People can no longer imagine life without electricity, and every year they need for energy is growing more and more, while the energy reserves of such oil, gas, coal are rapidly declining. Mankind has no other options but the use of alternative energy sources. One way to generate electricity is to convert solar energy using photocells. The fact that it is possible to use the energy of the sun, people learned relatively long ago but began to actively develop only in the last 20 years.
In recent years, thanks to ongoing research, the use of the latest materials and creative design solutions, it has been possible to significantly increase the performance of solar cells. Many believe that in the coming future 30% to 40% of the industrial energy consumption will be provided with the solar energy
Solar power source
Solar energy is one of the sources of electricity generation in a non-traditional way, therefore it refers to alternative energy sources. Solar energy uses solar radiation and converts it into electricity or other forms of energy. Solar energy is not only an environmentally friendly source of energy, because When converting solar energy, no harmful by-products are released, but solar energy is also a self-healing source of alternative energy.
How solar power works?
Theoretically, it is not difficult to calculate how much energy can be obtained from the flow of solar energy. It has long been known that having traveled the distance from the Sun to the Earth and falling onto a surface of 1 m² at a 90 ° angle, the solar flux at the entrance to the atmosphere carries an energy charge of 1367 W / m², this is the so-called solar constant. This is an ideal option under ideal conditions, which, as we know, is practically impossible to achieve.
Thus, after passing through the atmosphere, the maximum flux that can be obtained at the equator and will be 1020 W / m², but the average daily value that we can get will be 3 times less due to the change of day and night and the change in the angle of incidence of the solar flux. And in temperate latitudes, the change of seasons is also added to the change of day and night, and with it the change in the duration of daylight hours.
Development and distribution of solar energy
As we all know, in the past few years, the development of solar energy is gaining momentum every year, but let’s try to follow the dynamics of development. Back in 1985, global capacities using solar energy were only 0.021 GW. In 2005, they were already 1.656 GW. 2005 is considered a turning point in the development of solar energy, it was from this year that people began to be actively interested in the research and development of solar-powered electrical systems.
Further, the dynamics leave no doubt (2008–15.5 GW, 2009–22.8 GW, 2010–40 GW, 2011–70 GW, 2012–108 GW, 2013–150 GW, 2014–203 GW). The countries of the European Union and the USA hold the palm in the use of solar energy; more than 100 thousand people are employed in the production and operational sphere in the USA and Germany alone.
Not just solar energy production, there is also a lot of money being invested in commercial and household use for lights. Like the best outdoor solar string lights and landscape lights and the list goes on and on. This sector will thrive and grow out to become a huge industry in the near future.
Advantages and disadvantages of using solar energy
1) Environmental friendliness – does not pollute the environment
2) Availability – photocells are available for sale not only for industrial use, but also for the creation of private mini solar power plants
3) Inexhaustibility and recoverability of the energy source
4) The constantly decreasing cost of electricity production.
1) The impact on the performance of weather conditions and time of day
2) To save energy, it is necessary to accumulate energy
3) Lower productivity in temperate latitudes due to changing seasons
4) Significant heating of the air above the solar power station
5) The need to periodically clean the surface of the solar cells from contamination, and this is problematic because of the huge areas occupied by the installation of solar cells
6) We can also say about the relatively high cost of equipment, although every year the cost is reduced, while we can’t talk about cheap solar energy
Prospects for the Development of Solar Energy
Today, the development of solar energy is predicted for a great future, with each year more and more new solar power plants are being built, which amaze with their scale and technical solutions. Also, scientific research aimed at increasing the efficiency of photocells does not stop. Scientists calculated that if you cover the land of planet Earth by 0.07%, with an efficiency of photocells of 10%, then energy will be enough for more than 100% to meet all the needs of mankind.
To date, photocells with an efficiency of 30% are already used. According to research data, it is known that the ambitions of scientists promise to bring it up to 85%.
Solar power plants
Solar power plants are constructions whose task is to convert the flows of solar energy into electrical energy. The sizes of solar power plants can vary, ranging from private mini-power plants with several solar panels to huge ones covering an area of over 10 km².
What are solar power plants?
Since the construction of the first solar power plants, quite a lot of time has passed, during which many projects have been implemented and many interesting structural solutions have been applied. It is customary to divide all solar power plants into several types:
1. Tower-type solar power plants.
2. Solar power plants, where solar cells are photocells.
3. Plate-shaped solar power plants.
4. Parabolic solar power plants.
5. Solar power plants of the solar-vacuum type.
6. Solar power plants of a mixed type.
Tower-type solar power stations
A very common type of power plant design. It is a high tower structure on top of which a tank is located, painted black with water for better attraction of reflected sunlight. Around the tower in a circle there are large mirrors with an area of over 2 m², they are all connected to a single control system that monitors the change in the angle of inclination of the mirrors so that they always reflect sunlight and direct it directly to the water tank located at the top of the tower.
Thus, the reflected sunlight heats the water, which forms steam, and then this steam is pumped to the turbogenerator where electricity is generated. The heating temperature of the tank can reach 700 ° C. The height of the tower depends on the size and power of the solar power station and, as a rule.
Photovoltaic Solar Power Plants
Photocells (solar panels) are used to convert solar flux into electricity. This type of power plant has become very popular due to the possibility of using solar panels in small blocks, which allows the use of solar panels to provide electricity to both private homes and large industrial facilities. Moreover, the efficiency is growing every year and today photocells with an efficiency of 30% already exist.
Parabolic Solar Power
This type of solar power plant has the form of huge satellite dishes, the inside of which is covered with mirror plates. The principle by which energy is converted is similar to tower stations with a slight difference, the parabolic shape of the mirrors determines that the sun’s rays, reflected from the entire surface of the mirror, are concentrated in the center, where the receiver is located with the liquid, which heats up, forming steam that turns and is the driving force for small generators.
Plate-shaped solar power plants
The principle of operation and the method of generating electricity is identical to the solar power plants of the tower and parabolic type. The difference is only design features. On a stationary structure, it looks a bit like a giant metal tree on which round flat mirrors are hung that concentrate solar energy on the receiver.
Solar power plants, solar-vacuum type
This is a very unusual way to use the energy of the sun and the temperature difference. The construction of the power plant consists of a round-shaped glass-covered plot of land with a tower in the center. The tower inside is hollow, at its base, there are several turbines that rotate due to the flow of air arising due to the temperature difference. Through a glass roof, the sun heats the earth and air indoors, and the building communicates with the external environment through a pipe, and since the air temperature is much lower outside the building, air draft is created that increases with increasing temperature difference. Thus, at night, turbines generate more electricity than during the day.
Mixed-type solar power plants
This is when at solar power plants of a certain type, for example, solar collectors are used as auxiliary elements to provide objects with hot water and heat, or it is possible to simultaneously use sections of solar cells at tower-type power plants.
Solar energy is developing rapidly, people finally seriously think about alternative energy sources in order to prevent the inevitably impending energy crisis and environmental catastrophe. Although the United States and the European Union still remain leaders in solar energy, all other world powers are gradually beginning to adopt and use the experience and technologies of production and use of solar power plants. There is no doubt that sooner or later, solar energy will become the main source of energy on Earth.