The partial use of solar energy by humans has been practiced since ancient times. Focusing beams, Archimedes burned enemy ships, and medieval peasants heated the air in the towers, which rotated the blades of mills. However, the large-scale use of solar energy began only in the 20th century. And after a few more decades, this alternative source began to seriously crowd out traditional fuels in the energy market.
Applications of solar energy
In a relatively short period of time, humanity was able to “tame” the flow of light radiation and begin to apply its energy in the following areas:
- power supply for private households and industrial facilities;
- heating premises of any size and purpose – from apartments and private houses to agricultural greenhouses and livestock farms;
- heating water and / or converting it into steam for the subsequent conversion of solar energy into thermal and mechanical energy;
- lighting of houses, streets, green areas, service stations and other objects, and territories, especially those that do not have the ability to connect to power grids;
- the space industry, where photovoltaic batteries are often the only available means of generating energy.
Features and purpose of structures
All types of such systems can be divided into several classes.
By destination:
- Passive – are special materials or structures that maximize absorption of radiation and are designed to convert the sun’s energy into heat.
- Active – are systems, the purpose of which is not only absorption, but also transformation, and often accumulation of solar energy. These include all types of collectors, as well as photovoltaic batteries with batteries.
By conversion type:
- in heat;
- mechanical;
- electrical energy.
By complexity:
- simple – are ordinary materials or containers in which, under the influence of solar radiation, a carrier is heated;
- complex – high-tech structures capable of generating electric current, storing generated energy, controlled by automatic positioning systems, etc.
Photovoltaic panels
It is this type of structure that is most demanded today in the field of solar energy use by humans. Their most important advantage is functionality and versatility, which allows solar power plants to be used with equal efficiency on the ground and in space.
The use of solar cells based on semiconductor materials ranges from single panels to huge heliofarms of thousands of hectares.
The basis for any SPP, regardless of its size and power, is the following types of modules:
On monocrystalline / polycrystalline silicon. First generation, rigid structures. At present, they have an efficiency of 20-24% under the condition of ideal lighting, they are rapidly becoming cheaper and occupy about 2/3 of the world sales market.
On rare earth elements in the form of thin films. Second generation. In ground stations, panels with cells made of inexpensive cadmium telluride with an efficiency of 19-20% prevail. In the aerospace industry, solar energy conversion is carried out mainly by CIGS batteries using indium and gallium. More expensive, but effective – the efficiency reaches 35-40%.
Films on polymers, organics and quantum dots. Third generation. It is considered the most promising. At the moment, it has not yet received wide distribution due to unresolved issues with a short “life”.
Human use of solar energy by countries of the world
The number of installed small private and high-performance large solar power plants around the world is growing rapidly. In the most developed countries of the world, RES installations provide from 25 to 70% of all electricity consumed. According to the development plans of the USA, EU, China and some other countries and regions, by 2050 solar energy, along with other renewable energy sources, should provide almost 100% of their energy needs.
In Russia, the use of solar energy is still less popular, which is due to the traditionally low price for classical energy sources and weak government support. However, in just the last 3 years, the growth of capacities of new SPPs began to reach 250% per year.