than traditional. But after several years of operation, all costs will pay off - you will not have to pay for heating, hot water and electricity. In a sunny house, all these communications are tied to special rooftop photovoltaic panels. Moreover, the energy resources obtained in this way are not only spent on current needs, but also accumulated for use at night and in cloudy weather.
Currently, the construction of such houses is conducted not only in countries close to the equator, where it is easiest to extract solar energy. They are also being built in Canada, Finland and Sweden.
Advantages and disadvantages
The development of technologies that allow the widespread use of solar energy could be conducted more actively. But there are certain reasons why this is still not a priority. As we said above, the production of panels produces substances harmful to the environment. In addition, the finished equipment contains gallium, arsenic, cadmium and lead.
The need for recycling photovoltaic panels raises many questions. After 50 years of work, they will become unsuitable for service, and they will have to be destroyed in some way. Could this cause tremendous harm to nature? It is also worth considering that solar energy is a variable resource, the effectiveness of which depends on the time of day and weather. And this is a significant drawback.
But there are pluses, of course. Solar energy can be extracted almost anywhere in the world, and the equipment for its production and conversion can be so small that it fits on the back of the smartphone. What is also important, this is a renewable resource, that is, the amount of solar energy will remain unchanged for at least another thousand years.
Prospects
The development of technologies in the field of solar energy should lead to lower costs for the creation of elements. Already there are glass panels that can be installed on the windows. The development of nanotechnology has allowed us to invent paint that will be sprayed onto solar panels and will be able to replace the silicon layer. If the cost of solar energy really decreases several times, its popularity will also grow many times over.
Creating small panels for individual use will allow people to use solar energy in any environment - at home, in the car or even outside the city. Thanks to their distribution, the load on centralized power networks will decrease, since people will be able to charge small electronics on their own.
Shell experts believe that by 2040, about half of the world's energy will be generated from renewable resources. Already in Germany, solar energy consumption is growing rapidly, and battery power is more than 35 gigawatts. Japan is also actively developing this industry. These two countries are leaders in the consumption of solar energy in the world. Probably soon the United States will join them.
Other alternative energy sources
Scientists do not stop racking their brains over what else can be used to generate electricity or heat. We give examples of the most promising alternative energy sources.
Windmills can now be found in almost any country. Even on the streets of many Russian cities, lanterns are installed, which themselves provide themselves with electricity through wind energy. Surely their cost is above average, but over time they will compensate for this difference.
Quite a long time ago a technology was invented that made it possible to obtain energy using the difference in water temperatures on the surface of the ocean and at depth. China is actively going to develop this direction. In the coming years, they are planning to build the largest power plant working on this technology off the coast of China. There are other ways to use the sea. For example, Australia plans to create a power plant that generates energy from currents.
There are many other ways to get electricity or heat. But against the background of many other options, solar energy is indeed a promising direction in the development of science.