In recent years, scientists have been particularly interested in alternative energy sources. Oil and gas will run out sooner or later, so we have to think about how we will survive in this situation now. Windmills are actively used in Europe, someone is trying to extract energy from the ocean, and we will talk about solar energy. After all, a star that we see almost every day in the sky can help us save non-renewable resources and improve the environment. The value of the sun for the Earth is difficult to overestimate - it gives heat, light and allows all life on the planet to function. So why not find another use for it?
A bit of history
In the middle of the 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 coated with a thin layer of gold was used. The effect was weak, but this invention is often associated with the beginning of the era of solar energy. Some scholars do not agree with this formulation. They call the founder of the era of solar energy the world famous scientist Albert Einstein. In 1921year 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. What makes up the cost of solar panels, what harm they can do to the environment and what other ways to generate energy, we will find out below.
Methods of savings
The most urgent task associated with taming the energy of the sun is not only its receipt, but also its accumulation. And that is what is most difficult. 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 is familiar to everyone 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 sun rays is incredibly high. A parabolic mirror is a concave disk resembling a shallow bowl. This mirror, unlike a magnifying glass, does not transmit, but reflects sunlight, collecting it at one point, which is usually directed to a black pipe with water. This color is used because it best absorbs light. 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 usesa completely different system. The solar energy receiver looks like a multilayer structure. The principle of its operation looks like this.
Passing through the glass, the rays hit the darkened metal, which, as you know, absorbs light better. Solar radiation turns into thermal energy and heats the water, which is under the iron plate. Further, everything happens as in the first method. The heated water can be used either for space heating or for generating electrical energy. True, the effectiveness of this method is not high enough to be used everywhere.
As a rule, the solar energy obtained in this way is heat. To generate electricity, the third method is much more often used.
Solar cells
Most of all we are familiar with this way of obtaining 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 solar energy into electricity on an industrial scale.
Special panels designed to capture rays are made from enriched silicon crystals. Sunlight, falling on them, knocks the electron out of orbit. Another one immediately strives to take its place, thus a continuous moving chain is obtained, which creates a current. If necessary, it is immediately used to provide devices or accumulated in the formelectricity in special batteries.
The popularity of this method is justified by the fact that it allows you to get more than 120 watts from just one square meter of solar panels. At the same time, the panels have a relatively small thickness, which allows them to be placed almost anywhere.
Types of silicon panels
There are several types of solar cells. The first are made using single-crystal silicon. Their efficiency is about 15%. These solar panels are the most expensive.
Efficiency of elements made of polycrystalline silicon reaches 11%. They cost less, since the material for them is obtained using a simplified technology. The third type is the most economical and has a minimum efficiency. These are panels made of amorphous silicon, that is, non-crystalline. In addition to low efficiency, they have another significant drawback - fragility.
Some manufacturers use both sides of the solar panel to increase efficiency - back and front. This allows you to capture light in large volumes and increases the amount of energy received by 15-20%.
Domestic producers
Solar energy on Earth is becoming more widespread. 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 solar energy - mainlyscientific institutes of various fields and factories for the production of electrical equipment.
- NPF "Kvark".
- OJSC Kovrov Mechanical Plant.
- All-Russian Research Institute of Electrification of Agriculture.
- NGO Engineering.
- AO VIEN.
- OJSC "Ryazan plant of metal-ceramic devices".
- JSC Pravdinsky Pilot Plant of Power Sources Pozit.
This is only a small part of the enterprises actively involved in the development of alternative energy in Russia.
Environmental impact
Rejection of coal and oil sources of energy is connected not only with the fact that these resources will run out 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 to make photovoltaic cells, is itself safe as it is a natural material. But after cleaning it, waste remains. They are the ones that can harm humans and the environment if used improperly.
In addition, in an area completely filled with solar panels, natural lighting may be disrupted. This will lead to changes in the existing ecosystem. But in general, the environmental impact of devices designed to convert solar energy is minimal.
Economy
The biggest costs for the production of solar panels 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 widely distributed in nature, there are big problems 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. For these purposes, only the purest material obtained by an industrial method is suitable. Unfortunately, getting the purest silicon from sand is extremely problematic.
The price of this resource is comparable to the uranium used in 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 a long time ago. Since then, many scientists have been 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 towards an ideal device for receiving 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 efficiency 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 intofabric 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. Work is also being actively carried out in the field of nanotechnology. It is likely that they will allow the sun to become the most popular source of energy this century. Scates AS specialists from Norway have already stated that nanotechnology will reduce the cost of solar panels by 2 times.
Solar energy for the home
Self-sustaining housing is the dream of many: no dependence on centralized heating, bill-paying hassles, and environmental harm. Already, many countries are actively building housing that consumes only energy obtained from alternative sources. A striking example is the so-called solar house.
During the construction process, it will require more investment than the traditional one. 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 solar house, all these communications are tied to special photovoltaic panels placed on the roof. 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 carried out not only in countries close to the equator, where it is easiest to obtain solar energy. They are also erected inCanada, Finland and Sweden.
Pros and cons
The development of technologies that allow the use of solar energy everywhere could be more active. But there are certain reasons why this is still not a priority. As we said above, during the production of panels, substances harmful to the environment are produced. In addition, the finished equipment contains gallium, arsenic, cadmium and lead.
The need to recycle photovoltaic panels also raises many questions. After 50 years of operation, they will become unusable and will have to be destroyed somehow. Will it cause enormous harm to nature? It is also worth considering that solar energy is a non-permanent resource, the efficiency of which depends on the time of day and weather. And this is a significant drawback.
But, of course, there are pluses. Solar energy can be mined almost anywhere on Earth, and the equipment to produce and convert it can be small enough to fit on the back of a smartphone. More importantly, it 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 a reduction in the cost of creating elements. Glass panels are already appearing that can be installed on windows. The development of nanotechnology has made it possible to invent a paint that will be sprayed onto solar panels and can replace the silicon layer. If the cost of solar energy really drops by 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 the centralized power grid will decrease, since people will be able to charge small electronics themselves.
Shell experts believe that by 2040 about half of the world's energy will be generated from renewable resources. Already now in Germany, the consumption of solar energy is actively growing, and the battery power is more than 35 Gigawatts. Japan is also actively developing this industry. These two countries are the leaders in the consumption of solar energy in the world. The United States is likely to join them soon.
Other alternative energy sources
Scientists do not stop puzzling over what else can be used to generate electricity or heat. Here are 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 that provide themselves with electricity from wind energy. Surely their cost is higher than average, but over time they will make up for this difference.
Quite a long time ago, a technology was invented that allows you to get energy usingdifference in water temperature at the surface of the ocean and at depth. China is actively going to develop this direction. In the coming years, off the coast of the Middle Kingdom, they are going to build the largest power plant operating on this technology. There are other ways to use the sea. For example, in Australia they plan to create a power plant that generates energy from the force of the currents.
There are many other ways to generate electricity or heat. But against the background of many other options, solar energy is really a promising direction in the development of science.
